{"collection":"philosophy-ethics","full_text_available":true,"graph_url":"https://unchartedknowledge.5gfusion.net/v2/api/page/gutenberg_52821/graph","html_url":"https://unchartedknowledge.5gfusion.net/v2/page/gutenberg_52821","id":"gutenberg_52821","license":"Public Domain (US)","rights_basis":"gutenberg_metadata_copyright_false","source":"gutenberg","source_url":"https://www.gutenberg.org/ebooks/52821","summary":null,"tags":["Category: Philosophy & Ethics","Knowledge, Theory of -- Early works to 1800","Metaphysics -- Early works to 1800"],"text":"KANT'S PROLEGOMENA\n\n\nTO ANY FUTURE METAPHYSICS\n\n\nEDITED IN ENGLISH\nBY\nDR. PAUL CARUS\n\n\nTHIRD EDITION\n\n\nCHICAGO\nTHE OPEN COURT PUBLISHING COMPANY\n1912\n\nTRANSLATION COPYRIGHTED\nBY\nThe Open Court Publishing Co.\n1902.\n\n\n[Transcriber's note: ** Supplemental material and table of contents\nare omitted from this etext. ** ]\n\n\n\nContents\n\nPUBLISHERS' PREFACE.\nINTRODUCTION.\nPROLEGOMENA.\n    PREAMBLE ON THE PECULIARITIES OF ALL METAPHYSICAL COGNITION.\nFIRST PART OF THE TRANSCENDENTAL PROBLEM.\n    HOW IS PURE MATHEMATICS POSSIBLE?\nSECOND PART OF THE TRANSCENDENTAL PROBLEM.\n    HOW IS THE SCIENCE OF NATURE POSSIBLE?\nTHIRD PART OF THE MAIN TRANSCENDENTAL PROBLEM.\n    HOW IS METAPHYSICS IN GENERAL POSSIBLE?\nSCHOLIA.\n    SOLUTION OF THE GENERAL QUESTION OF THE PROLEGOMENA, \"HOW IS\n    METAPHYSICS POSSIBLE AS A SCIENCE?\"\nAPPENDIX.\n    ON WHAT CAN BE DONE TO MAKE METAPHYSICS ACTUAL AS A SCIENCE.\n\n\n\n\nPUBLISHERS' PREFACE.\n\nKant's Prolegomena,{1} although a small book, is indubitably the most\nimportant of his writings. It furnishes us with a key to his main\nwork, The Critique of Pure Reason; in fact, it is an extract\ncontaining all the salient ideas of Kant's system. It approaches the\nsubject in the simplest and most direct way, and is therefore best\nadapted as an introduction into his philosophy. For this reason, The\nOpen Court Publishing Company has deemed it advisable to bring out a\nnew edition of the work, keeping in view its broader use as a\npreliminary survey and explanation of Kant's philosophy in general. In\norder to make the book useful for this broader purpose, the editor has\nnot only stated his own views concerning the problem underlying the\nProlegomena (see page 167 et seq.), but has also collected the most\nimportant materials which have reference to Kant's philosophy, or to\nthe reception which was accorded to it in various quarters (see page\n241 et seq.). The selections have not been made from a partisan\nstandpoint, but have been chosen with a view to characterising the\nattitude of different minds, and to directing the student to the best\nliterature on the subject.\n\n===================================\n{1} Prolegomena means literally prefatory or introductory remarks. It is\nthe neuter plural of the present passive participle of\n\u03c0\u03c1\u03bf\u03bb\u03ad\u03b3\u03b5\u03b9\u03bd, to speak before, i.e., to make introductory\nremarks before beginning one's regular discourse.\n===================================\n\nIt is not without good reasons that the appearance of the Critique of\nPure Reason is regarded as the beginning of a new era in the history\nof philosophy; and so it seems that a comprehension of Kant's\nposition, whether we accept or reject it, is indispensable to the\nstudent of philosophy. It is not his solution which makes the sage of\nK\u00f6nigsberg the initiator of modern thought, but his formulation of\nthe problem.\n\n* * *\n\nThe present translation is practically new, but it goes without saying\nthat the editor utilised the labors of his predecessors, among whom\nProf. John P. Mahaffy and John H. Bernard deserve special credit.\nRichardson's translation of 1818 may be regarded as superseded and has\nnot been consulted, but occasional reference has been made to that of\nProf. Ernest Belfort Bax. Considering the difficulties under which\neven these translators labored we must recognise the fact that they\ndid their work well, with painstaking diligence, great love of the\nsubject, and good judgment. The editor of the present translation has\nthe advantage of being to the manor born; moreover, he is pretty well\nversed in Kant's style; and wherever he differs from his predecessors\nin the interpretation of a construction, he has deviated from them not\nwithout good reasons. Nevertheless there are some passages which will\nstill remain doubtful, though happily they are of little consequence.\n\nAs a curiosum in Richardson's translation Professor Mahaffy mentions\nthat the words widersinnig gewundene Schnecken, which simply means\n\"symmetric helices,\"{2} are rendered by \"snails rolled up contrary to\nall sense\"\u2014a wording that is itself contrary to all sense and makes\nthe whole paragraph unintelligible. We may add an instance of another\nmistake that misses the mark. Kant employs in the Appendix a word that\nis no longer used in German. He speaks of the Cento der Metaphysik as\nhaving neue Lappen and einen ver\u00e4nderten Zuschnitt. Mr. Bax\ntranslates Cento by \"body,\" Lappen by \"outgrowths,\" and Zuschnitt by\n\"figure.\" His mistake is perhaps not less excusable than Richardson's;\nit is certainly not less comical, and it also destroys the sense,\nwhich in the present case is a very striking simile. Cento is a Latin\nword[3] derived from the Greek \u03ba\u03b5\u03bd\u03c4\u03c1\u03c9\u03bd,[4] meaning \"a garment of\nmany patches sewed together,\" or, as we might now say, \"a crazy\nquilt.\"\n\n===================================\n{2} Mahaffy not incorrectly translates \"spirals winding opposite ways,\"\nand Mr. Bax follows him verbatim even to the repetition of the\nfootnote.\n\n{3} The French cento is still in use.\n\n{4} \u03ba\u03ad\u03bd\u03c4\u03c1\u03c9\u03bd, (1) one that bears the marks of the \u03ba\u03ad\u03bd\u03c4\u03c1\u03bf,\ngoad; a rogue, (2) a patched cloth; (3) any kind of patchwork,\nespecially verses made up of scraps from other authors.\n===================================\n\n* * *\n\nIn the hope that this book will prove useful, The Open Court\nPublishing Company offers it as a help to the student of philosophy.\n\nP.C.\n\nINTRODUCTION.\n\nThese Prolegomena are destined for the use, not of pupils, but of\nfuture teachers, and even the latter should not expect that they will\nbe serviceable for the systematic exposition of a ready-made science,\nbut merely for the discovery of the science itself.\n\nThere are scholarly men, to whom the history of philosophy (both\nancient and modern) is philosophy itself; for these the present\nProlegomena are not written. They must wait till those who endeavor to\ndraw from the fountain of reason itself have completed their work; it\nwill then be the historian's turn to inform the world of what has been\ndone. Unfortunately, nothing can be said, which in their opinion has\nnot been said before, and truly the same prophecy applies to all\nfuture time; for since the human reason has for many centuries\nspeculated upon innumerable objects in various ways, it is hardly to\nbe expected that we should not be able to discover analogies for every\nnew idea among the old sayings of past ages.\n\nMy object is to persuade all those who think Metaphysics worth\nstudying, that it is absolutely necessary to pause a moment, and,\nneglecting all that has been done, to propose first the preliminary\nquestion, \u2018Whether such a thing as metaphysics be at all\npossible?\u2019\n\nIf it be a science, how comes it that it cannot, like other sciences,\nobtain universal and permanent recognition? If not, how can it\nmaintain its pretensions, and keep the human mind in suspense with\nhopes, never ceasing, yet never fulfilled? Whether then we demonstrate\nour knowledge or our ignorance in this field, we must come once for\nall to a definite conclusion respecting the nature of this so-called\nscience, which cannot possibly remain on its present footing. It seems\nalmost ridiculous, while every other science is continually advancing,\nthat in this, which pretends to be Wisdom incarnate, for whose oracle\nevery one inquires, we should constantly move round the same spot,\nwithout gaining a single step. And so its followers having melted\naway, we do not find men confident of their ability to shine in other\nsciences venturing their reputation here, where everybody, however\nignorant in other matters, may deliver a final verdict, as in this\ndomain there is as yet no standard weight and measure to distinguish\nsound knowledge from shallow talk.\n\nAfter all it is nothing extraordinary in the elaboration of a science,\nwhen men begin to wonder how far it has advanced, that the question\nshould at last occur, whether and how such a science is possible?\nHuman reason so delights in constructions, that it has several times\nbuilt up a tower, and then razed it to examine the nature of the\nfoundation. It is never too late to become wise; but if the change\ncomes late, there is always more difficulty in starting a reform.\n\nThe question whether a science be possible, presupposes a doubt as to\nits actuality. But such a doubt offends the men whose whole\npossessions consist of this supposed jewel; hence he who raises the\ndoubt must expect opposition from all sides. Some, in the proud\nconsciousness of their possessions, which are ancient, and therefore\nconsidered legitimate, will take their metaphysical compendia in their\nhands, and look down on him with contempt; others, who never see\nanything except it be identical with what they have seen before, will\nnot understand him, and everything will remain for a time, as if\nnothing had happened to excite the concern, or the hope, for an\nimpending change.\n\nNevertheless, I venture to predict that the independent reader of\nthese Prolegomena will not only doubt his previous science, but\nultimately be fully persuaded, that it cannot exist unless the demands\nhere stated on which its possibility depends, be satisfied; and, as\nthis has never been done, that there is, as yet, no such thing as\nMetaphysics. But as it can never cease to be in demand,{5}\u2014since the\ninterests of common sense are intimately interwoven with it, he must\nconfess that a radical reform, or rather a new birth of the science\nafter an original plan, are unavoidable, however men may struggle\nagainst it for a while.\n\n===================================\n{5} Says Horace:\n\"Rusticus expectat, dum defluat amnis, at ille\nLabitur et labetur in omne volubilis aevum;\"\n\"A rustic fellow waiteth on the shore\nFor the river to flow away,\nBut the river flows, and flows on as before,\nAnd it flows forever and aye.\"\n===================================\n\nSince the Essays of Locke and Leibnitz, or rather since the origin of\nmetaphysics so far as we know its history, nothing has ever happened\nwhich was more decisive to its fate than the attack made upon it by\nDavid Hume. He threw no light on this species of knowledge, but he\ncertainly struck a spark from which light might have been obtained,\nhad it caught some inflammable substance and had its smouldering fire\nbeen carefully nursed and developed.\n\nHume started from a single but important concept in Metaphysics, viz.,\nthat of Cause and Effect (including its derivatives force and action,\netc.). He challenges reason, which pretends to have given birth to\nthis idea from herself, to answer him by what right she thinks\nanything to be so constituted, that if that thing be posited,\nsomething else also must necessarily be posited; for this is the\nmeaning of the concept of cause. He demonstrated irrefutably that it\nwas perfectly impossible for reason to think a priori and by means of\nconcepts a combination involving necessity. We cannot at all see why,\nin consequence of the existence of one thing, another must necessarily\nexist, or how the concept of such a combination can arise a priori.\nHence he inferred, that reason was altogether deluded with reference\nto this concept, which she erroneously considered as one of her\nchildren, whereas in reality it was nothing but a bastard of\nimagination, impregnated by experience, which subsumed certain\nrepresentations under the Law of Association, and mistook the\nsubjective necessity of habit for an objective necessity arising from\ninsight. Hence he inferred that reason had no power to think such\ncombinations, even generally, because her concepts would then be\npurely fictitious, and all her pretended a priori cognitions nothing\nbut common experiences marked with a false stamp. In plain language\nthere is not, and cannot be, any such thing as metaphysics at all.{6}\n\n===================================\n{6} Nevertheless Hume called this very destructive science metaphysics\nand attached to it great value. Metaphysics and morals [he declares in\nthe fourth part of his Essays] are the most important branches of\nscience; mathematics and physics are not nearly so important. But the\nacute man merely regarded the negative use arising from the moderation\nof extravagant claims of speculative reason, and the complete\nsettlement of the many endless and troublesome controversies that\nmislead mankind. He overlooked the positive injury which results, if\nreason be deprived of its most important prospects, which can alone\nsupply to the will the highest aim for all its endeavor.\n===================================\n\nHowever hasty and mistaken Hume's conclusion may appear, it was at\nleast founded upon investigation, and this investigation deserved the\nconcentrated attention of the brighter spirits of his day as well as\ndetermined efforts on their part to discover, if possible, a happier\nsolution of the problem in the sense proposed by him, all of which\nwould have speedily resulted in a complete reform of the science.\n\nBut Hume suffered the usual misfortune of metaphysicians, of not being\nunderstood. It is positively painful to see how utterly his opponents,\nReid, Oswald, Beattie, and lastly Priestley, missed the point of the\nproblem; for while they were ever taking for granted that which he\ndoubted, and demonstrating with zeal and often with impudence that\nwhich he never thought of doubting, they so misconstrued his valuable\nsuggestion that everything remained in its old condition, as if\nnothing had happened.\n\nThe question was not whether the concept of cause was right, useful,\nand even indispensable for our knowledge of nature, for this Hume had\nnever doubted; but whether that concept could be thought by reason a\npriori, and consequently whether it possessed an inner truth,\nindependent of all experience, implying a wider application than\nmerely to the objects of experience. This was Hume's problem. It was a\nquestion concerning the origin, not concerning the indispensable need\nof the concept. Were the former decided, the conditions of the use and\nthe sphere of its valid application would have been determined as a\nmatter of course.\n\nBut to satisfy the conditions of the problem, the opponents of the\ngreat thinker should have penetrated very deeply into the nature of\nreason, so far as it is concerned with pure thinking,\u2014a task which\ndid not suit them. They found a more convenient method of being\ndefiant without any insight, viz., the appeal to common sense. It is\nindeed a great gift of God, to possess right, or (as they now call it)\nplain common sense. But this common sense must be shown practically,\nby well-considered and reasonable thoughts and words, not by appealing\nto it as an oracle, when no rational justification can be advanced. To\nappeal to common sense, when insight and science fail, and no\nsooner\u2014this is one of the subtile discoveries of modern times, by\nmeans of which the most superficial ranter can safely enter the lists\nwith the most thorough thinker, and hold his own. But as long as a\nparticle of insight remains, no one would think of having recourse to\nthis subterfuge. For what is it but an appeal to the opinion of the\nmultitude, of whose applause the philosopher is ashamed, while the\npopular charlatan glories and confides in it? I should think that Hume\nmight fairly have laid as much claim to common sense as Beattie, and\nin addition to a critical reason (such as the latter did not possess),\nwhich keeps common sense in check and prevents it from speculating,\nor, if speculations are under discussion, restrains the desire to\ndecide because it cannot satisfy itself concerning its own arguments.\nBy this means alone can common sense remain sound. Chisels and hammers\nmay suffice to work a piece of wood, but for steel-engraving we\nrequire an engraver's needle. Thus common sense and speculative\nunderstanding are each serviceable in their own way, the former in\njudgments which apply immediately to experience, the latter when we\njudge universally from mere concepts, as in metaphysics, where sound\ncommon sense, so called in spite of the inapplicability of the word,\nhas no right to judge at all.\n\nI openly confess, the suggestion of David Hume was the very thing,\nwhich many years ago first interrupted my dogmatic slumber, and gave\nmy investigations in the field of speculative philosophy quite a new\ndirection. I was far from following him in the conclusions at which he\narrived by regarding, not the whole of his problem, but a part, which\nby itself can give us no information. If we start from a well-founded,\nbut undeveloped, thought, which another has bequeathed to us, we may\nwell hope by continued reflection to advance farther than the acute\nman, to whom we owe the first spark of light.\n\nI therefore first tried whether Hume's objection could not be put into\na general form, and soon found that the concept of the connexion of\ncause and effect was by no means the only idea by which the\nunderstanding thinks the connexion of things a priori, but rather that\nmetaphysics consists altogether of such connexions. I sought to\nascertain their number, and when I had satisfactorily succeeded in\nthis by starting from a single principle, I proceeded to the deduction\nof these concepts, which I was now certain were not deduced from\nexperience, as Hume had apprehended, but sprang from the pure\nunderstanding. This deduction (which seemed impossible to my acute\npredecessor, which had never even occurred to any one else, though no\none had hesitated to use the concepts without investigating the basis\nof their objective validity) was the most difficult task ever\nundertaken in the service of metaphysics; and the worst was that\nmetaphysics, such as it then existed, could not assist me in the\nleast, because this deduction alone can render metaphysics possible.\nBut as soon as I had succeeded in solving Hume's problem not merely in\na particular case, but with respect to the whole faculty of pure\nreason, I could proceed safely, though slowly, to determine the whole\nsphere of pure reason completely and from general principles, in its\ncircumference as well as in its contents. This was required for\nmetaphysics in order to construct its system according to a reliable\nmethod.\n\nBut I fear that the execution of Hume's problem in its widest extent\n(viz., my Critique of the Pure Reason) will fare as the problem itself\nfared, when first proposed. It will be misjudged because it is\nmisunderstood, and misunderstood because men choose to skim through\nthe book, and not to think through it\u2014a disagreeable task, because\nthe work is dry, obscure, opposed to all ordinary notions, and\nmoreover long-winded. I confess, however, I did not expect to hear\nfrom philosophers complaints of want of popularity, entertainment, and\nfacility, when the existence of a highly prized and indispensable\ncognition is at stake, which cannot be established otherwise than by\nthe strictest rules of methodic precision. Popularity may follow, but\nis inadmissible at the beginning. Yet as regards a certain obscurity,\narising partly from the diffuseness of the plan, owing to which the\nprincipal points of the investigation are easily lost sight of, the\ncomplaint is just, and I intend to remove it by the present\nProlegomena.\n\nThe first-mentioned work, which discusses the pure faculty of reason\nin its whole compass and bounds, will remain the foundation, to which\nthe Prolegomena, as a preliminary exercise, refer; for our critique\nmust first be established as a complete and perfected science, before\nwe can think of letting Metaphysics appear on the scene, or even have\nthe most distant hope of attaining it.\n\nWe have been long accustomed to seeing antiquated knowledge produced\nas new by taking it out of its former context, and reducing it to\nsystem in a new suit of any fancy pattern under new titles. Most\nreaders will set out by expecting nothing else from the Critique; but\nthese Prolegomena may persuade him that it is a perfectly new science,\nof which no one has ever even thought, the very idea of which was\nunknown, and for which nothing hitherto accomplished can be of the\nsmallest use, except it be the suggestion of Hume's doubts. Yet ever,\nhe did not suspect such a formal science, but ran his ship ashore, for\nsafety's sake, landing on scepticism, there to let it lie and rot;\nwhereas my object is rather to give it a pilot, who, by means of safe\nastronomical principles drawn from a knowledge of the globe, and\nprovided with a complete chart and compass, may steer the ship safely,\nwhither he listeth.\n\nIf in a new science, which is wholly isolated and unique in its kind,\nwe started with the prejudice that we can judge of things by means of\nour previously acquired knowledge, which is precisely what has first\nto be called in question, we should only fancy we saw everywhere what\nwe had already known, the expressions, having a similar sound, only\nthat all would appear utterly metamorphosed, senseless and\nunintelligible, because we should have as a foundation our own\nnotions, made by long habit a second nature, instead of the author's.\nBut the longwindedness of the work, so far as it depends on the\nsubject, and not the exposition, its consequent unavoidable dryness\nand its scholastic precision are qualities which can only benefit the\nscience, though they may discredit the book.\n\nFew writers are gifted with the subtilty, and at the same time with\nthe grace, of David Hume, or with the depth, as well as the elegance,\nof Moses Mendelssohn. Yet I flatter myself I might have made my own\nexposition popular, had my object been merely to sketch out a plan and\nleave its completion to others, instead of having my heart in the\nwelfare of the science, to which I had devoted myself so long; in\ntruth, it required no little constancy, and even self-denial, to\npostpone the sweets of an immediate success to the prospect of a\nslower, but more lasting, reputation.\n\nMaking plans is often the occupation of an opulent and boastful mind,\nwhich thus obtains the reputation of a creative genius, by demanding\nwhat it cannot itself supply; by censuring, what it cannot improve;\nand by proposing, what it knows not where to find. And yet something\nmore should belong to a sound plan of a general critique of pure\nreason than mere conjectures, if this plan is to be other than the\nusual declamations of pious aspirations. But pure reason is a sphere\nso separate and self-contained, that we cannot touch a part without\naffecting all the rest. We can therefore do nothing without first\ndetermining the position of each part, and its relation to the rest;\nfor, as our judgment cannot be corrected by anything without, the\nvalidity and use of every part depends upon the relation in which it\nstands to all the rest within the domain of reason.\n\nSo in the structure of an organized body, the end of each member can\nonly be deduced from the full conception of the whole. It may, then,\nbe said of such a critique that it is never trustworthy except it be\nperfectly complete, down to the smallest elements of pure reason. In\nthe sphere of this faculty you can determine either everything or\nnothing.\n\nBut although a mere sketch, preceding the Critique of Pure Reason,\nwould be unintelligible, unreliable, and useless, it is all the more\nuseful as a sequel. For so we are able to grasp the whole, to examine\nin detail the chief points of importance in the science, and to\nimprove in many respects our exposition, as compared with the first\nexecution of the work.\n\nAfter the completion of the work I offer here such a plan which is\nsketched out after an analytical method, while the work itself had to\nbe executed in the synthetical style, in order that the science may\npresent all its articulations, as the structure of a peculiar\ncognitive faculty, in their natural combination. But should any reader\nfind this plan, which I publish as the Prolegomena to any future\nMetaphysics, still obscure, let him consider that not every one is\nbound to study Metaphysics, that many minds will succeed very well, in\nthe exact and even in deep sciences, more closely allied to practical\nexperience,{7} while they cannot succeed in investigations dealing\nexclusively with abstract concepts. In such cases men should apply\ntheir talents to other subjects. But he who undertakes to judge, or\nstill more, to construct, a system of Metaphysics, must satisfy the\ndemands here made, either by adopting my solution, or by thoroughly\nrefuting it, and substituting another. To evade it is impossible.\n\n===================================\n{7} The term Anschauung here used means sense-perception. It is that\nwhich is given to the senses and apprehended immediately, as an object\nis seen by merely looking at it. The translation intuition, though\netymologically correct, is misleading. In the present passage the term\nis not used in its technical significance but means \"practical\nexperience.\"\u2014Ed.\n===================================\n\nIn conclusion, let it be remembered that this much-abused obscurity\n(frequently serving as a mere pretext under which people hide their\nown indolence or dullness) has its uses, since all who in other\nsciences observe a judicious silence, speak authoritatively in\nmetaphysics and make bold decisions, because their ignorance is not\nhere contrasted with the knowledge of others. Yet it does contrast\nwith sound critical principles, which we may therefore commend in the\nwords of Virgil:\n\n\"Ignavum, fucos, pecus a praesepibus arcent.\"\n\"Bees are defending their hives against drones, those indolent\ncreatures.\"\n\nPROLEGOMENA.\n\nPREAMBLE ON THE PECULIARITIES OF ALL METAPHYSICAL COGNITION.\n\n\u00a7 1. Of the Sources of Metaphysics.\n\nIf it becomes desirable to formulate any cognition as science, it will\nbe necessary first to determine accurately those peculiar features\nwhich no other science has in common with it, constituting its\ncharacteristics; otherwise the boundaries of all sciences become\nconfused, and none of them can be treated thoroughly according to its\nnature.\n\nThe characteristics of a science may consist of a simple difference of\nobject, or of the sources of cognition, or of the kind of cognition,\nor perhaps of all three conjointly. On this, therefore, depends the\nidea of a possible science and its territory.\n\nFirst, as concerns the sources of metaphysical cognition, its very\nconcept implies that they cannot be empirical. Its principles\n(including not only its maxims but its basic notions) must never be\nderived from experience. It must not be physical but metaphysical\nknowledge, viz., knowledge lying beyond experience. It can therefore\nhave for its basis neither external experience, which is the source of\nphysics proper, nor internal, which is the basis of empirical\npsychology. It is therefore a priori knowledge, coming from pure\nUnderstanding and pure Reason.\n\nBut so far Metaphysics would not be distinguish able from pure\nMathematics; it must therefore be called pure philosophical cognition;\nand for the meaning of this term I refer to the Critique of the Pure\nReason (II. \"Method of Transcendentalism,\" Chap. I., Sec. i), where\nthe distinction between these two employments of the reason is\nsufficiently explained. So far concerning the sources of metaphysical\ncognition.\n\n\u00a7 2. Concerning the Kind of Cognition which can alone be called\nMetaphysical.\n\na. Of the Distinction between Analytical and Synthetical Judgments in\ngeneral.\u2014The peculiarity of its sources demands that metaphysical\ncognition must consist of nothing but a priori judgments. But whatever\nbe their origin, or their logical form, there is a distinction in\njudgments, as to their content, according to which they are either\nmerely explicative, adding nothing to the content of the cognition, or\nexpansive, increasing the given cognition: the former may be called\nanalytical, the latter synthetical, judgments.\n\nAnalytical judgments express nothing in the predicate but what has\nbeen already actually thought in the concept of the subject, though\nnot so distinctly or with the same (full) consciousness. When I say:\nAll bodies are extended, I have not amplified in the least my concept\nof body, but have only analysed it, as extension was really thought to\nbelong to that concept before the judgment was made, though it was not\nexpressed; this judgment is therefore analytical. On the contrary,\nthis judgment, All bodies have weight, contains in its predicate\nsomething not actually thought in the general concept of the body; it\namplifies my knowledge by adding something to my concept, and must\ntherefore be called synthetical.\n\nb. The Common Principle of all Analytical Judgments is the Law of\nContradiction.\u2014All analytical judgments depend wholly on the law of\nContradiction, and are in their nature a priori cognitions, whether\nthe concepts that supply them with matter be empirical or not. For the\npredicate of an affirmative analytical judgment is already contained\nin the concept of the subject, of which it cannot be denied without\ncontradiction. In the same way its opposite is necessarily denied of\nthe subject in an analytical, but negative, judgment, by the same law\nof contradiction. Such is the nature of the judgments: all bodies are\nextended, and no bodies are unextended (i.e., simple).\n\nFor this very reason all analytical judgments are a priori even when\nthe concepts are empirical, as, for example, Gold is a yellow metal;\nfor to know this I require no experience beyond my concept of gold as\na yellow metal: it is, in fact, the very concept, and I need only\nanalyse it, without looking beyond it elsewhere.\n\nc. Synthetical Judgments require a different Principle from the Law of\nContradiction.\u2014There are synthetical a posteriori judgments of\nempirical origin; but there are also others which are proved to be\ncertain a priori, and which spring from pure Understanding and Reason.\nYet they both agree in this, that they cannot possibly spring from the\nprinciple of analysis, viz., the law of contradiction, alone; they\nrequire a quite different principle, though, from whatever they may be\ndeduced, they must be subject to the law of contradiction, which must\nnever be violated, even though everything cannot be deduced from it. I\nshall first classify synthetical judgments.\n\n1. Empirical Judgments are always synthetical. For it would be absurd\nto base an analytical judgment on experience, as our concept suffices\nfor the purpose without requiring any testimony from experience. That\nbody is extended, is a judgment established a priori, and not an\nempirical judgment. For before appealing to experience, we already\nhave all the conditions of the judgment in the concept, from which we\nhave but to elicit the predicate according to the law of\ncontradiction, and thereby to become conscious of the necessity of the\njudgment, which experience could not even teach us.\n\n2. Mathematical Judgments are all synthetical. This fact seems\nhitherto to have altogether escaped the observation of those who have\nanalysed human reason; it even seems directly opposed to all their\nconjectures, though incontestably certain, and most important in its\nconsequences. For as it was found that the conclusions of\nmathematicians all proceed according to the law of contradiction (as\nis demanded by all apodeictic certainty), men persuaded themselves\nthat the fundamental principles were known from the same law. This was\na great mistake, for a synthetical proposition can indeed be\ncomprehended according to the law of contradiction, but only by\npresupposing another synthetical proposition from which it follows,\nbut never in itself.\n\nFirst of all, we must observe that all proper mathematical judgments\nare a priori, and not empirical, because they carry with them\nnecessity, which cannot be obtained from experience. But if this be\nnot conceded to me, very good; I shall confine my assertion to pure\nMathematics, the very notion of which implies that it contains pure a\npriori and not empirical cognitions.\n\nIt might at first be thought that the proposition 7 + 5 = 12 is a mere\nanalytical judgment, following from the concept of the sum of seven\nand five, according to the law of contradiction. But on closer\nexamination it appears that the concept of the sum of 7 + 5 contains\nmerely their union in a single number, without its being at all\nthought what the particular number is that unites them. The concept of\ntwelve is by no means thought by merely thinking of the combination of\nseven and five; and analyse this possible sum as we may, we shall not\ndiscover twelve in the concept. We must go beyond these concepts, by\ncalling to our aid some concrete image (Anschauung), i.e., either our\nfive fingers, or five points (as Segner has it in his Arithmetic), and\nwe must add successively the units of the five, given in some concrete\nimage (Anschauung), to the concept of seven. Hence our concept is\nreally amplified by the proposition 7 + 5 = 12, and we add to the\nfirst a second, not thought in it. Arithmetical judgments are\ntherefore synthetical, and the more plainly according as we take\nlarger numbers; for in such cases it is clear that, however closely we\nanalyse our concepts without calling visual images (Anschauung) to our\naid, we can never find the sum by such mere dissection.\n\nAll principles of geometry are no less analytical. That a straight\nline is the shortest path between two points, is a synthetical\nproposition. For my concept of straight contains nothing of quantity,\nbut only a quality. The attribute of shortness is therefore altogether\nadditional, and cannot be obtained by any analysis of the concept.\nHere, too, visualisation (Anschauung) must come to aid us. It alone\nmakes the synthesis possible.\n\nSome other principles, assumed by geometers, are indeed actually\nanalytical, and depend on the law of contradiction; but they only\nserve, as identical propositions, as a method of concatenation, and\nnot as principles, e.g., a = a, the whole is equal to itself, or a + b\n> a, the whole is greater than its part. And yet even these, though\nthey are recognised as valid from mere concepts, are only admitted in\nmathematics, because they can be represented in some visual form\n(Anschauung). What usually makes us believe that the predicate of such\napodeictic{8} judgments is already contained in our concept, and that\nthe judgment is therefore analytical, is the duplicity of the\nexpression, requesting us to think a certain predicate as of necessity\nimplied in the thought of a given concept, which necessity attaches to\nthe concept. But the question is not what we are requested to join in\nthought to the given concept, but what we actually think together with\nand in it, though obscurely; and so it appears that the predicate\nbelongs to these concepts necessarily indeed, yet not directly but\nindirectly by an added visualisation (Anschauung).\n\n===================================\n{8} The term apodeictic is borrowed by Kant from Aristotle who uses it\nin the sense of \"certain beyond dispute.\" The word is derived from\n\u1f00\u03c0\u03bf\u03b4\u03b5\u03af\u03ba\u03bd\u03c5\u03bc\u03b9 (= I show) and is contrasted to dialectic\npropositions, i.e., such statements as admit of controversy.\u2014Ed.\n===================================\n\n\u00a7 3. A Remark on the General Division of Judgments into Analytical\nand Synthetical.\n\nThis division is indispensable, as concerns the Critique of human\nunderstanding, and therefore deserves to be called classical, though\notherwise it is of little use, but this is the reason why dogmatic\nphilosophers, who always seek the sources of metaphysical judgments in\nMetaphysics itself, and not apart from it, in the pure laws of reason\ngenerally, altogether neglected this apparently obvious distinction.\nThus the celebrated Wolf, and his acute follower Baumgarten, came to\nseek the proof of the principle of Sufficient Reason, which is clearly\nsynthetical, in the principle of Contradiction. In Locke's Essay,\nhowever, I find an indication of my division. For in the fourth book\n(chap.\u00a0iii. \u00a7 9, seq.), having discussed the various connexions of\nrepresentations in judgments, and their sources, one of which he makes\n\"identity and contradiction\" (analytical judgments), and another the\ncoexistence of representations in a subject, he confesses (\u00a7 10) that\nour a priori knowledge of the latter is very narrow, and almost\nnothing. But in his remarks on this species of cognition, there is so\nlittle of what is definite, and reduced to rules, that we cannot\nwonder if no one, not even Hume, was led to make investigations\nconcerning this sort of judgments. For such general and yet definite\nprinciples are not easily learned from other men, who have had them\nobscurely in their minds. We must hit on them first by our own\nreflexion, then we find them elsewhere, where we could not possibly\nhave found them at first, because the authors themselves did not know\nthat such an idea lay at the basis of their observations. Men who\nnever think independently have nevertheless the acuteness to discover\neverything, after it has been once shown them, in what was said long\nsince, though no one ever saw it there before.\n\n\u00a7 4. The General Question of the Prolegomena.\u2014Is Metaphysics at all\nPossible?\n\nWere a metaphysics, which could maintain its place as a science,\nreally in existence; could we say, here is metaphysics, learn it, and\nit will convince you irresistibly and irrevocably of its truth: this\nquestion would be useless, and there would only remain that other\nquestion (which would rather be a test of our acuteness, than a proof\nof the existence of the thing itself), \"How is the science possible,\nand how does reason come to attain it?\" But human reason has not been\nso fortunate in this case. There is no single book to which you can\npoint as you do to Euclid, and say: This is Metaphysics; here you may\nfind the noblest objects of this science, the knowledge of a highest\nBeing, and of a future existence, proved from principles of pure\nreason. We can be shown indeed many judgments, demonstrably certain,\nand never questioned; but these are all analytical, and rather concern\nthe materials and the scaffolding for Metaphysics, than the extension\nof knowledge, which is our proper object in studying it (\u00a7 2). Even\nsupposing you produce synthetical judgments (such as the law of\nSufficient Reason, which you have never proved, as you ought to, from\npure reason a priori, though we gladly concede its truth), you lapse\nwhen they come to be employed for your principal object, into such\ndoubtful assertions, that in all ages one Metaphysics has contradicted\nanother, either in its assertions, or their proofs, and thus has\nitself destroyed its own claim to lasting assent. Nay, the very\nattempts to set up such a science are the main cause of the early\nappearance of scepticism, a mental attitude in which reason treats\nitself with such violence that it could never have arisen save from\ncomplete despair of ever satisfying our most important aspirations.\nFor long before men began to inquire into nature methodically, they\nconsulted abstract reason, which had to some extent been exercised by\nmeans of ordinary experience; for reason is ever present, while laws\nof nature must usually be discovered with labor. So Metaphysics\nfloated to the surface, like foam, which dissolved the moment it was\nscooped off. But immediately there appeared a new supply on the\nsurface, to be ever eagerly gathered up by some, while others, instead\nof seeking in the depths the cause of the phenomenon, thought they\nshowed their wisdom by ridiculing the idle labor of their neighbors.\n\nThe essential and distinguishing feature of pure mathematical\ncognition among all other a priori cognitions is, that it cannot at\nall proceed from concepts, but only by means of the construction of\nconcepts (see Critique II., Method of Transcendentalism, chap. I.,\nsect. 1). As therefore in its judgments it must proceed beyond the\nconcept to that which its corresponding visualisation (Anschauung)\ncontains, these judgments neither can, nor ought to, arise\nanalytically, by dissecting the concept, but are all synthetical.\n\nI cannot refrain from pointing out the disadvantage resulting to\nphilosophy from the neglect of this easy and apparently insignificant\nobservation. Hume being prompted (a task worthy of a philosopher) to\ncast his eye over the whole field of a priori cognitions in which\nhuman understanding claims such mighty possessions, heedlessly severed\nfrom it a whole, and indeed its most valuable, province, viz., pure\nmathematics; for he thought its nature, or, so to speak, the\nstate-constitution of this empire, depended on totally different\nprinciples, namely, on the law of contradiction alone; and although he\ndid not divide Judgments in this manner formally and universally as I\nhave done here, what he said was equivalent to this: that mathematics\ncontains only analytical, but metaphysics synthetical, a priori\njudgments. In this, however, he was greatly mistaken, and the mistake\nhad a decidedly injurious effect upon his whole conception. But for\nthis, he would have extended his question concerning the origin of our\nsynthetical judgments far beyond the metaphysical concept of\nCausality, and included in it the possibility of mathematics a priori\nalso, for this latter he must have assumed to be equally synthetical.\nAnd then he could not have based his metaphysical judgments on mere\nexperience without subjecting the axioms of mathematics equally to\nexperience, a thing which he was far too acute to do. The good company\ninto which metaphysics would thus have been brought, would have saved\nit from the danger of a contemptuous ill-treatment, for the thrust\nintended for it must have reached mathematics, which was not and could\nnot have been Hume's intention. Thus that acute man would have been\nled into considerations which must needs be similar to those that now\noccupy us, but which would have gained inestimably by his inimitably\nelegant style.\n\nMetaphysical judgments, properly so called, are all synthetical. We\nmust distinguish judgments pertaining to metaphysics from metaphysical\njudgments properly so called. Many of the former are analytical, but\nthey only afford the means for metaphysical judgments, which are the\nwhole end of the science, and which are always synthetical. For if\nthere be concepts pertaining to metaphysics (as, for example, that of\nsubstance), the judgments springing from simple analysis of them also\npertain to metaphysics, as, for example, substance is that which only\nexists as subject; and by means of several such analytical judgments,\nwe seek to approach the definition of the concept. But as the analysis\nof a pure concept of the understanding pertaining to metaphysics, does\nnot proceed in any different manner from the dissection of any other,\neven empirical, concepts, not pertaining to metaphysics (such as: air\nis an elastic fluid, the elasticity of which is not destroyed by any\nknown degree of cold), it follows that the concept indeed, but not the\nanalytical judgment, is properly metaphysical. This science has\nsomething peculiar in the production of its a priori cognitions, which\nmust therefore be distinguished from the features it has in common\nwith other rational knowledge. Thus the judgment, that all the\nsubstance in things is permanent, is a synthetical and properly\nmetaphysical judgment.\n\nIf the a priori principles, which constitute the materials of\nmetaphysics, have first been collected according to fixed principles,\nthen their analysis will be of great value; it might be taught as a\nparticular part (as a philosophia definitiva), containing nothing but\nanalytical judgments pertaining to metaphysics, and could be treated\nseparately from the synthetical which constitute metaphysics proper.\nFor indeed these analyses are not elsewhere of much value, except in\nmetaphysics, i.e., as regards the synthetical judgments, which are to\nbe generated by these previously analysed concepts.\n\nThe conclusion drawn in this section then is, that metaphysics is\nproperly concerned with synethetical propositions a priori, and these\nalone constitute its end, for which it indeed requires various\ndissections of its concepts, viz., of its analytical judgments, but\nwherein the procedure is not different from that in every other kind\nof knowledge, in which we merely seek to render our concepts distinct\nby analysis. But the generation of a priori cognition by concrete\nimages as well as by concepts, in fine of synthetical propositions a\npriori in philosophical cognition, constitutes the essential subject\nof Metaphysics.\n\nWeary therefore as well of dogmatism, which teaches us nothing, as of\nscepticism, which does not even promise us anything, not even the\nquiet state of a contented ignorance; disquieted by the importance of\nknowledge so much needed; and lastly, rendered suspicious by long\nexperience of all knowledge which we believe we possess, or which\noffers itself, under the title of pure reason: there remains but one\ncritical question on the answer to which our future procedure depends,\nviz., Is Metaphysics at all possible? But this question must be\nanswered not by sceptical objections to the asseverations of some\nactual system of metaphysics (for we do not as yet admit such a thing\nto exist), but from the conception, as yet only problematical, of a\nscience of this sort.\n\nIn the Critique of Pure Reason I have treated this question\nsynthetically, by making inquiries into pure reason itself, and\nendeavoring in this source to determine the elements as well as the\nlaws of its pure use according to principles. The task is difficult,\nand requires a resolute reader to penetrate by degrees into a system,\nbased on no data except reason itself, and which therefore seeks,\nwithout resting upon any fact, to unfold knowledge from its original\ngerms. Prolegomena, however, are designed for preparatory exercises;\nthey are intended rather to point out what we have to do in order if\npossible to actualise a science, than to propound it. They must\ntherefore rest upon something already known as trustworthy, from which\nwe can set out with confidence, and ascend to sources as yet unknown,\nthe discovery of which will not only explain to us what we knew, but\nexhibit a sphere of many cognitions which all spring from the same\nsources. The method of Prolegomena, especially of those designed as a\npreparation for future metaphysics, is consequently analytical.\n\nBut it happens fortunately, that though we cannot assume metaphysics\nto be an actual science, we can say with confidence that certain pure\na priori synthetical cognitions, pure Mathematics and pure Physics are\nactual and given; for both contain propositions, which are thoroughly\nrecognised as apodeictically certain, partly by mere reason, partly by\ngeneral consent arising from experience, and yet as independent of\nexperience. We have therefore some at least uncontested synthetical\nknowledge a priori, and need not ask whether it be possible, for it is\nactual, but how it is possible, in order that we may deduce from the\nprinciple which makes the given cognitions possible the possibility of\nall the rest.\n\nThe General Problem: How is Cognition from Pure Reason Possible?\n\n\u00a7 5. We have above learned the significant distinction between\nanalytical and synthetical judgments. The possibility of analytical\npropositions was easily comprehended, being entirely founded on the\nlaw of Contradiction. The possibility of synthetical a posteriori\njudgments, of those which are gathered from experience, also requires\nno particular explanation; for experience is nothing but a continual\nsynthesis of perceptions. There remain therefore only synthetical\npropositions a priori, of which the possibility must be sought or\ninvestigated, because they must depend upon other principles than the\nlaw of contradiction.\n\nBut here we need not first establish the possibility of such\npropositions so as to ask whether they are possible. For there are\nenough of them which indeed are of undoubted certainty, and as our\npresent method is analytical, we shall start from the fact, that such\nsynthetical but purely rational cognition actually exists; but we must\nnow inquire into the reason of this possibility, and ask, how such\ncognition is possible, in order that we may from the principles of its\npossibility be enabled to determine the conditions of its use, its\nsphere and its limits. The proper problem upon which all depends, when\nexpressed with scholastic precision, is therefore:\n\nHow are Synthetic Propositions a priori possible?\n\nFor the sake of popularity I have above expressed this problem\nsomewhat differently, as an inquiry into purely rational cognition,\nwhich I could do for once without detriment to the desired\ncomprehension, because, as we have only to do here with metaphysics\nand its sources, the reader will, I hope, after the fore going\nremarks, keep in mind that when we speak of purely rational cognition,\nwe do not mean analytical, but synthetical cognition.{9}\n\n===================================\n{9} It is unavoidable that as knowledge advances, certain expressions\nwhich have become classical, after having been used since the infancy\nof science, will be found inadequate and unsuitable, and a newer and\nmore appropriate application of the terms will give rise to confusion.\n[This is the case with the term \"analytical.\"] The analytical method,\nso far as it is opposed to the synthetical, is very different from\nthat which constitutes the essence of analytical propositions: it\nsignifies only that we start from what is sought, as if it were given,\nand ascend to the only conditions under which it is possible. In this\nmethod we often use nothing but synthetical propositions, as in\nmathematical analysis, and it were better to term it the regressive\nmethod, in contradistinction to the synthetic or progressive. A\nprincipal part of Logic too is distinguished by the name of Analytics,\nwhich here signifies the logic of truth in contrast to Dialectics,\nwithout considering whether the cognitions belonging to it are\nanalytical or synthetical.\n===================================\n\nMetaphysics stands or falls with the solution of this problem: its\nvery existence depends upon it. Let any one make metaphysical\nassertions with ever so much plausibility, let him overwhelm us with\nconclusions, if he has not previously proved able to answer this\nquestion satisfactorily, I have a right to say: this is all vain\nbaseless philosophy and false wisdom. You speak through pure reason,\nand claim, as it were to create cognitions a priori by not only\ndissecting given concepts, but also by asserting connexions which do\nnot rest upon the law of contradiction, and which you believe you\nconceive quite independently of all experience; how do you arrive at\nthis, and how will you justify your pretensions? An appeal to the\nconsent of the common sense of mankind cannot be allowed; for that is\na witness whose authority depends merely upon rumor. Says Horace:\n\n\"Quodcunque ostendis mihi sic, incredulus odi.\"\n\n\"To all that which thou provest me thus, I refuse to give credence.\"\n\nThe answer to this question, though indispensable, is difficult; and\nthough the principal reason that it was not made long ago is, that the\npossibility of the question never occurred to anybody, there is yet\nanother reason, which is this that a satisfactory answer to this one\nquestion requires a much more persistent, profound, and painstaking\nreflexion, than the most diffuse work on Metaphysics, which on its\nfirst appearance promised immortality to its author. And every\nintelligent reader, when he carefully reflects what this problem\nrequires, must at first be struck with its difficulty, and would\nregard it as insoluble and even impossible, did there not actually\nexist pure synthetical cognitions a priori. This actually happened to\nDavid Hume, though he did not conceive the question in its entire\nuniversality as is done here, and as must be done, should the answer\nbe decisive for all Metaphysics. For how is it possible, says that\nacute man, that when a concept is given me, I can go beyond it and\nconnect with it another, which is not contained in it, in such a\nmanner as if the latter necessarily belonged to the former? Nothing\nbut experience can furnish us with such connexions (thus he concluded\nfrom the difficulty which he took to be an impossibility), and all\nthat vaunted necessity, or, what is the same thing, all cognition\nassumed to be a priori, is nothing but a long habit of accepting\nsomething as true, and hence of mistaking subjective necessity for\nobjective.\n\nShould my reader complain of the difficulty and the trouble which I\noccasion him in the solution of this problem, he is at liberty to\nsolve it himself in an easier way. Perhaps he will then feel under\nobligation to the person who has undertaken for him a labor of so\nprofound research, and will rather be surprised at the facility with\nwhich, considering the nature of the subject, the solution has been\nattained. Yet it has cost years of work to solve the problem in its\nwhole universality (using the term in the mathematical sense, viz.,\nfor that which is sufficient for all cases), and finally to exhibit it\nin the analytical form, as the reader finds it here.\n\nAll metaphysicians are therefore solemnly and legally suspended from\ntheir occupations till they shall have answered in a satisfactory\nmanner the question, \"How are synthetic cognitions a priori possible?\"\nFor the answer contains which they must show when they have anything\nto offer in the name of pure reason. But if they do not possess these\ncredentials, they can expect nothing else of reasonable people, who\nhave been deceived so often, than to be dismissed without further ado.\n\nIf they on the other hand desire to carry on their business, not as a\nscience, but as an art of wholesome oratory suited to the common sense\nof man, they cannot in justice be prevented. They will then speak the\nmodest language of a rational belief, they will grant that they are\nnot allowed even to conjecture, far less to know, anything which lies\nbeyond the bounds of all possible experience, but only to assume (not\nfor speculative use, which they must abandon, but for practical\npurposes only) the existence of something that is possible and even\nindispensable for the guidance of the understanding and of the will in\nlife. In this manner alone can they be called useful and wise men, and\nthe more so as they renounce the title of metaphysicians; for the\nlatter profess to be speculative philosophers, and since, when\njudgments a priori are under discussion, poor probabilities cannot be\nadmitted (for what is declared to be known a priori is thereby\nannounced as necessary), such men cannot be permitted to play with\nconjectures, but their assertions must be either science, or are worth\nnothing at all.\n\nIt may be said, that the entire transcendental philosophy, which\nnecessarily precedes all metaphysics, is nothing but the complete\nsolution of the problem here propounded, in systematical order and\ncompleteness, and hitherto we have never had any transcendental\nphilosophy; for what goes by its name is properly a part of\nmetaphysics, whereas the former science is intended first to\nconstitute the possibility of the latter, and must therefore precede\nall metaphysics. And it is not surprising that when a whole science,\ndeprived of all help from other sciences, and consequently in itself\nquite new, is required to answer a single question satisfactorily, we\nshould find the answer troublesome and difficult, nay even shrouded in\nobscurity.\n\nAs we now proceed to this solution according to the analytical method,\nin which we assume that such cognitions from pure reasons actually\nexist, we can only appeal to two sciences of theoretical cognition\n(which alone is under consideration here), pure mathematics and pure\nnatural science (physics). For these alone can exhibit to us objects\nin a definite and actualisable form (in der Anschauung), and\nconsequently (if there should occur in them a cognition a priori) can\nshow the truth or conformity of the cognition to the object in\nconcreto, that is, its actuality, from which we could proceed to the\nreason of its possibility by the analytic method. This facilitates our\nwork greatly for here universal considerations are not only applied to\nfacts, but even start from them, while in a synthetic procedure they\nmust strictly be derived in abstracto from concepts.\n\nBut, in order to rise from these actual and at the same time\nwell-grounded pure cognitions a priori to such a possible cognition of\nthe same as we are seeking, viz., to metaphysics as a science, we must\ncomprehend that which occasions it, I mean the mere natural, though in\nspite of its truth not unsuspected, cognition a priori which lies at\nthe bottom of that science, the elaboration of which without any\ncritical investigation of its possibility is commonly called\nmetaphysics. In a word, we must comprehend the natural conditions of\nsuch a science as a part of our inquiry, and thus the transcendental\nproblem will be gradually answered by a division into four questions:\n\n1. How is pure mathematics possible?\n2. How is pure natural science possible?\n3. How is metaphysics in general possible?\n4. How is metaphysics as a science possible?\n\nIt may be seen that the solution of these problems, though chiefly\ndesigned to exhibit the essential matter of the Critique, has yet\nsomething peculiar, which for itself alone deserves attention. This is\nthe search for the sources of given sciences in reason itself, so that\nits faculty of knowing something a priori may by its own deeds be\ninvestigated and measured. By this procedure these sciences gain, if\nnot with regard to their contents, yet as to their proper use, and\nwhile they throw light on the higher question concerning their common\norigin, they give, at the same time, an occasion better to explain\ntheir own nature.\n\nFIRST PART OF THE TRANSCENDENTAL PROBLEM.\n\nHOW IS PURE MATHEMATICS POSSIBLE?\n\n\u00a7\u00a06.\n\nHere is a great and established branch of knowledge, encompassing even\nnow a wonderfully large domain and promising an unlimited extension in\nthe future. Yet it carries with it thoroughly apodeictical certainty,\ni.e., absolute necessity, which therefore rests upon no empirical\ngrounds. Consequently it is a pure product of reason, and moreover is\nthoroughly synthetical. [Here the question arises:]\n\n\"How then is it possible for human reason to produce a cognition of\nthis nature entirely a priori?\"\n\nDoes not this faculty [which produces mathematics], as it neither is\nnor can be based upon experience, presuppose some ground of cognition\na priori, which lies deeply hidden, but which might reveal itself by\nthese its effects, if their first beginnings were but diligently\nferreted out?\n\n\u00a7 7. But we find that all mathematical cognition has this\npeculiarity: it must first exhibit its concept in a visual form\n(Anschauung) and indeed a priori, therefore in a visual form which is\nnot empirical, but pure. Without this mathematics cannot take a single\nstep; hence its judgments are always visual, viz., \"intuitive\";\nwhereas philosophy must be satisfied with discursive judgments from\nmere concepts, and though it may illustrate its doctrines through a\nvisual figure, can never derive them from it. This observation on the\nnature of mathematics gives us a clue to the first and highest\ncondition of its possibility, which is, that some non-sensuous\nvisualisation (called pure intuition, or reine Anschauung) must form\nits basis, in which all its concepts can be exhibited or constructed,\nin concreto and yet a priori. If we can find out this pure intuition\nand its possibility, we may thence easily explain how synthetical\npropositions a priori are possible in pure mathematics, and\nconsequently how this science itself is possible. Empirical intuition\n[viz., sense-perception] enables us without difficulty to enlarge the\nconcept which we frame of an object of intuition [or\nsense-perception], by new predicates, which intuition [i.e.,\nsense-perception] itself presents synthetically in experience. Pure\nintuition [viz., the visualisation of forms in our imagination, from\nwhich every thing sensual, i.e., every thought of material qualities,\nis excluded] does so likewise, only with this difference, that in the\nlatter case the synthetical judgment is a priori certain and\napodeictical, in the former, only a posteriori and empirically\ncertain; because this latter contains only that which occurs in\ncontingent empirical intuition, but the former, that which must\nnecessarily be discovered in pure intuition. Here intuition, being an\nintuition a priori, is before all experience, viz., before any\nperception of particular objects, inseparably conjoined with its\nconcept.\n\n\u00a7 8. But with this step our perplexity seems rather to increase than\nto lessen. For the question now is, \"How is it possible to intuite [in\na visual form] anything a priori?\" An intuition [viz., a visual\nsense-perception] is such a representation as immediately depends upon\nthe presence of the object. Hence it seems impossible to intuite from\nthe outset a priori, because intuition would in that event take place\nwithout either a former or a present object to refer to, and by\nconsequence could not be intuition. Concepts indeed are such, that we\ncan easily form some of them a priori, viz., such as contain nothing\nbut the thought of an object in general; and we need not find\nourselves in an immediate relation to the object. Take, for instance,\nthe concepts of Quantity, of Cause, etc. But even these require, in\norder to make them under stood, a certain concrete use\u2014that is, an\napplication to some sense-experience (Anschauung), by which an object\nof them is given us. But how can the intuition of the object [its\nvisualisation] precede the object itself?\n\n\u00a7 9. If our intuition [i.e., our sense-experience] were perforce of\nsuch a nature as to represent things as they are in themselves, there\nwould not be any intuition a priori, but intuition would be always\nempirical. For I can only know what is contained in the object in\nitself when it is present and given to me. It is indeed even then\nincomprehensible how the visualising (Anschauung) of a present thing\nshould make me know this thing as it is in itself, as its properties\ncannot migrate into my faculty of representation. But even granting\nthis possibility, a visualising of that sort would not take place a\npriori, that is, before the object were presented to me; for without\nthis latter fact no reason of a relation between my representation and\nthe object can be imagined, unless it depend upon a direct\ninspiration.\n\nTherefore in one way only can my intuition (Anschauung) anticipate the\nactuality of the object, and be a cognition a priori, viz.: if my\nintuition contains nothing but the form of sensibility, antedating in\nmy subjectivity all the actual impressions through which I am affected\nby objects.\n\nFor that objects of sense can only be intuited according to this form\nof sensibility I can know a priori. Hence it follows: that\npropositions, which concern this form of sensuous intuition only, are\npossible and valid for objects of the senses; as also, conversely,\nthat intuitions which are possible a priori can never concern any\nother things than objects of our senses.{10}\n\n===================================\n{10} This whole paragraph (\u00a7 9) will be better understood when compared\nwith Remark I., following this section, appearing in the present\nedition on page 40.\u2014Ed.\n===================================\n\n\u00a7\u00a010. Accordingly, it is only the form of the sensuous intuition by\nwhich we can intuite things a priori, but by which we can know objects\nonly as they appear to us (to our senses), not as they are in\nthemselves; and this assumption is absolutely necessary if synthetical\npropositions a priori be granted as possible, or if, in case they\nactually occur, their possibility is to be comprehended and determined\nbeforehand.\n\nNow, the intuitions which pure mathematics lays at the foundation of\nall its cognitions and judgments which appear at once apodeictic and\nnecessary are Space and Time. For mathematics must first have all its\nconcepts in intuition, and pure mathematics in pure intuition, that\nis, it must construct them. If it proceeded in any other way, it would\nbe impossible to make any headway, for mathematics proceeds, not\nanalytically by dissection of concepts, but synthetically, and if pure\nintuition be wanting, there is nothing in which the matter for\nsynthetical judgments a priori can be given. Geometry is based upon\nthe pure intuition of space. Arithmetic accomplishes its concept of\nnumber by the successive addition of units in time; and pure mechanics\nespecially cannot attain its concepts of motion without employing the\nrepresentation of time. Both representations, however, are only\nintuitions; for if we omit from the empirical intuitions of bodies and\ntheir alterations (motion) everything empirical, or belonging to\nsensation, space and time still remain, which are therefore pure\nintuitions that lie a priori at the basis of the empirical. Hence they\ncan never be omitted, but at the same time, by their being pure\nintuitions a priori, they prove that they are mere forms of our\nsensibility, which must precede all empirical intuition, or perception\nof actual objects, and conformably to which objects can be known a\npriori, but only as they appear to us.\n\n\u00a7 11. The problem of the present section is therefore solved. Pure\nmathematics, as synthetical cognition a priori, is only possible by\nreferring to no other objects than those of the senses. At the basis\nof their empirical intuition lies a pure intuition (of space and of\ntime) which is a priori. This is possible, because the latter\nintuition is nothing but the mere form of sensibility, which precedes\nthe actual appearance of the objects, in that it, in fact, makes them\npossible. Yet this faculty of intuiting a priori affects not the\nmatter of the phenomenon (that is, the sense-element in it, for this\nconstitutes that which is empirical), but its form, viz., space and\ntime. Should any man venture to doubt that these are determinations\nadhering not to things in themselves, but to their relation to our\nsensibility, I should be glad to know how it can be possible to know\nthe constitution of things a priori, viz., before we have any\nacquaintance with them and before they are presented to us. Such,\nhowever, is the case with space and time. But this is quite\ncomprehensible as soon as both count for nothing more than formal\nconditions of our sensibility, while the objects count merely as\nphenomena; for then the form of the phenomenon, i.e., pure intuition,\ncan by all means be represented as proceeding from ourselves, that is,\na priori.\n\n\u00a7 12. In order to add something by way of illustration and\nconfirmation, we need only watch the ordinary and necessary procedure\nof geometers. All proofs of the complete congruence of two given\nfigures (where the one can in every respect be substituted for the\nother) come ultimately to this that they may be made to coincide;\nwhich is evidently nothing else than a synthetical proposition resting\nupon immediate intuition, and this intuition must be pure, or given a\npriori, otherwise the proposition could not rank as apodeictically\ncertain, but would have empirical certainty only. In that case, it\ncould only be said that it is always found to be so, and holds good\nonly as far as our perception reaches. That everywhere space (which\n[in its entirety] is itself no longer the boundary of another space)\nhas three dimensions, and that space cannot in any way have more, is\nbased on the proposition that not more than three lines can intersect\nat right angles in one point; but this proposition cannot by any means\nbe shown from concepts, but rests immediately on intuition, and indeed\non pure and a priori intuition, because it is apodeictically certain.\nThat we can require a line to be drawn to infinity (in indefinitum),\nor that a series of changes (for example, spaces traversed by motion)\nshall be infinitely continued, presupposes a representation of space\nand time, which can only attach to intuition, namely, so far as it in\nitself is bounded by nothing, for from concepts it could never be\ninferred. Consequently, the basis of mathematics actually are pure\nintuitions, which make its synthetical and apodeictically valid\npropositions possible. Hence our transcendental deduction of the\nnotions of space and of time explains at the same time the possibility\nof pure mathematics. Without some such deduction its truth may be\ngranted, but its existence could by no means be understood, and we\nmust assume \"that everything which can be given to our senses (to the\nexternal senses in space, to the internal one in time) is intuited by\nus as it appears to us, not as it is in itself.\"\n\n\u00a7 13. Those who cannot yet rid themselves of the notion that space\nand time are actual qualities inhering in things in themselves, may\nexercise their acumen on the following paradox. When they have in vain\nattempted its solution, and are free from prejudices at least for a\nfew moments, they will suspect that the degradation of space and of\ntime to mere forms of our sensuous intuition may perhaps be well\nfounded.\n\nIf two things are quite equal in all respects as much as can be\nascertained by all means possible, quantitatively and qualitatively,\nit must follow, that the one can in all cases and under all\ncircumstances replace the other, and this substitution would not\noccasion the least perceptible difference. This in fact is true of\nplane figures in geometry; but some spherical figures exhibit,\nnotwithstanding a complete internal agreement, such a contrast in\ntheir external relation, that the one figure cannot possibly be put in\nthe place of the other. For instance, two spherical triangles on\nopposite hemispheres, which have an arc of the equator as their common\nbase, may be quite equal, both as regards sides and angles, so that\nnothing is to be found in either, if it be described for itself alone\nand completed, that would not equally be applicable to both; and yet\nthe one cannot be put in the place of the other (being situated upon\nthe opposite hemisphere). Here then is an internal difference between\nthe two triangles, which difference our understanding cannot describe\nas internal, and which only manifests itself by external relations in\nspace.\n\nBut I shall adduce examples, taken from common life, that are more\nobvious still.\n\nWhat can be more similar in every respect and in every part more alike\nto my hand and to my ear, than their images in a mirror? And yet I\ncannot put such a hand as is seen in the glass in the place of its\narchetype; for if this is a right hand, that in the glass is a left\none, and the image or reflexion of the right ear is a left one which\nnever can serve as a substitute for the other. There are in this case\nno internal differences which our understanding could determine by\nthinking alone. Yet the differences are internal as the senses teach,\nfor, notwithstanding their complete equality and similarity, the left\nhand cannot be enclosed in the same bounds as the right one (they are\nnot congruent); the glove of one hand cannot be used for the other.\nWhat is the solution? These objects are not representations of things\nas they are in themselves, and as the pure understanding would cognise\nthem, but sensuous intuitions, that is, appearances, the possibility\nof which rests upon the relation of certain things unknown in\nthemselves to something else, viz., to our sensibility. Space is the\nform of the external intuition of this sensibility, and the internal\ndetermination of every space is only possible by the determination of\nits external relation to the whole space, of which it is a part (in\nother words, by its relation to the external sense). That is to say,\nthe part is only possible through the whole, which is never the case\nwith things in themselves, as objects of the mere understanding, but\nwith appearances only. Hence the difference between similar and equal\nthings, which are yet not congruent (for instance, two symmetric\nhelices), cannot be made intelligible by any concept, but only by the\nrelation to the right and the left hands which immediately refers to\nintuition.\n\nRemark I.\n\nPure Mathematics, and especially pure geometry, can only have\nobjective reality on condition that they refer to objects of sense.\nBut in regard to the latter the principle holds good, that our sense\nrepresentation is not a representation of things in themselves, but of\nthe way in which they appear to us. Hence it follows, that the\npropositions of geometry are not the results of a mere creation of our\npoetic imagination, and that therefore they cannot be referred with\nassurance to actual objects; but rather that they are necessarily\nvalid of space, and consequently of all that may be found in space,\nbecause space is nothing else than the form of all external\nappearances, and it is this form alone in which objects of sense can\nbe given. Sensibility, the form of which is the basis of geometry, is\nthat upon which the possibility of external appearance depends.\nTherefore these appearances can never contain anything but what\ngeometry prescribes to them.\n\nIt would be quite otherwise if the senses were so constituted as to\nrepresent objects as they are in themselves. For then it would not by\nany means follow from the conception of space, which with all its\nproperties serves to the geometer as an a priori foundation, together\nwith what is thence inferred, must be so in nature. The space of the\ngeometer would be considered a mere fiction, and it would not be\ncredited with objective validity, because we cannot see how things\nmust of necessity agree with an image of them, which we make\nspontaneously and previous to our acquaintance with them. But if this\nimage, or rather this formal intuition, is the essential property of\nour sensibility, by means of which alone objects are given to us, and\nif this sensibility represents not things in themselves, but their\nappearances: we shall easily comprehend, and at the same time\nindisputably prove, that all external objects of our world of sense\nmust necessarily coincide in the most rigorous way with the\npropositions of geometry; because sensibility by means of its form of\nexternal intuition, viz., by space, the same with which the geometer\nis occupied, makes those objects at all possible as mere appearances.\n\nIt will always remain a remarkable phenomenon in the history of\nphilosophy, that there was a time, when even mathematicians, who at\nthe same time were philosophers, began to doubt, not of the accuracy\nof their geometrical propositions so far as they concerned space, but\nof their objective validity and the applicability of this concept\nitself, and of all its corollaries, to nature. They showed much\nconcern whether a line in nature might not consist of physical points,\nand consequently that true space in the object might consist of simple\n[discrete] parts, while the space which the geometer has in his mind\n[being continuous] cannot be such. They did not recognise that this\nmental space renders possible the physical space, i.e., the extension\nof matter; that this pure space is not at all a quality of things in\nthemselves, but a form of our sensuous faculty of representation; and\nthat all objects in space are mere appearances, i.e., not things in\nthemselves but representations of our sensuous intuition. But such is\nthe case, for the space of the geometer is exactly the form of\nsensuous intuition which we find a priori in us, and contains the\nground of the possibility of all external appearances (according to\ntheir form), and the latter must necessarily and most rigidly agree\nwith the propositions of the geometer, which he draws not from any\nfictitious concept, but from the subjective basis of all external\nphenomena, which is sensibility itself. In this and no other way can\ngeometry be made secure as to the undoubted objective reality of its\npropositions against all the intrigues of a shallow Metaphysics, which\nis surprised at them [the geometrical propositions], because it has\nnot traced them to the sources of their concepts.\n\nRemark II.\n\nWhatever is given us as object, must be given us in intuition. All our\nintuition however takes place by means of the senses only; the\nunderstanding intuites nothing, but only reflects. And as we have just\nshown that the senses never and in no manner enable us to know things\nin themselves, but only their appearances, which are mere\nrepresentations of the sensibility, we conclude that 'all bodies,\ntogether with the space in which they are, must be considered nothing\nbut mere representations in us, and exist nowhere but in our\nthoughts.' You will say: Is not this manifest idealism?\n\nIdealism consists in the assertion, that there are none but thinking\nbeings, all other things, which we think are perceived in intuition,\nbeing nothing but representations in the thinking beings, to which no\nobject external to them corresponds in fact. Whereas I say, that\nthings as objects of our senses existing outside us are given, but we\nknow nothing of what they may be in themselves, knowing only their\nappearances, i.e., the representations which they cause in us by\naffecting our senses. Consequently I grant by all means that there are\nbodies without us, that is, things which, though quite unknown to us\nas to what they are in themselves, we yet know by the representations\nwhich their influence on our sensibility procures us, and which we\ncall bodies, a term signifying merely the appearance of the thing\nwhich is unknown to us, but not therefore less actual. Can this be\ntermed idealism? It is the very contrary.\n\nLong before Locke's time, but assuredly since him, it has been\ngenerally assumed and granted without detriment to the actual\nexistence of external things, that many of their predicates may be\nsaid to belong not to the things in themselves, but to their\nappearances, and to have no proper existence outside our\nrepresentation. Heat, color, and taste, for instance, are of this\nkind. Now, if I go farther, and for weighty reasons rank as mere\nappearances the remaining qualities of bodies also, which are called\nprimary, such as extension, place, and in general space, with all that\nwhich belongs to it (impenetrability or materiality, space, etc.)\u2014no\none in the least can adduce the reason of its being inadmissible. As\nlittle as the man who admits colors not to be properties of the object\nin itself, but only as modifications of the sense of sight, should on\nthat account be called an idealist, so little can my system be named\nidealistic, merely because I find that more, nay,\n\nAll the properties which constitute the intuition of a body belong\nmerely to its appearance.\n\nThe existence of the thing that appears is thereby not destroyed, as\nin genuine idealism, but it is only shown, that we cannot possibly\nknow it by the senses as it is in itself.\n\nI should be glad to know what my assertions must be in order to avoid\nall idealism. Undoubtedly, I should say, that the representation of\nspace is not only perfectly conformable to the relation which our\nsensibility has to objects\u2014that I have said\u2014but that it is quite\nsimilar to the object,\u2014an assertion in which I can find as little\nmeaning as if I said that the sensation of red has a similarity to the\nproperty of vermilion, which in me excites this sensation.\n\nRemark III.\n\nHence we may at once dismiss an easily foreseen but futile objection,\n\"that by admitting the ideality of space and of time the whole\nsensible world would be turned into mere sham.\" At first all\nphilosophical insight into the nature of sensuous cognition was\nspoiled, by making the sensibility merely a confused mode of\nrepresentation, according to which we still know things as they are,\nbut without being able to reduce everything in this our representation\nto a clear consciousness; whereas proof is offered by us that\nsensibility consists, not in this logical distinction of clearness and\nobscurity, but in the genetical one of the origin of cognition itself.\nFor sensuous perception represents things not at all as they are, but\nonly the mode in which they affect our senses, and consequently by\nsensuous perception appearances only and not things themselves are\ngiven to the understanding for reflexion. After this necessary\ncorrective, an objection rises from an unpardonable and almost\nintentional misconception, as if my doctrine turned all the things of\nthe world of sense into mere illusion.\n\nWhen an appearance is given us, we are still quite free as to how we\nshould judge the matter. The appearance depends upon the senses, but\nthe judgment upon the understanding, and the only question is, whether\nin the determination of the object there is truth or not. But the\ndifference between truth and dreaming is not ascertained by the nature\nof the representations, which are referred to objects (for they are\nthe same in both cases), but by their connexion according to those\nrules, which determine the coherence of the representations in the\nconcept of an object, and by ascertaining whether they can subsist\ntogether in experience or not. And it is not the fault of the\nappearances if our cognition takes illusion for truth, i.e., if the\nintuition, by which an object is given us, is considered a concept of\nthe thing or of its existence also, which the understanding can only\nthink. The senses represent to us the paths of the planets as now\nprogressive, now retrogressive, and herein is neither falsehood nor\ntruth, because as long as we hold this path to be nothing but\nappearance, we do not judge of the objective nature of their motion.\nBut as a false judgment may easily arise when the understanding is not\non its guard against this subjective mode of representation being\nconsidered objective, we say they appear to move backward; it is not\nthe senses however which must be charged with the illusion, but the\nunderstanding, whose province alone it is to give an objective\njudgment on appearances.\n\nThus, even if we did not at all reflect on the origin of our\nrepresentations, whenever we connect our intuitions of sense (whatever\nthey may contain), in space and in time, according to the rules of the\ncoherence of all cognition in experience, illusion or truth will arise\naccording as we are negligent or careful. It is merely a question of\nthe use of sensuous representations in the understanding, and not of\ntheir origin. In the same way, if I consider all the representations\nof the senses, together with their form, space and time, to be nothing\nbut appearances, and space and time to be a mere form of the\nsensibility, which is not to be met with in objects out of it, and if\nI make use of these representations in reference to possible\nexperience only, there is nothing in my regarding them as appearances\nthat can lead astray or cause illusion. For all that they can\ncorrectly cohere according to rules of truth in experience. Thus all\nthe propositions of geometry hold good of space as well as of all the\nobjects of the senses, consequently of all possible experience,\nwhether I consider space as a mere form of the sensibility, or as\nsomething cleaving to the things themselves. In the former case\nhowever I comprehend how I can know a priori these propositions\nconcerning all the objects of external intuition. Otherwise,\neverything else as regards all possible experience remains just as if\nI had not departed from the vulgar view.\n\nBut if I venture to go beyond all possible experience with my notions\nof space and time, which I cannot refrain from doing if I proclaim\nthem qualities inherent in things in themselves (for what should\nprevent me from letting them hold good of the same things, even though\nmy senses might be different, and unsuited to them?), then a grave\nerror may arise due to illusion, for thus I would proclaim to be\nuniversally valid what is merely a subjective condition of the\nintuition of things and sure only for all objects of sense, viz., for\nall possible experience; I would refer this condition to things in\nthemselves, and do not limit it to the conditions of experience.\n\nMy doctrine of the ideality of space and of time, therefore, far from\nreducing the whole sensible world to mere illusion, is the only means\nof securing the application of one of the most important cognitions\n(that which mathematics propounds a priori) to actual objects, and of\npreventing its being regarded as mere illusion. For without this\nobservation it would be quite impossible to make out whether the\nintuitions of space and time, which we borrow from no experience, and\nwhich yet lie in our representation a priori, are not mere phantasms\nof our brain, to which objects do not correspond, at least not\nadequately, and consequently, whether we have been able to show its\nunquestionable validity with regard to all the objects of the sensible\nworld just because they are mere appearances.\n\nSecondly, though these my principles make appearances of the\nrepresentations of the senses, they are so far from turning the truth\nof experience into mere illusion, that they are rather the only means\nof preventing the transcendental illusion, by which metaphysics has\nhitherto been deceived, leading to the childish endeavor of catching\nat bubbles, because appearances, which are mere representations, were\ntaken for things in themselves. Here originated the remarkable event\nof the antimony of Reason which I shall mention by and by, and which\nis destroyed by the single observation, that appearance, as long as it\nis employed in experience, produces truth, but the moment it\ntransgresses the bounds of experience, and consequently becomes\ntranscendent, produces nothing but illusion.\n\nInasmuch, therefore, as I leave to things as we obtain them by the\nsenses their actuality, and only limit our sensuous intuition of these\nthings to this, that they represent in no respect, not even in the\npure intuitions of space and of time, anything more than mere\nappearance of those things, but never their constitution in\nthemselves, this is not a sweeping illusion invented for nature by me.\nMy protestation too against all charges of idealism is so valid and\nclear as even to seem superfluous, were there not incompetent judges,\nwho, while they would have an old name for every deviation from their\nperverse though common opinion, and never judge of the spirit of\nphilosophic nomenclature, but cling to the letter only, are ready to\nput their own conceits in the place of well-defined notions, and\nthereby deform and distort them. I have myself given this my theory\nthe name of transcendental idealism, but that cannot authorise any one\nto confound it either with the empirical idealism of Descartes,\n(indeed, his was only an insoluble problem, owing to which he thought\nevery one at liberty to deny the existence of the corporeal world,\nbecause it could never be proved satisfactorily), or with the mystical\nand visionary idealism of Berkeley, against which and other similar\nphantasms our Critique contains the proper antidote. My idealism\nconcerns not the existence of things (the doubting of which, however,\nconstitutes idealism in the ordinary sense), since it never came into\nmy head to doubt it, but it concerns the sensuous representation of\nthings, to which space and time especially belong. Of these [viz.,\nspace and time], consequently of all appearances in general, I have\nonly shown, that they are neither things (but mere modes of\nrepresentation), nor determinations belonging to things in themselves.\nBut the word \"transcendental,\" which with me means a reference of our\ncognition, i.e., not to things, but only to the cognitive faculty, was\nmeant to obviate this misconception. Yet rather than give further\noccasion to it by this word, I now retract it, and desire this\nidealism of mine to be called critical. But if it be really an\nobjectionable idealism to convert actual things (not appearances) into\nmere representations, by what name shall we call him who conversely\nchanges mere representations to things? It may, I think, be called\n\"dreaming idealism,\" in contradistinction to the former, which may be\ncalled \"visionary,\" both of which are to be refuted by my\ntranscendental, or, better, critical idealism.\n\nSECOND PART OF THE TRANSCENDENTAL PROBLEM.\n\nHOW IS THE SCIENCE OF NATURE POSSIBLE?\n\n\u00a7 14.\n\nNature is the existence of things, so far as it is determined\naccording to universal laws. Should nature signify the existence of\nthings in themselves, we could never cognise it either a priori or a\nposteriori. Not a priori, for how can we know what belongs to things\nin themselves, since this never can be done by the dissection of our\nconcepts (in analytical judgments)? We do not want to know what is\ncontained in our concept of a thing (for the [concept describes what]\nbelongs to its logical being), but what is in the actuality of the\nthing superadded to our concept, and by what the thing itself is\ndetermined in its existence outside the concept. Our understanding,\nand the conditions on which alone it can connect the determinations of\nthings in their existence, do not prescribe any rule to things\nthemselves; these do not conform to our understanding, but it must\nconform itself to them; they must therefore be first given us in order\nto gather these determinations from them, wherefore they would not be\ncognised a priori.\n\nA cognition of the nature of things in themselves a posteriori would\nbe equally impossible. For, if experience is to teach us laws, to\nwhich the existence of things is subject, these laws, if they regard\nthings in themselves, must belong to them of necessity even outside\nour experience. But experience teaches us what exists and how it\nexists, but never that it must necessarily exist so and not otherwise.\nExperience therefore can never teach us the nature of things in\nthemselves.\n\n\u00a7 15. We nevertheless actually possess a pure science of nature in\nwhich are propounded, a priori and with all the necessity requisite to\napodeictical propositions, laws to which nature is subject. I need\nonly call to witness that propaedeutic of natural science which, under\nthe title of the universal Science of Nature, precedes all Physics\n(which is founded upon empirical principles). In it we have\nMathematics applied to appearance, and also merely discursive\nprinciples (or those derived from concepts), which constitute the\nphilosophical part of the pure cognition of nature. But there are\nseveral things in it, which are not quite pure and independent of\nempirical sources: such as the concept of motion, that of\nimpenetrability (upon which the empirical concept of matter rests),\nthat of inertia, and many others, which prevent its being called a\nperfectly pure science of nature. Besides, it only refers to objects\nof the external sense, and therefore does not give an example of a\nuniversal science of nature, in the strict sense, for such a science\nmust reduce nature in general, whether it regards the object of the\nexternal or that of the internal sense (the object of Physics as well\nas Psychology), to universal laws. But among the principles of this\nuniversal physics there are a few which actually have the required\nuniversality; for instance, the propositions that \"substance is\npermanent,\" and that \"every event is determined by a cause according\nto constant laws,\" etc. These are actually universal laws of nature,\nwhich subsist completely a priori. There is then in fact a pure\nscience of nature, and the question arises, How is it possible?\n\n\u00a7 16. The word \"nature\" assumes yet another meaning, which determines\nthe object, whereas in the former sense it only denotes the conformity\nto law [Gesetzm\u00e4ssigkeit] of the determinations of the existence of\nthings generally. If we consider it materialiter (i.e., in the matter\nthat forms its objects) \"nature is the complex of all the objects of\nexperience.\" And with this only are we now concerned, for besides,\nthings which can never be objects of experience, if they must be\ncognised as to their nature, would oblige us to have recourse to\nconcepts whose meaning could never be given in concreto (by any\nexample of possible experience). Consequently we must form for\nourselves a list of concepts of their nature, the reality whereof\n(i.e., whether they actually refer to objects, or are mere creations\nof thought) could never be determined. The cognition of what cannot be\nan object of experience would be hyperphysical, and with things\nhyperphysical we are here not concerned, but only with the cognition\nof nature, the actuality of which can be confirmed by experience,\nthough it [the cognition of nature] is possible a priori and precedes\nall experience.\n\n\u00a7 17. The formal [aspect] of nature in this narrower sense is\ntherefore the conformity to law of all the objects of experience, and\nso far as it is cognised a priori, their necessary conformity. But it\nhas just been shown that the laws of nature can never be cognised a\npriori in objects so far as they are considered not in reference to\npossible experience, but as things in themselves. And our inquiry here\nextends not to things in themselves (the properties of which we pass\nby), but to things as objects of possible experience, and the complex\nof these is what we properly designate as nature. And now I ask, when\nthe possibility of a cognition of nature a priori is in question,\nwhether it is better to arrange the problem thus: How can we cognise a\npriori that things as objects of experience necessarily conform to\nlaw? or thus: How is it possible to cognise a priori the necessary\nconformity to law of experience itself as regards all its objects\ngenerally?\n\nClosely considered, the solution of the problem, represented in either\nway, amounts, with regard to the pure cognition of nature (which is\nthe point of the question at issue), entirely to the same thing. For\nthe subjective laws, under which alone an empirical cognition of\nthings is possible, hold good of these things, as Objects of possible\nexperience (not as things in themselves, which are not considered\nhere). Either of the following statements means quite the same:\n\nA judgment of observation can never rank as experience, without the\nlaw, that \"whenever an event is observed, it is always referred to\nsome antecedent, which it follows according to a universal rule.\"\n\n\"Everything, of which experience teaches that it happens, must have a\ncause.\"\n\nIt is, however, more commendable to choose the first formula. For we\ncan a priori and previous to all given objects have a cognition of\nthose conditions, on which alone experience is possible, but never of\nthe laws to which things may in themselves be subject, without\nreference to possible experience. We cannot therefore study the nature\nof things a priori otherwise than by investigating the conditions and\nthe universal (though subjective) laws, under which alone such a\ncognition as experience (as to mere form) is possible, and we\ndetermine accordingly the possibility of things, as objects of\nexperience. For if I should choose the second formula, and seek the\nconditions a priori, on which nature as an object of experience is\npossible, I might easily fall into error, and fancy that I was\nspeaking of nature as a thing in itself, and then move round in\nendless circles, in a vain search for laws concerning things of which\nnothing is given me.\n\nAccordingly we shall here be concerned with experience only, and the\nuniversal conditions of its possibility which are given a priori.\nThence we shall determine nature as the whole object of all possible\nexperience. I think it will be understood that I here do not mean the\nrules of the observation of a nature that is already given, for these\nalready presuppose experience. I do not mean how (through experience)\nwe can study the laws of nature; for these would not then be laws a\npriori, and would yield us no pure science of nature; but [I mean to\nask] how the conditions a priori of the possibility of experience are\nat the same time the sources from which all the universal laws of\nnature must be derived.\n\n\u00a7 18. In the first place we must state that, while all judgments of\nexperience (Erfahrungsurtheile) are empirical (i.e., have their ground\nin immediate sense perception), vice versa, all empirical judgments\n(empirische Urtheile) are not judgments of experience, but, besides\nthe empirical, and in general besides what is given to the sensuous\nintuition, particular concepts must yet be superadded\u2014concepts which\nhave their origin quite a priori in the pure understanding, and under\nwhich every perception must be first of all subsumed and then by their\nmeans changed into experience.{11}\n\n===================================\n{11} Empirical judgments (empirische Urtheile) are either mere\nstatements of fact, viz., records of a perception, or statements of a\nnatural law, implying a causal connexion between two facts. The former\nKant calls \"judgments of perception\" (Wahrnehmungsurtheile) the latter\n\"judgments of experience\" (Erhfahrungsurtheile).\u2014Ed.\n===================================\n\nEmpirical judgments, so far as they have objective validity, are\njudgments of experience; but those which are only subjectively valid,\nI name mere judgments of perception. The latter require no pure\nconcept of the understanding, but only the logical connexion of\nperception in a thinking subject. But the former always require,\nbesides the representation of the sensuous intuition, particular\nconcepts originally begotten in the understanding, which produce the\nobjective validity of the judgment of experience.\n\nAll our judgments are at first merely judgments of perception; they\nhold good only for us (i.e., for our subject), and we do not till\nafterwards give them a new reference (to an object), and desire that\nthey shall always hold good for us and in the same way for everybody\nelse; for when a judgment agrees with an object, all judgments\nconcerning the same object must likewise agree among themselves, and\nthus the objective validity of the judgment of experience signifies\nnothing else than its necessary universality of application. And\nconversely when we have reason to consider a judgment necessarily\nuniversal (which never depends upon perception, but upon the pure\nconcept of the understanding, under which the perception is subsumed),\nwe must consider it objective also, that is, that it expresses not\nmerely a reference of our perception to a subject, but a quality of\nthe object. For there would be no reason for the judgments of other\nmen necessarily agreeing with mine, if it were not the unity of the\nobject to which they all refer, and with which they accord; hence they\nmust all agree with one another.\n\n\u00a7 19. Therefore objective validity and necessary universality (for\neverybody) are equivalent terms, and though we do not know the object\nin itself, yet when we consider a judgment as universal, and also\nnecessary, we understand it to have objective validity. By this\njudgment we cognise the object (though it remains unknown as it is in\nitself) by the universal and necessary connexion of the given\nperceptions. As this is the case with all objects of sense, judgments\nof experience take their objective validity not from the immediate\ncognition of the object (which is impossible), but from the condition\nof universal validity in empirical judgments, which, as already said,\nnever rests upon empirical, or, in short, sensuous conditions, but\nupon a pure concept of the understanding. The object always remains\nunknown in itself; but when by the concept of the understanding the\nconnexion of the representations of the object, which are given to our\nsensibility, is determined as universally valid, the object is\ndetermined by this relation, and it is the judgment that is objective.\n\nTo illustrate the matter: When we say, \"the room is warm, sugar sweet,\nand wormwood bitter\"{12}\u2014we have only subjectively valid judgments. I\ndo not at all expect that I or any other person shall always find it\nas I now do; each of these sentences only expresses a relation of two\nsensations to the same subject, to myself, and that only in my present\nstate of perception; consequently they are not valid of the object.\nSuch are judgments of perception. Judgments of experience are of quite\na different nature. What experience teaches me under certain\ncircumstances, it must always teach me and everybody; and its validity\nis not limited to the subject nor to its state at a particular time.\nHence I pronounce all such judgments as being objectively valid. For\ninstance, when I say the air is elastic, this judgment is as yet a\njudgment of perception only\u2014I do nothing but refer two of my\nsensations to one another. But, if I would have it called a judgment\nof experience, I require this connexion to stand under a condition,\nwhich makes it universally valid. I desire therefore that I and\neverybody else should always connect necessarily the same perceptions\nunder the same circumstances.\n\n===================================\n{12} I freely grant that these examples do not represent such judgments\nof perception as ever could become judgments of experience, even\nthough a concept of the understanding were superadded, because they\nrefer merely to feeling, which everybody knows to be merely\nsubjective, and which of course can never be attributed to the object,\nand consequently never become objective. I only wished to give here an\nexample of a judgment that is merely subjectively valid, containing no\nground for universal validity, and thereby for a relation to the\nobject. An example of the judgments of perception, which become\njudgments of experience by superadded concepts of the understanding,\nwill be given in the next note.\n===================================\n\n\u00a7 20. We must consequently analyse experience in order to see what is\ncontained in this product of the senses and of the understanding, and\nhow the judgment of experience itself is possible. The foundation is\nthe intuition of which I become conscious, i.e., perception\n(perceptio), which pertains merely to the senses. But in the next\nplace, there are acts of judging (which belong only to the\nunderstanding). But this judging may be twofold\u2014first, I may merely\ncompare perceptions and connect them in a particular state of my\nconsciousness; or, secondly, I may connect them in consciousness\ngenerally. The former judgment is merely a judgment of perception, and\nof subjective validity only: it is merely a connexion of perceptions\nin my mental state, without reference to the object. Hence it is not,\nas is commonly imagined, enough for experience to compare perceptions\nand to connect them in consciousness through judgment; there arises no\nuniversality and necessity, for which alone judgments can become\nobjectively valid and be called experience.\n\nQuite another judgment therefore is required before perception can\nbecome experience. The given intuition must be subsumed under a\nconcept, which determines the form of judging in general relatively to\nthe intuition, connects its empirical consciousness in consciousness\ngenerally, and thereby procures universal validity for empirical\njudgments. A concept of this nature is a pure a priori concept of the\nUnderstanding, which does nothing but determine for an intuition the\ngeneral way in which it can be used for judgments. Let the concept be\nthat of cause, then it determines the intuition which is subsumed\nunder it, e.g., that of air, relative to judgments in general, viz.,\nthe concept of air serves with regard to its expansion in the relation\nof antecedent to consequent in a hypothetical judgment. The concept of\ncause accordingly is a pure concept of the understanding, which is\ntotally disparate from all possible perception, and only serves to\ndetermine the representation subsumed under it, relatively to\njudgments in general, and so to make a universally valid judgment\npossible.\n\nBefore, therefore, a judgment of perception can become a judgment of\nexperience, it is requisite that the perception should be subsumed\nunder some such a concept of the understanding; for instance, air\nranks under the concept of causes, which determines our judgment about\nit in regard to its expansion as hypothetical.{13} Thereby the expansion\nof the air is represented not as merely belonging to the perception of\nthe air in my present state or in several states of mine, or in the\nstate of perception of others, but as belonging to it necessarily. The\njudgment, \"the air is elastic,\" becomes universally valid, and a\njudgment of experience, only by certain judgments preceding it, which\nsubsume the intuition of air under the concept of cause and effect:\nand they thereby determine the perceptions not merely as regards one\nanother in me, but relatively to the form of judging in general, which\nis here hypothetical, and in this way they render the empirical\njudgment universally valid.\n\n===================================\n{13} As an easier example, we may take the following: \"When the sun\nshines on the stone, it grows warm.\" This judgment, however often I\nand others may have perceived it, is a mere judgment of perception,\nand contains no necessity; perceptions are only usually conjoined in\nthis manner. But if I say, \"The sun warms the stone,\" I add to the\nperception a concept of the understanding, viz., that of cause, which\nconnects with the concept of sunshine that of heat as a necessary\nconsequence, and the synthetical judgment becomes of necessity\nuniversally valid, viz., objective, and is converted from a perception\ninto experience.\n===================================\n\nIf all our synthetical judgments are analysed so far as they are\nobjectively valid, it will be found that they never consist of mere\nintuitions connected only (as is commonly believed) by comparison into\na judgment; but that they would be impossible were not a pure concept\nof the understanding superadded to the concepts abstracted from\nintuition, under which concept these latter are subsumed, and in this\nmanner only combined into an objectively valid judgment. Even the\njudgments of pure mathematics in their simplest axioms are not exempt\nfrom this condition. The principle, \"a straight line is the shortest\nbetween two points,\" presupposes that the line is subsumed under the\nconcept of quantity, which certainly is no mere intuition, but has its\nseat in the understanding alone, and serves to determine the intuition\n(of the line) with regard to the judgments which may be made about it,\nrelatively to their quantity, that is, to plurality (as judicia\nplurativa).{14} For under them it is understood that in a given\nintuition there is contained a plurality of homogenous parts.\n\n===================================\n{14} This name seems preferable to the term particularia, which is used\nfor these judgments in logic. For the latter implies the idea that\nthey are not universal. But when I start from unity (in single\njudgments) and so proceed to universality, I must not [even indirectly\nand negatively] imply any reference to universality. I think plurality\nmerely without universality, and not the exception from universality.\nThis is necessary, if logical considerations shall form the basis of\nthe pure concepts of the understanding. However, there is no need of\nmaking changes in logic.\n===================================\n\n\u00a7 21. To prove, then, the possibility of experience so far as it\nrests upon pure concepts of the understanding a priori, we must first\nrepresent what belongs to judgments in general and the various\nfunctions of the understanding, in a complete table. For the pure\nconcepts of the understanding must run parallel to these functions, as\nsuch concepts are nothing more than concepts of intuitions in general,\nso far as these are determined by one or other of these functions of\njudging, in themselves, that is, necessarily and universally. Hereby\nalso the a priori principles of the possibility of all experience, as\nof an objectively valid empirical cognition, will be precisely\ndetermined. For they are nothing but propositions by which all\nperception is (under certain universal conditions of intuition)\nsubsumed under those pure concepts of the understanding.\n\n\nLogical Table of Judgments.\n\n     1.                             2.\nAs to Quantity.               As to Quality.\n  Universal.                    Affirmative.\n  Particular.                   Negative.\n  Singular.                     Infinite.\n\n     3.                             4.\nAs to Relation.               As to Modality.\n  Categorical.                  Problematical.\n  Hypothetical.                 Assertorial.\n  Disjunctive.                  Apodeictical.\n\n\nTranscendental Table of the Pure Concepts of the Understanding.\n\n     1.                             2.\nAs to Quantity.               As to Quality.\n  Unity (the Measure).          Reality.\n  Plurality (the Quantity).     Negation.\n  Totality (the Whole).         Limitation.\n\n     3.                             4.\nAs to Relation.               As to Modality.\n  Substance.                    Possibility.\n  Cause.                        Existence.\n  Community.                    Necessity.\n\n\nPure Physiological Table of the Universal Principles of the Science of Nature.\n\n        1.                                2.\nAxioms of Intuition.        Anticipations of Perception.\n\n        3.                                4.\nAnalogies of Experience.    Postulates of Empirical Thinking\n                                       generally.\n\n\n\u00a7 21a. In order to comprise the whole matter in one idea, it is first\nnecessary to remind the reader that we are discussing not the origin\nof experience, but of that which lies in experience. The former\npertains to empirical psychology, and would even then never be\nadequately explained without the latter, which belongs to the Critique\nof cognition, and particularly of the understanding.\n\nExperience consists of intuitions, which belong to the sensibility,\nand of judgments, which are entirely a work of the understanding. But\nthe judgments, which the understanding forms alone from sensuous\nintuitions, are far from being judgments of experience. For in the one\ncase the judgment connects only the perceptions as they are given in\nthe sensuous intuition, while in the other the judgments must express\nwhat experience in general, and not what the mere perception (which\npossesses only subjective validity) contains. The judgment of\nexperience must therefore add to the sensuous intuition and its\nlogical connexion in a judgment (after it has been rendered universal\nby comparison) something that determines the synthetical judgment as\nnecessary and therefore as universally valid. This can be nothing else\nthan that concept which represents the intuition as determined in\nitself with regard to one form of judgment rather than another, viz.,\na concept of that synthetical unity of intuitions which can only be\nrepresented by a given logical function of judgments.\n\n\u00a7 22. The sum of the matter is this: the business of the senses is to\nintuite\u2014that of the understanding is to think. But thinking is\nuniting representations in one consciousness. This union originates\neither merely relative to the subject, and is accidental and\nsubjective, or is absolute, and is necessary or objective. The union\nof representations in one consciousness is judgment. Thinking\ntherefore is the same as judging, or referring representations to\njudgments in general. Hence judgments are either merely subjective,\nwhen representations are referred to a consciousness in one subject\nonly, and united in it, or objective, when they are united in a\nconsciousness generally, that is, necessarily. The logical functions\nof all judgments are but various modes of uniting representations in\nconsciousness. But if they serve for concepts, they are concepts of\ntheir necessary union in a consciousness, and so principles of\nobjectively valid judgments. This union in a consciousness is either\nanalytical, by identity, or synthetical, by the combination and\naddition of various representations one to another. Experience\nconsists in the synthetical connexion of phenomena (perceptions) in\nconsciousness, so far as this connexion is necessary. Hence the pure\nconcepts of the understanding are those under which all perceptions\nmust be subsumed ere they can serve for judgments of experience, in\nwhich the synthetical unity of the perceptions is represented as\nnecessary and universally valid.{15}\n\n===================================\n{15} But how does this proposition, \"that judgments of experience\ncontain necessity in the synthesis of perceptions,\" agree with my\nstatement so often before inculcated, that \"experience as cognition a\nposteriori can afford contingent judgments only?\" When I say that\nexperience teaches me something, I mean only the perception that lies\nin experience,\u2014for example, that heat always follows the shining of\nthe sun on a stone; consequently the proposition of experience is\nalways so far accidental. That this heat necessarily follows the\nshining of the sun is contained indeed in the judgment of experience\n(by means of the concept of cause), yet is a fact not learned by\nexperience; for conversely, experience is first of all generated by\nthis addition of the concept of the understanding (of cause) to\nperception. How perception attains this addition may be seen by\nreferring in the Critique itself to the section on the Transcendental\nfaculty of Judgment [viz., in the first edition, Von dem Schematismus\nder reinen Verstandsbegriffe].\n===================================\n\n\u00a7\u00a023. Judgments, when considered merely as the condition of the\nunion of given representations in a consciousness, are rules. These\nrules, so far as they represent the union as necessary, are rules a\npriori, and so far as they cannot be deduced from higher rules, are\nfundamental principles. But in regard to the possibility of all\nexperience, merely in relation to the form of thinking in it, no\nconditions of judgments of experience are higher than those which\nbring the phenomena, according to the various form of their intuition,\nunder pure concepts of the understanding, and render the empirical\njudgment objectively valid. These concepts are therefore the a priori\nprinciples of possible experience.\n\nThe principles of possible experience are then at the same time\nuniversal laws of nature, which can be cognised a priori. And thus the\nproblem in our second question, \"How is the pure Science of Nature\npossible?\" is solved. For the system which is required for the form of\na science is to be met with in perfection here, because, beyond the\nabove-mentioned formal conditions of all judgments in general offered\nin logic, no others are possible, and these constitute a logical\nsystem. The concepts grounded thereupon, which contain the a priori\nconditions of all synthetical and necessary judgments, accordingly\nconstitute a transcendental system. Finally the principles, by means\nof which all phenomena are subsumed under these concepts, constitute a\nphysical{16} system, that is, a system of nature, which precedes all\nempirical cognition of nature, makes it even possible, and hence may\nin strictness be denominated the universal and pure science of nature.\n\n===================================\n{16} [Kant uses the term physiological in its etymological meaning as\n\"pertaining to the science of physics,\" i.e., nature in general, not\nas we use the term now as \"pertaining to the functions of the living\nbody.\" Accordingly it has been translated \"physical.\"\u2014Ed.]\n===================================\n\n\u00a7 24. The first one{17} of the physiological principles subsumes all\nphenomena, as intuitions in space and time, under the concept of\nQuantity, and is so far a principle of the application of Mathematics\nto experience. The second one subsumes the empirical element, viz.,\nsensation which denotes the real in intuitions, not indeed directly\nunder the concept of quantity, because sensation is not an intuition\nthat contains either space or time, though it places the respective\nobject into both. But still there is between reality\n(sense-representation) and the zero, or total void of intuition in\ntime, a difference which has a quantity. For between every given\ndegree of light and of darkness, between every degree of heat and of\nabsolute cold, between every degree of weight and of absolute\nlightness, between every degree of occupied space and of totally void\nspace, diminishing degrees can be conceived, in the same manner as\nbetween consciousness and total unconsciousness (the darkness of a\npsychological blank) ever diminishing degrees obtain. Hence there is\nno perception that can prove an absolute absence of it; for instance,\nno psychological darkness that cannot be considered as a kind of\nconsciousness. This occurs in all cases of sensation, and so the\nunderstanding can anticipate even sensations, which constitute the\npeculiar quality of empirical representations (appearances), by means\nof the principle: \"that they all have (consequently that what is real\nin all phenomena has) a degree.\" Here is the second application of\nmathematics (mathesis intensorum) to the science of nature.\n\n===================================\n{17} The three following paragraphs will hardly be understood unless\nreference be made to what the Critique itself says on the subject of\nthe Principles; they will, however, be of service in giving a general\nview of the Principles, and in fixing the attention on the main\npoints.\n===================================\n\n\u00a7 25. Anent the relation of appearances merely with a view to their\nexistence, the determination is not mathematical but dynamical, and\ncan never be objectively valid, consequently never fit for experience,\nif it does not come under a priori principles by which the cognition\nof experience relative to appearances becomes even possible. Hence\nappearances must be subsumed under the concept of Substance, which is\nthe foundation of all determination of existence, as a concept of the\nthing itself; or secondly\u2014so far as, a succession is found among\nphenomena, that is, an event\u2014under the concept of an Effect with\nreference to Cause; or lastly\u2014so far as coexistence is to be known\nobjectively, that is, by a judgment of experience\u2014under the concept\nof Community (action and reaction).{18} Thus a priori principles form\nthe basis of objectively valid, though empirical judgments, that is,\nof the possibility of experience so far as it must connect objects as\nexisting in nature. These principles are the proper laws of nature,\nwhich may be termed dynamical.\n\n===================================\n{18} [Kant uses here the equivocal term Wechselwirkung.\u2014Ed.]\n===================================\n\nFinally the cognition of the agreement and connexion not only of\nappearances among themselves in experience, but of their relation to\nexperience in general, belongs to the judgments of experience. This\nrelation contains either their agreement with the formal conditions,\nwhich the understanding cognises, or their coherence with the\nmaterials of the senses and of perception, or combines both into one\nconcept. Consequently it contains Possibility, Actuality, and\nNecessity according to universal laws of nature; and this constitutes\nthe physical doctrine of method, or the distinction of truth and of\nhypotheses, and the bounds of the certainty of the latter.\n\n\u00a7 26. The third table of Principles drawn from the nature of the\nunderstanding itself after the critical method, shows an inherent\nperfection, which raises it far above every other table which has\nhitherto though in vain been tried or may yet be tried by analysing\nthe objects themselves dogmatically. It exhibits all synthetical a\npriori principles completely and according to one principle, viz., the\nfaculty of judging in general, constituting the essence of experience\nas regards the understanding, so that we can be certain that there are\nno more such principles, a satisfaction such as can never be attained\nby the dogmatical method. Yet is this not all: there is a still\ngreater merit in it.\n\nWe must carefully bear in mind the proof which shows the possibility\nof this cognition a priori, and at the same time limits all such\nprinciples to a condition which must never be lost sight of, if we\ndesire it not to be misunderstood, and extended in use beyond the\noriginal sense which the understanding attaches to it. This limit is\nthat they contain nothing but the conditions of possible experience in\ngeneral so far as it is subjected to laws a priori. Consequently I do\nnot say, that things in themselves possess a quantity, that their\nactuality possesses a degree, their existence a connexion of accidents\nin a substance, etc. This nobody can prove, because such a synthetical\nconnexion from mere concepts, without any reference to sensuous\nintuition on the one side, or connexion of it in a possible experience\non the other, is absolutely impossible. The essential limitation of\nthe concepts in these principles then is: That all things stand\nnecessarily a priori under the afore-mentioned conditions, as objects\nof experience only.\n\nHence there follows secondly a specifically peculiar mode of proof of\nthese principles: they are not directly referred to appearances and to\ntheir relations, but to the possibility of experience, of which\nappearances constitute the matter only, not the form. Thus they are\nreferred to objectively and universally valid synthetical\npropositions, in which we distinguish judgments of experience from\nthose of perception. This takes place because appearances, as mere\nintuitions, occupying a part of space and time, come under the concept\nof Quantity, which unites their multiplicity a priori according to\nrules synthetically. Again, so far as the perception contains, besides\nintuition, sensibility, and between the latter and nothing (i.e., the\ntotal disappearance of sensibility), there is an ever decreasing\ntransition, it is apparent that that which is in appearances must have\na degree, so far as it (viz., the perception) does not itself occupy\nany part of space or of time.{19} Still the transition to actuality from\nempty time or empty space is only possible in time; consequently\nthough sensibility, as the quality of empirical intuition, can never\nbe cognised a priori, by its specific difference from other\nsensibilities, yet it can, in a possible experience in general, as a\nquantity of perception be intensely distinguished from every other\nsimilar perception. Hence the application of mathematics to nature, as\nregards the sensuous intuition by which nature is given to us, becomes\npossible and is thus determined.\n\n===================================\n{19} Heat and light are in a small space just as large as to degree as\nin a large one; in like manner the internal representations, pain,\nconsciousness in general, whether they last a short or a long time,\nneed not vary as to the degree. Hence the quantity is here in a point\nand in a moment just as great as in any space or time however great.\nDegrees are therefore capable of increase, but not in intuition,\nrather in mere sensation (or the quantity of the degree of an\nintuition). Hence they can only be estimated quantitatively by the\nrelation of 1 to 0, viz., by their capability of decreasing by\ninfinite intermediate degrees to disappearance, or of increasing from\nnaught through infinite gradations to a determinate sensation in a\ncertain time. Quantitas qualitatis est gradus [i.e., the degrees of\nquality must be measured by equality].\n===================================\n\nAbove all, the reader must pay attention to the mode of proof of the\nprinciples which occur under the title of Analogies of experience. For\nthese do not refer to the genesis of intuitions, as do the principles\nof applied mathematics, but to the connexion of their existence in\nexperience; and this can be nothing but the determination of their\nexistence in time according to necessary laws, under which alone the\nconnexion is objectively valid, and thus becomes experience. The proof\ntherefore does not turn on the synthetical unity in the connexion of\nthings in themselves, but merely of perceptions, and of these not in\nregard to their matter, but to the determination of time and of the\nrelation of their existence in it, according to universal laws. If the\nempirical determination in relative time is indeed objectively valid\n(i.e., experience), these universal laws contain the necessary\ndetermination of existence in time generally (viz., according to a\nrule of the understanding a priori).\n\nIn these Prolegomena I cannot further descant on the subject, but my\nreader (who has probably been long accustomed to consider experience a\nmere empirical synthesis of perceptions, and hence not considered that\nit goes much beyond them, as it imparts to empirical judgments\nuniversal validity, and for that purpose requires a pure and a priori\nunity of the understanding) is recommended to pay special attention to\nthis distinction of experience from a mere aggregate of perceptions,\nand to judge the mode of proof from this point of view.\n\n\u00a7 27. Now we are prepared to remove Hume's doubt. He justly\nmaintains, that we cannot comprehend by reason the possibility of\nCausality, that is, of the reference of the existence of one thing to\nthe existence of another, which is necessitated by the former. I add,\nthat we comprehend just as little the concept of Subsistence, that is,\nthe necessity that at the foundation of the existence of things there\nlies a subject which cannot itself be a predicate of any other thing;\nnay, we cannot even form a notion of the possibility of such a thing\n(though we can point out examples of its use in experience). The very\nsame in comprehensibility affects the Community of things, as we\ncannot comprehend how from the state of one thing an inference to the\nstate of quite another thing beyond it, and vice versa, can be drawn,\nand how substances which have each their own separate existence should\ndepend upon one another necessarily. But I am very far from holding\nthese concepts to be derived merely from experience, and the necessity\nrepresented in them, to be imaginary and a mere illusion produced in\nus by long habit. On the contrary, I have amply shown, that they and\nthe theorems derived from them are firmly established a priori, or\nbefore all experience, and have their undoubted objective value,\nthough only with regard to experience.\n\n\u00a7 28. Though I have no notion of such a connexion of things in\nthemselves, that they can either exist as substances, or act as\ncauses, or stand in community with others (as parts of a real whole),\nand I can just as little conceive such properties in appearances as\nsuch (because those concepts contain nothing that lies in the\nappearances, but only what the understanding alone must think): we\nhave yet a notion of such a connexion of representations in our\nunderstanding, and in judgments generally; consisting in this that\nrepresentations appear in one sort of judgments as subject in relation\nto predicates, in another as reason in relation to consequences, and\nin a third as parts, which constitute together a total possible\ncognition. Besides we cognise a priori that without considering the\nrepresentation of an object as determined in some of these respects,\nwe can have no valid cognition of the object, and, if we should occupy\nourselves about the object in itself, there is no possible attribute,\nby which I could know that it is determined under any of these\naspects, that is, under the concept either of substance, or of cause,\nor (in relation to other substances) of community, for I have no\nnotion of the possibility of such a connexion of existence. But the\nquestion is not how things in themselves, but how the empirical\ncognition of things is determined, as regards the above aspects of\njudgments in general, that is, how things, as objects of experience,\ncan and shall be subsumed under these concepts of the understanding.\nAnd then it is clear, that I completely comprehend not only the\npossibility, but also the necessity of subsuming all phenomena under\nthese concepts, that is, of using them for principles of the\npossibility of experience.\n\n\u00a7 29. When making an experiment with Hume's problematical concept\n(his crux metaphysicorum), the concept of cause, we have, in the first\nplace, given a priori, by means of logic, the form of a conditional\njudgment in general, i.e., we have one given cognition as antecedent\nand another as consequence. But it is possible, that in perception we\nmay meet with a rule of relation, which runs thus: that a certain\nphenomenon is constantly followed by another (though not conversely),\nand this is a case for me to use the hypothetical judgment, and, for\ninstance, to say, it the sun shines long enough upon a body, it grows\nwarm. Here there is indeed as yet no necessity of connexion, or\nconcept of cause. But I proceed and say, that if this proposition,\nwhich is merely a subjective connexion of perceptions, is to be a\njudgment of experience, it must be considered as necessary and\nuniversally valid. Such a proposition would be, \"the sun is by its\nlight the cause of heat.\" The empirical rule is now considered as a\nlaw, and as valid not merely of appearances but valid of them for the\npurposes of a possible experience which requires universal and\ntherefore necessarily valid rules. I therefore easily comprehend the\nconcept of cause, as a concept necessarily belonging to the mere form\nof experience, and its possibility as a synthetical union of\nperceptions in consciousness generally; but I do not at all comprehend\nthe possibility of a thing generally as a cause, because the concept\nof cause denotes a condition not at all belonging to things, but to\nexperience. It is nothing in fact but an objectively valid cognition\nof appearances and of their succession, so far as the antecedent can\nbe conjoined with the consequent according to the rule of hypothetical\njudgments.\n\n\u00a7 30. Hence if the pure concepts of the understanding do not refer to\nobjects of experience but to things in themselves (noumena), they have\nno signification whatever. They serve, as it were, only to decipher\nappearances, that we may be able to read them as experience. The\nprinciples which arise from their reference to the sensible world,\nonly serve our understanding for empirical use. Beyond this they are\narbitrary combinations, without objective reality, and we can neither\ncognise their possibility a priori, nor verify their reference to\nobjects, let alone make it intelligible by any example; because\nexamples can only be borrowed from some possible experience,\nconsequently the objects of these concepts can be found nowhere but in\na possible experience.\n\nThis complete (though to its originator unexpected) solution of Hume's\nproblem rescues for the pure concepts of the understanding their a\npriori origin, and for the universal laws of nature their validity, as\nlaws of the understanding, yet in such a way as to limit their use to\nexperience, because their possibility depends solely on the reference\nof the understanding to experience, but with a completely reversed\nmode of connexion which never occurred to Hume, not by deriving them\nfrom experience, but by deriving experience from them.\n\nThis is therefore the result of all our foregoing inquiries: \"All\nsynthetical principles a priori are nothing more than principles of\npossible experience, and can never be referred to things in\nthemselves, but to appearances as objects of experience. And hence\npure mathematics as well as a pure science of nature can never be\nreferred to anything more than mere appearances, and can only\nrepresent either that which makes experience generally possible, or\nelse that which, as it is derived from these principles, must always\nbe capable of being represented in some possible experience.\n\n\u00a7 31. And thus we have at last something definite, upon which to\ndepend in all metaphysical enterprises, which have hitherto, boldly\nenough but always at random, attempted everything without\ndiscrimination. That the aim of their exertions should be so near,\nstruck neither the dogmatical thinkers nor those who, confident in\ntheir supposed sound common sense, started with concepts and\nprinciples of pure reason (which were legitimate and natural, but\ndestined for mere empirical use) in quest of fields of knowledge, to\nwhich they neither knew nor could know any determinate bounds, because\nthey had never reflected nor were able to reflect on the nature or\neven on the possibility of such a pure understanding.\n\nMany a naturalist of pure reason (by which I mean the man who believes\nhe can decide in matters of metaphysics without any science) may\npretend, that he long ago by the prophetic spirit of his sound sense,\nnot only suspected, but knew and comprehended, what is here propounded\nwith so much ado, or, if he likes, with prolix and pedantic pomp:\n\"that with all our reason we can never reach beyond the field of\nexperience.\" But when he is questioned about his rational principles\nindividually, he must grant, that there are many of them which he has\nnot taken from experience, and which are therefore independent of it\nand valid a priori. How then and on what grounds will he restrain both\nhimself and the dogmatist, who makes use of these concepts and\nprinciples beyond all possible experience, because they are recognised\nto be independent of it? And even he, this adept in sound sense, in\nspite of all his assumed and cheaply acquired wisdom, is not exempt\nfrom wandering inadvertently beyond objects of experience into the\nfield of chimeras. He is often deeply enough involved in them, though\nin announcing everything as mere probability, rational conjecture, or\nanalogy, he gives by his popular language a color to his groundless\npretensions.\n\n\u00a7 32. Since the oldest days of philosophy inquirers into pure reason\nhave conceived, besides the things of sense, or appearances\n(phenomena), which make up the sensible world, certain creations of\nthe understanding (Verstandeswesen), called noumena, which should\nconstitute an intelligible world. And as appearance and illusion were\nby those men identified (a thing which we may well excuse in an\nundeveloped epoch), actuality was only conceded to the creations of\nthought.\n\nAnd we indeed, rightly considering objects of sense as mere\nappearances, confess thereby that they are based upon a thing in\nitself, though we know not this thing in its internal constitution,\nbut only know its appearances, viz., the way in which our senses are\naffected by this unknown something. The understanding therefore, by\nassuming appearances, grants the existence of things in themselves\nalso, and so far we may say, that the representation of such things as\nform the basis of phenomena, consequently of mere creations of the\nunderstanding, is not only admissible, but unavoidable.\n\nOur critical deduction by no means excludes things of that sort\n(noumena), but rather limits the principles of the Aesthetic (the\nscience of the sensibility) to this, that they shall not extend to all\nthings, as everything would then be turned into mere appearance, but\nthat they shall only hold good of objects of possible experience.\nHereby then objects of the understanding are granted, but with the\ninculcation of this rule which admits of no exception: \"that we\nneither know nor can know anything at all definite of these pure\nobjects of the understanding, because our pure concepts of the\nunderstanding as well as our pure intuitions extend to nothing but\nobjects of possible experience, consequently to mere things of sense,\nand as soon as we leave this sphere these concepts retain no meaning\nwhatever.\"\n\n\u00a7 33. There is indeed something seductive in our pure concepts of the\nunderstanding, which tempts us to a transcendent use, \u2014a use which\ntranscends all possible experience. Not only are our concepts of\nsubstance, of power, of action, of reality, and others, quite\nindependent of experience, containing nothing of sense appearance, and\nso apparently applicable to things in themselves (noumena), but, what\nstrengthens this conjecture, they contain a necessity of determination\nin themselves, which experience never attains. The concept of cause\nimplies a rule, according to which one state follows another\nnecessarily; but experience can only show us, that one state of things\noften, or at most, commonly, follows another, and therefore affords\nneither strict universality, nor necessity.\n\nHence the Categories seem to have a deeper meaning and import than can\nbe exhausted by their empirical use, and so the understanding\ninadvertently adds for itself to the house of experience a much more\nextensive wing, which it fills with nothing but creatures of thought,\nwithout ever observing that it has transgressed with its otherwise\nlawful concepts the bounds of their use.\n\n\u00a7 34. Two important, and even indispensable, though very dry,\ninvestigations had therefore become indispensable in the Critique of\nPure Reason,\u2014viz., the two chapters \"Vom Schematismus der reinen\nVerstandsbegriffe,\" and \"Vom Grunde der Unterscheidung aller\nVerstandesbegriffe \u00fcberhaupt in Ph\u00e4nomena und Noumena.\" In the\nformer it is shown, that the senses furnish not the pure concepts of\nthe understanding in concreto, but only the schedule for their use,\nand that the object conformable to it occurs only in experience (as\nthe product of the understanding from materials of the sensibility).\nIn the latter it is shown, that, although our pure concepts of the\nunderstanding and our principles are independent of experience, and\ndespite of the apparently greater sphere of their use, still nothing\nwhatever can be thought by them beyond the field of experience,\nbecause they can do nothing but merely determine the logical form of\nthe judgment relatively to given intuitions. But as there is no\nintuition at all beyond the field of the sensibility, these pure\nconcepts, as they cannot possibly be exhibited in concreto, are void\nof all meaning; consequently all these noumena, together with their\ncomplex, the intelligible world,{20} are nothing but representation of a\nproblem, of which the object in itself is possible, but the solution,\nfrom the nature of our understanding, totally impossible. For our\nunderstanding is not a faculty of intuition, but of the connexion of\ngiven intuitions in experience. Experience must therefore contain all\nthe objects for our concepts; but beyond it no concepts have any\nsignificance, as there is no intuition that might offer them a\nfoundation.\n\n===================================\n{20} We speak of the \"intelligible world,\" not (as the usual expression\nis) \"intellectual world.\" For cognitions are intellectual through the\nunderstanding, and refer to our world of sense also; but objects, so\nfar as they can be represented merely by the understanding, and to\nwhich none of our sensible intuitions can refer, are termed\n\"intelligible.\" But as some possible intuition must correspond to\nevery object, we would have to assume an understanding that intuites\nthings immediately; but of such we have not the least notion, nor have\nwe of the things of the understanding [Verstandeswesen], to which it\nshould be applied.\n===================================\n\n\u00a7 35. The imagination may perhaps be forgiven for occasional\nvagaries, and for not keeping carefully within the limits of\nexperience, since it gains life and vigor by such flights, and since\nit is always easier to moderate its boldness, than to stimulate its\nlanguor. But the understanding which ought to think can never be\nforgiven for indulging in vagaries; for we depend upon it alone for\nassistance to set bounds, when necessary, to the vagaries of the\nimagination.\n\nBut the understanding begins its aberrations very innocently and\nmodestly. It first elucidates the elementary cognitions, which inhere\nin it prior to all experience, but yet must always have their\napplication in experience. It gradually drops these limits, and what\nis there to prevent it, as it has quite freely derived its principles\nfrom itself? And then it proceeds first to newly-imagined powers in\nnature, then to beings, outside nature; in short to a world, for whose\nconstruction the materials cannot be wanting, because fertile fiction\nfurnishes them abundantly, and though not confirmed, is never refuted,\nby experience. This is the reason that young thinkers are so partial\nto metaphysics of the truly dogmatical kind, and often sacrifice to it\ntheir time and their talents, which might be otherwise better\nemployed.\n\nBut there is no use in trying to moderate these fruitless endeavors of\npure reason by all manner of cautions as to the difficulties of\nsolving questions so occult, by complaints of the limits of our\nreason, and by degrading our assertions into mere conjectures. For if\ntheir impossibility is not distinctly shown, and reason's cognition of\nits own essence does not become a true science, in which the field of\nits right use is distinguished, so to say, with mathematical certainty\nfrom that of its worthless and idle use, these fruitless efforts will\nnever be abandoned for good.\n\n\u00a7 36. How is Nature itself possible?\n\nThis question\u2014the highest point that transcendental philosophy can\never reach, and to which, as its boundary and completion, it must\nproceed\u2014properly contains two questions.\n\nFirst: How is nature at all possible in the material sense, by\nintuition, considered as the totality of appearances; how are space,\ntime, and that which fills both\u2014the object of sensation, in general\npossible? The answer is: By means of the constitution of our\nSensibility, according to which it is specifically affected by\nobjects, which are in themselves unknown to it, and totally distinct\nfrom those phenomena. This answer is given in the Critique itself in\nthe transcendental Aesthetic, and in these Prolegomena by the solution\nof the first general problem.\n\nSecondly: How is nature possible in the formal sense, as the totality\nof the rules, under which all phenomena must come, in order to be\nthought as connected in experience? The answer must be this: It is\nonly possible by means of the constitution of our Understanding,\naccording to which all the above representations of the sensibility\nare necessarily referred to a consciousness, and by which the peculiar\nway in which we think (viz., by rules), and hence experience also, are\npossible, but must be clearly distinguished from an insight into the\nobjects in themselves. This answer is given in the Critique itself in\nthe transcendental Logic, and in these Prolegomena, in the course of\nthe solution of the second main problem.\n\nBut how this peculiar property of our sensibility itself is possible,\nor that of our understanding and of the apperception which is\nnecessarily its basis and that of all thinking, cannot be further\nanalysed or answered, because it is of them that we are in need for\nall our answers and for all our thinking about objects.\n\nThere are many laws of nature, which we can only know by means of\nexperience; but conformity to law in the connexion of appearances,\ni.e., in nature in general, we cannot discover by any experience,\nbecause experience itself requires laws which are a priori at the\nbasis of its possibility.\n\nThe possibility of experience in general is therefore at the same time\nthe universal law of nature, and the principles of the experience are\nthe very laws of nature. For we do not know nature but as the totality\nof appearances, i.e., of representations in us, and hence we can only\nderive the laws of its connexion from the principles of their\nconnexion in us, that is, from the conditions of their necessary union\nin consciousness, which constitutes the possibility of experience.\n\nEven the main proposition expounded throughout this section\u2014that\nuniversal laws of nature can be distinctly cognised a priori\u2014leads\nnaturally to the proposition: that the highest legislation of nature\nmust lie in ourselves, i.e., in our understanding, and that we must\nnot seek the universal laws of nature in nature by means of\nexperience, but conversely must seek nature, as to its universal\nconformity to law, in the conditions of the possibility of experience,\nwhich lie in our sensibility and in our understanding. For how were it\notherwise possible to know a priori these laws, as they are not rules\nof analytical cognition, but truly synthetical extensions of it?\n\nSuch a necessary agreement of the principles of possible experience\nwith the laws of the possibility of nature, can only proceed from one\nof two reasons: either these laws are drawn from nature by means of\nexperience, or conversely nature is derived from the laws of the\npossibility of experience in general, and is quite the same as the\nmere universal conformity to law of the latter. The former is\nself-contradictory, for the universal laws of nature can and must be\ncognised a priori (that is, independent of all experience), and be the\nfoundation of all empirical use of the understanding; the latter\nalternative therefore alone remains.{21}\n\n===================================\n{21} Crusius alone thought of a compromise: that a Spirit, who can\nneither err nor deceive, implanted these laws in us originally. But\nsince false principles often intrude themselves, as indeed the very\nsystem of this man shows in not a few examples, we are involved in\ndifficulties as to the use of such a principle in the absence of sure\ncriteria to distinguish the genuine origin from the spurious, as we\nnever can know certainly what the Spirit of truth or the father of\nlies may have instilled into us.\n===================================\n\nBut we must distinguish the empirical laws of nature, which always\npresuppose particular perceptions, from the pure or universal laws of\nnature, which, without being based on particular perceptions, contain\nmerely the conditions of their necessary union in experience. In\nrelation to the latter, nature and possible experience are quite the\nsame, and as the conformity to law here depends upon the necessary\nconnexion of appearances in experience (without which we cannot\ncognise any object whatever in the sensible world), consequently upon\nthe original laws of the understanding, it seems at first strange, but\nis not the less certain, to say:\n\nThe understanding does not derive its laws (a priori) from, but\nprescribes them to, nature.\n\n\u00a7 37. We shall illustrate this seemingly bold proposition by an\nexample, which will show, that laws, which we discover in objects of\nsensuous intuition (especially when these laws are cognised as\nnecessary), are commonly held by us to be such as have been placed\nthere by the understanding, in spite of their being similar in all\npoints to the laws of nature, which we ascribe to experience.\n\n\u00a7 38. If we consider the properties of the circle, by which this\nfigure combines so many arbitrary determinations of space in itself,\nat once in a universal rule, we cannot avoid attributing a\nconstitution (eine Natur) to this geometrical thing. Two right lines,\nfor example, which intersect one another and the circle, howsoever\nthey may be drawn, are always divided so that the rectangle\nconstructed with the segments of the one is equal to that constructed\nwith the segments of the other. The question now is: Does this law lie\nin the circle or in the understanding, that is, Does this figure,\nindependently of the understanding, contain in itself the ground of\nthe law, or does the understanding, having constructed according to\nits concepts (according to the quality of the radii) the figure\nitself, introduce into it this law of the chords cutting one another\nin geometrical proportion? When we follow the proofs of this law, we\nsoon perceive, that it can only be derived from the condition on which\nthe understanding founds the construction of this figure, and which is\nthat of the equality of the radii. But, if we enlarge this concept, to\npursue further the unity of various properties of geometrical figures\nunder common laws, and consider the circle as a conic section, which\nof course is subject to the same fundamental conditions of\nconstruction as other conic sections, we shall find that all the\nchords which intersect within the ellipse, parabola, and hyperbola,\nalways intersect so that the rectangles of their segments are not\nindeed equal, but always bear a constant ratio to one another. If we\nproceed still farther, to the fundamental laws of physical astronomy,\nwe find a physical law of reciprocal attraction diffused over all\nmaterial nature, the rule of which is: \"that it decreases inversely as\nthe square of the distance from each attracting point, i.e., as the\nspherical surfaces increase, over which this force spreads,\" which law\nseems to be necessarily inherent in the very nature of things, and\nhence is usually propounded as cognisable a priori. Simple as the\nsources of this law are, merely resting upon the relation of spherical\nsurfaces of different radii, its consequences are so valuable with\nregard to the variety of their agreement and its regularity, that not\nonly are all possible orbits of the celestial bodies conic sections,\nbut such a relation of these orbits to each other results, that no\nother law of attraction, than that of the inverse square of the\ndistance, can be imagined as fit for a cosmical system.\n\nHere accordingly is a nature that rests upon laws which the\nunderstanding cognises a priori, and chiefly from the universal\nprinciples of the determination of space. Now I ask:\n\nDo the laws of nature lie in space, and does the understanding learn\nthem by merely endeavoring to find out the enormous wealth of meaning\nthat lies in space; or do they inhere in the understanding and in the\nway in which it determines space according to the conditions of the\nsynthetical unity in which its concepts are all centred?\n\nSpace is something so uniform and as to all particular properties so\nindeterminate, that we should certainly not seek a store of laws of\nnature in it. Whereas that which determines space to assume the form\nof a circle or the figures of a cone and a sphere, is the\nunderstanding, so far as it contains the ground of the unity of their\nconstructions.\n\nThe mere universal form of intuition, called space, must therefore be\nthe substratum of all intuitions determinable to particular objects,\nand in it of course the condition of the possibility and of the\nvariety of these intuitions lies. But the unity of the objects is\nentirely determined by the understanding, and on conditions which lie\nin its own nature; and thus the understanding is the origin of the\nuniversal order of nature, in that it comprehends all appearances\nunder its own laws, and thereby first constructs, a priori, experience\n(as to its form), by means of which whatever is to be cognised only by\nexperience, is necessarily subjected to its laws. For we are not now\nconcerned with the nature of things in themselves, which is\nindependent of the conditions both of our sensibility and our\nunderstanding, but with nature, as an object of possible experience,\nand in this case the understanding, whilst it makes experience\npossible, thereby insists that the sensuous world is either not an\nobject of experience at all, or must be nature [viz., an existence of\nthings, determined according to universal laws{22}].\n\n===================================\n{22} The definition of nature is given in the beginning of the Second\nPart of the \"Transcendental Problem,\" in \u00a7 14.\n===================================\n\nAPPENDIX TO THE PURE SCIENCE OF NATURE.\n\n\u00a7 39. Of the System of the Categories.\n\nThere can be nothing more desirable to a philosopher, than to be able\nto derive the scattered multiplicity of the concepts or the\nprinciples, which had occurred to him in concrete use, from a\nprinciple a priori, and to unite everything in this way in one\ncognition. He formerly only believed that those things, which remained\nafter a certain abstraction, and seemed by comparison among one\nanother to constitute a particular kind of cognitions, were completely\ncollected; but this was only an Aggregate. Now he knows, that just so\nmany, neither more nor less, can constitute the mode of cognition, and\nperceives the necessity of his division, which constitutes\ncomprehension; and now only he has attained a System.\n\nTo search in our daily cognition for the concepts, which do not rest\nupon particular experience, and yet occur in all cognition of\nexperience, where they as it were constitute the mere form of\nconnexion, presupposes neither greater reflexion nor deeper insight,\nthan to detect in a language the rules of the actual use of words\ngenerally, and thus to collect elements for a grammar. In fact both\nresearches are very nearly related, even though we are not able to\ngive a reason why each language has just this and no other formal\nconstitution, and still less why an exact number of such formal\ndeterminations in general are found in it.\n\nAristotle collected ten pure elementary concepts under the name of\nCategories.{23} To these, which are also called predicaments, he found\nhimself obliged afterwards to add five post-predicaments,{24} some of\nwhich however (prius, simul, and motus) are contained in the former;\nbut this random collection must be considered (and commended) as a\nmere hint for future inquirers, not as a regularly developed idea, and\nhence it has, in the present more advanced state of philosophy, been\nrejected as quite useless.\n\n===================================\n{23} 1. Substantia. 2. Qualitas. 3. Quantitas. 4. Relatio, 5. Actio.\n6. Passio. 7. Quando, 8. Ubi. 9. Situs. 10. Habitus.\n\n{24} Oppositum. Prius. Simul. Motus. Habere.\n===================================\n\nAfter long reflexion on the pure elements of human knowledge (those\nwhich contain nothing empirical), I at last succeeded in\ndistinguishing with certainty and in separating the pure elementary\nnotions of the Sensibility (space and time) from those of the\nUnderstanding. Thus the 7th, 8th, and 9th Categories had to be\nexcluded from the old list. And the others were of no service to me;\nbecause there was no principle [in them], on which the understanding\ncould be investigated, measured in its completion, and all the\nfunctions, whence its pure concepts arise, determined exhaustively and\nwith precision.\n\nBut in order to discover such a principle, I looked about for an act\nof the understanding which comprises all the rest, and is\ndistinguished only by various modifications or phases, in reducing the\nmultiplicity of representation to the unity of thinking in general: I\nfound this act of the understanding to consist in judging. Here then\nthe labors of the logicians were ready at hand, though not yet quite\nfree from defects, and with this help I was enabled to exhibit a\ncomplete table of the pure functions of the understanding, which are\nhowever undetermined in regard to any object. I finally referred these\nfunctions of judging to objects in general, or rather to the condition\nof determining judgments as objectively valid, and so there arose the\npure concepts of the understanding, concerning which I could make\ncertain, that these, and this exact number only, constitute our whole\ncognition of things from pure understanding. I was justified in\ncalling them by their old name, Categories, while I reserved for\nmyself the liberty of adding, under the title of \"Predicables,\" a\ncomplete list of all the concepts deducible from them, by combinations\nwhether among themselves, or with the pure form of the appearance,\ni.e., space or time, or with its matter, so far as it is not yet\nempirically determined (viz., the object of sensation in general), as\nsoon as a system of transcendental philosophy should be completed with\nthe construction of which I am engaged in the Critique of Pure Reason\nitself.\n\nNow the essential point in this system of Categories, which\ndistinguishes it from the old rhapsodical collection without any\nprinciple, and for which alone it deserves to be considered as\nphilosophy, consists in this: that by means of it the true\nsignificance of the pure concepts of the understanding and the\ncondition of their use could be precisely determined. For here it\nbecame obvious that they are themselves nothing but logical functions,\nand as such do not produce the least concept of an object, but require\nsome sensuous intuition as a basis. They therefore only serve to\ndetermine empirical judgments, which are otherwise undetermined and\nindifferent as regards all functions of judging, relatively to these\nfunctions, thereby procuring them universal validity, and by means of\nthem making judgments of experience in general possible.\n\nSuch an insight into the nature of the categories, which limits them\nat the same time to the mere use of experience, never occurred either\nto their first author, or to any of his successors; but without this\ninsight (which immediately depends upon their derivation or\ndeduction), they are quite useless and only a miserable list of names,\nwithout explanation or rule for their use. Had the ancients ever\nconceived such a notion, doubtless the whole study of the pure\nrational knowledge, which under the name of metaphysics has for\ncenturies spoiled many a sound mind, would have reached us in quite\nanother shape, and would have enlightened the human understanding,\ninstead of actually exhausting it in obscure and vain speculations,\nthereby rendering it unfit for true science.\n\nThis system of categories makes all treatment of every object of pure\nreason itself systematic, and affords a direction or clue how and\nthrough what points of inquiry every metaphysical consideration must\nproceed, in order to be complete; for it exhausts all the possible\nmovements (momenta) of the understanding, among which every concept\nmust be classed. In like manner the table of Principles has been\nformulated, the completeness of which we can only vouch for by the\nsystem of the categories. Even in the division of the concepts,{25}\nwhich must go beyond the physical application of the understanding, it\nis always the very same clue, which, as it must always be determined a\npriori by the same fixed points of the human understanding, always\nforms a closed circle. There is no doubt that the object of a pure\nconception either of the understanding or of reason, so far as it is\nto be estimated philosophically and on a priori principles, can in\nthis way be completely cognised. I could not therefore omit to make\nuse of this clue with regard to one of the most abstract ontological\ndivisions, viz., the various distinctions of \"the notions of something\nand of nothing,\" and to construct accordingly (Critique, p.\u00a0207) a\nregular and necessary table of their divisions.{26}\n\n===================================\n{25} See the two tables in the chapters Von den Paralogismen der reinen\nVernuuft and the first division of the Antinomy of Pure Reason, System\nder kosmologischen Ideen.\n\n{26} On the table of the categories many neat observations may be made,\nfor instance: (1) that the third arises from the first and the second\njoined in one concept; (2) that in those of Quantity and of Quality\nthere is merely a progress from unity to totality or from something to\nnothing (for this purpose the categories of Quality must stand thus:\nreality, limitation, total negation), without correlata or opposita,\nwhereas those of Relation and of Modality have them; (3) that, as in\nLogic categorical judgments are the basis of all others, so the\ncategory of Substance is the basis of all concepts of actual things;\n(4) that as Modality in the judgment is not a particular predicate, so\nby the modal concepts a determination is not superadded to things,\netc., etc. Such observations are of great use. If we besides enumerate\nall the predicables, which we can find pretty completely in any good\nontology (for example, Baumgarten's), and arrange them in classes\nunder the categories, in which operation we must not neglect to add as\ncomplete a dissection of all these concepts as possible, there will\nthen arise a merely analytical part of metaphysics, which does not\ncontain a single synthetical proposition, which might precede the\nsecond (the synthetical), and would by its precision and completeness\nbe not only useful, but, in virtue of its system, be even to some\nextent elegant.\n===================================\n\nAnd this system, like every other true one founded on a universal\nprinciple, shows its inestimable value in this, that it excludes all\nforeign concepts, which might otherwise intrude among the pure\nconcepts of the understanding, and determines the place of every\ncognition. Those concepts, which under the name of \"concepts of\nreflexion\" have been likewise arranged in a table according to the\nclue of the categories, intrude, without having any privilege or title\nto be among the pure concepts of the understanding in Ontology. They\nare concepts of connexion, and thereby of the objects themselves,\nwhereas the former are only concepts of a mere comparison of concepts\nalready given, hence of quite another nature and use. By my systematic\ndivision{27} they are saved from this confusion. But the value of my\nspecial table of the categories will be still more obvious, when we\nseparate the table of the transcendental concepts of Reason from the\nconcepts of the understanding. The latter being of quite another\nnature and origin, they must have quite another form than the former.\nThis so necessary separation has never yet been made in any system of\nmetaphysics for, as a rule, these rational concepts all mixed up with\nthe categories, like children of one family, which confusion was\nunavoidable in the absence of a definite system of categories.\n\n===================================\n{27} See Critique of Pure Reason, Von der Amphibolie der Reflexbegriffe.\n===================================\n\nTHIRD PART OF THE MAIN TRANSCENDENTAL PROBLEM.\n\nHOW IS METAPHYSICS IN GENERAL POSSIBLE?\n\n\u00a7\u00a040.\n\nPure mathematics and pure science of nature had no occasion for such a\ndeduction, as we have made of both, for their own safety and\ncertainty. For the former rests upon its own evidence; and the latter\n(though sprung from pure sources of the understanding) upon experience\nand its thorough confirmation. Physics cannot altogether refuse and\ndispense with the testimony of the latter; because with all its\ncertainty, it can never, as philosophy, rival mathematics. Both\nsciences therefore stood in need of this inquiry, not for themselves,\nbut for the sake of another science, metaphysics.\n\nMetaphysics has to do not only with concepts of nature, which always\nfind their application in experience, but also with pure rational\nconcepts, which never can be given in any possible experience.\nConsequently the objective reality of these concepts (viz., that they\nare not mere chimeras), and the truth or falsity of metaphysical\nassertions, cannot be discovered or confirmed by any experience. This\npart of metaphysics however is precisely what constitutes its\nessential end, to which the rest is only a means, and thus this\nscience is in need of such a deduction for its own sake. The third\nquestion now proposed relates therefore as it were to the root and\nessential difference of metaphysics, i.e., the occupation of Reason\nwith itself, and the supposed knowledge of objects arising immediately\nfrom this incubation of its own concepts, without requiring, or indeed\nbeing able to reach that knowledge through, experience.{28}\n\n===================================\n{28} If we can say, that a science is actual at least in the ideas of\nall men, as soon as it appears that the problems which lead to it are\nproposed to everybody by the nature of human reason, and that\ntherefore many (though faulty) endeavors are unavoidably made in its\nbehalf, then we are bound to say that metaphysics is subjectively (and\nindeed necessarily) actual, and therefore we justly ask, how is it\n(objectively) possible.\n===================================\n\nWithout solving this problem reason never is justified. The empirical\nuse to which reason limits the pure understanding, does not fully\nsatisfy the proper destination of the latter. Every single experience\nis only a part of the whole sphere of its domain, but the absolute\ntotality of all possible experience is itself not experience. Yet it\nis a necessary [concrete] problem for reason, the mere representation\nof which requires concepts quite different from the categories, whose\nuse is only immanent, or refers to experience, so far as it can be\ngiven. Whereas the concepts of reason aim at the completeness, i.e.,\nthe collective unity of all possible experience, and thereby transcend\nevery given experience. Thus they become transcendent.\n\nAs the understanding stands in need of categories for experience,\nreason contains in itself the source of ideas, by which I mean\nnecessary concepts, whose object cannot be given in any experience.\nThe latter are inherent in the nature of reason, as the former are in\nthat of the understanding. While the former carry with them an\nillusion likely to mislead, the illusion of the latter is inevitable,\nthough it certainly can be kept from misleading us.\n\nSince all illusion consists in holding the subjective ground of our\njudgments to be objective, a self-knowledge of pure reason in its\ntranscendent (exaggerated) use is the sole preservative from the\naberrations into which reason falls when it mistakes its destination,\nand refers that to the object transcendently, which only regards its\nown subject and its guidance in all immanent use.\n\n\u00a7 41. The distinction of ideas, that is, of pure concepts of reason,\nfrom categories, or pure concepts of the understanding, as cognitions\nof a quite distinct species, origin and use, is so important a point\nin founding a science which is to contain the system of all these a\npriori cognitions, that without this distinction metaphysics is\nabsolutely impossible, or is at best a random, bungling attempt to\nbuild a castle in the air without a knowledge of the materials or of\ntheir fitness for any purpose. Had the Critique of Pure Reason done\nnothing but first point out this distinction, it had thereby\ncontributed more to clear up our conception of, and to guide our\ninquiry in, the field of metaphysics, than all the vain efforts which\nhave hitherto been made to satisfy the transcendent problems of pure\nreason, without ever surmising that we were in quite another field\nthan that of the understanding, and hence classing concepts of the\nunderstanding and those of reason together, as if they were of the\nsame kind.\n\n\u00a7 42. All pure cognitions of the understanding have this feature,\nthat their concepts present themselves in experience, and their\nprinciples can be confirmed by it; whereas the transcendent cognitions\nof reason cannot, either as ideas, appear in experience, or as\npropositions ever be confirmed or refuted by it. Hence whatever errors\nmay slip in unawares, can only be discovered by pure reason itself\u2014a\ndiscovery of much difficulty, because this very reason naturally\nbecomes dialectical by means of its ideas, and this unavoidable\nillusion cannot be limited by any objective and dogmatical researches\ninto things, but by a subjective investigation of reason itself as a\nsource of ideas.\n\n\u00a7 43. In the Critique of Pure Reason it was always my greatest care\nto endeavor not only carefully to distinguish the several species of\ncognition, but to derive concepts belonging to each one of them from\ntheir common source. I did this in order that by knowing whence they\noriginated, I might determine their use with safety, and also have the\nunanticipated but invaluable advantage of knowing the completeness of\nmy enumeration, classification and specification of concepts a priori,\nand therefore according to principles. Without this, metaphysics is\nmere rhapsody, in which no one knows whether he has enough, or whether\nand where something is still wanting. We can indeed have this\nadvantage only in pure philosophy, but of this philosophy it\nconstitutes the very essence.\n\nAs I had found the origin of the categories in the four logical\nfunctions of all the judgments of the understanding, it was quite\nnatural to seek the origin of the ideas in the three functions of the\nsyllogisms of reason. For as soon as these pure concepts of reason\n(the transcendental ideas) are given, they could hardly, except they\nbe held innate, be found anywhere else, than in the same activity of\nreason, which, so far as it regards mere form, constitutes the logical\nelement of the syllogisms of reason; but, so far as it represents\njudgments of the understanding with respect to the one or to the other\nform a priori, constitutes transcendental concepts of pure reason.\n\nThe formal distinction of syllogisms renders their division into\ncategorical, hypothetical, and disjunctive necessary. The concepts of\nreason founded on them contained therefore, first, the idea of the\ncomplete subject (the substantial); secondly, the idea of the complete\nseries of conditions; thirdly, the determination of all concepts in\nthe idea of a complete complex of that which is possible.{29} The first\nidea is psychological, the second cosmological, the third theological,\nand, as all three give occasion to Dialectics, yet each in its own\nway, the division of the whole Dialects of pure reason into its\nParalogism, its Antinomy, and its Ideal, was arranged accordingly.\nThrough this deduction we may feel assured that all the claims of pure\nreason are completely represented, and that none can be wanting;\nbecause the faculty of reason itself, whence they all take their\norigin, is thereby completely surveyed.\n\n===================================\n{29} In disjunctive judgments we consider all possibility as divided in\nrespect to a particular concept. By the ontological principle of the\nuniversal determination of a thing in general, I understand the\nprinciple that either the one or the other of all possible\ncontradictory predicates must be assigned to any object. This is at\nthe same time the principle of all disjunctive judgments, constituting\nthe foundation of our conception of possibility, and in it the\npossibility of every object in general is considered as determined.\nThis may serve as a slight explanation of the above proposition: that\nthe activity of reason in disjunctive syllogisms is formally the same\nas that by which it fashions the idea of a universal conception of all\nreality, containing in itself that which is positive in all\ncontradictory predicates.\n===================================\n\n\u00a7 44. In these general considerations it is also remarkable that the\nideas of reason are unlike the categories, of no service to the use of\nour understanding in experience, but quite dispensable, and become\neven an impediment to the maxims of a rational cognition of nature.\nYet in another aspect still to be determined they are necessary.\nWhether the soul is or is not a simple substance, is of no consequence\nto us in the explanation of its phenomena. For we cannot render the\nnotion of a simple being intelligible by any possible experience that\nis sensuous or concrete. The notion is therefore quite void as regards\nall hoped-for insight into the cause of phenomena, and cannot at all\nserve as a principle of the explanation of that which internal or\nexternal experience supplies. So the cosmological ideas of the\nbeginning of the world or of its eternity (a parte ante) cannot be of\nany greater service to us for the explanation of any event in the\nworld itself. And finally we must, according to a right maxim of the\nphilosophy of nature, refrain from all explanations of the design of\nnature, drawn from the will of a Supreme Being; because this would not\nbe natural philosophy, but an acknowledgment that we have come to the\nend of it. The use of these ideas, therefore, is quite different from\nthat of those categories by which (and by the principles built upon\nwhich) experience itself first becomes possible. But our laborious\nanalytics of the understanding would be superfluous if we had nothing\nelse in view than the mere cognition of nature as it can be given in\nexperience; for reason does its work, both in mathematics and in the\nscience of nature, quite safely and well without any of this subtle\ndeduction. Therefore our Critique of the Understanding combines with\nthe ideas of pure reason for a purpose which lies beyond the empirical\nuse of the understanding; but this we have above declared to be in\nthis aspect totally inadmissible, and without any object or meaning.\nYet there must be a harmony between that of the nature of reason and\nthat of the understanding, and the former must contribute to the\nperfection of the latter, and cannot possibly upset it.\n\nThe solution of this question is as follows: Pure reason does not in\nits ideas point to particular objects, which lie beyond the field of\nexperience, but only requires completeness of the use of the\nunderstanding in the system of experience. But this completeness can\nbe a completeness of principles only, not of intuitions (i.e.,\nconcrete atsights or Anschauungen) and of objects. In order however to\nrepresent the ideas definitely, reason conceives them after the\nfashion of the cognition of an object. The cognition is as far as\nthese rules are concerned completely determined, but the object is\nonly an idea invented for the purpose of bringing the cognition of the\nunderstanding as near as possible to the completeness represented by\nthat idea.\n\nPrefatory Remark to the Dialectics of Pure Reason.\n\n\u00a7 45. We have above shown in \u00a7\u00a7 33 and 34 that the purity of the\ncategories from all admixture of sensuous determinations may mislead\nreason into extending their use, quite beyond all experience, to\nthings in themselves; though as these categories themselves find no\nintuition which can give them meaning or sense in concreto, they, as\nmere logical functions, can represent a thing in general, but not give\nby themselves alone a determinate concept of anything. Such\nhyperbolical objects are distinguised by the appellation of No\u00fcmena,\nor pure beings of the understanding (or better, beings of thought),\nsuch as, for example, \"substance,\" but conceived without permanence in\ntime, or \"cause,\" but not acting in time, etc. Here predicates, that\nonly serve to make the conformity-to-law of experience possible, are\napplied to these concepts, and yet they are deprived of all the\nconditions of intuition, on which alone experience is possible, and so\nthese concepts lose all significance.\n\nThere is no danger, however, of the understanding spontaneously making\nan excursion so very wantonly beyond its own bounds into the field of\nthe mere creatures of thought, without being impelled by foreign laws.\nBut when reason, which cannot be fully satisfied with any empirical\nuse of the rules of the understanding, as being always conditioned,\nrequires a completion of this chain of conditions, then the\nunderstanding is forced out of its sphere. And then it partly\nrepresents objects of experience in a series so extended that no\nexperience can grasp, partly even (with a view to complete the series)\nit seeks entirely beyond it noumena, to which it can attach that\nchain, and so, having at last escaped from the conditions of\nexperience, make its attitude as it were final. These are then the\ntranscendental ideas, which, though according to the true but hidden\nends of the natural determination of our reason, they may aim not at\nextravagant concepts, but at an unbounded extension of their empirical\nuse, yet seduce the understanding by an unavoidable illusion to a\ntranscendent use, which, though deceitful, cannot be restrained within\nthe bounds of experience by any resolution, but only by scientific\ninstruction and with much difficulty.\n\nI. The Psychological Idea.{30}\n\n===================================\n{30} See Critique of Pure Reason, Von den Paralogismen der reinen\nVernunft.\n===================================\n\n\u00a7 46. People have long since observed, that in all substances the\nproper subject, that which remains after all the accidents (as\npredicates) are abstracted, consequently that which forms the\nsubstance of things remains unknown, and various complaints have been\nmade concerning these limits to our knowledge. But it will be well to\nconsider that the human understanding is not to be blamed for its\ninability to know the substance of things, that is, to determine it by\nitself, but rather for requiring to cognise it which is a mere idea\ndefinitely as though it were a given object. Pure reason requires us\nto seek for every predicate of a thing its proper subject, and for\nthis subject, which is itself necessarily nothing but a predicate, its\nsubject, and so on indefinitely (or as far as we can reach). But hence\nit follows, that we must not hold anything, at which we can arrive, to\nbe an ultimate subject, and that substance itself never can be thought\nby our understanding, however deep we may penetrate, even if all\nnature were unveiled to us. For the specific nature of our\nunderstanding consists in thinking everything discursively, that is,\nrepresenting it by concepts, and so by mere predicates, to which\ntherefore the absolute subject must always be wanting. Hence all the\nreal properties, by which we cognise bodies, are mere accidents, not\nexcepting impenetrability, which we can only represent to ourselves as\nthe effect of a power of which the subject is unknown to us.\n\nNow we appear to have this substance in the consciousness of ourselves\n(in the thinking subject), and indeed in an immediate intuition; for\nall the predicates of an internal sense refer to the ego, as a\nsubject, and I cannot conceive myself as the predicate of any other\nsubject. Hence completeness in the reference of the given concepts as\npredicates to a subject\u2014not merely an idea, but an object\u2014that is,\nthe absolute subject itself, seems to be given in experience. But this\nexpectation is disappointed. For the ego is not a concept,{31} but only\nthe indication of the object of the internal sense, so far as we\ncognise it by no further predicate. Consequently it cannot be in\nitself a predicate of any other thing; but just as little can it be a\ndeterminate concept of an absolute subject, but is, as in all other\ncases, only the reference of the internal phenomena to their unknown\nsubject. Yet this idea (which serves very well, as a regulative\nprinciple, totally to destroy all materialistic explanations of the\ninternal phenomena of the soul) occasions by a very natural\nmisunderstanding a very specious argument, which, from this supposed\ncognition of the substance of our thinking being, infers its nature,\nso far as the knowledge of it falls quite without the complex of\nexperience.\n\n===================================\n{31} Were the representation of the apperception (the Ego) a concept, by\nwhich anything could be thought, it could be used as a predicate of\nother things or contain predicates in itself. But it is nothing more\nthan the feeling of an existence without the least definite conception\nand is only the representation of that to which all thinking stands in\nrelation (relatione accidentis).\n===================================\n\n\u00a7 47. But though we may call this thinking self (the soul) substance,\nas being the ultimate subject of thinking which cannot be further\nrepresented as the predicate of another thing; it remains quite empty\nand without significance, if permanence\u2014the quality which renders\nthe concept of substances in experience fruitful\u2014cannot be proved of\nit.\n\nBut permanence can never be proved of the concept of a substance, as a\nthing in itself, but for the purposes of experience only. This is\nsufficiently shown by the first Analogy of Experience,{32} and who ever\nwill not yield to this proof may try for himself whether he can\nsucceed in proving, from the concept of a subject which does not exist\nitself as the predicate of another thing, that its existence is\nthoroughly permanent, and that it cannot either in itself or by any\nnatural cause originate or be annihilated. These synthetical a priori\npropositions can never be proved in themselves, but only in reference\nto things as objects of possible experience.\n\n===================================\n{32} Cf. Critique, Von den Analogien der Erfahrung.\n===================================\n\n\u00a7 48. If therefore from the concept of the soul as a substance, we\nwould infer its permanence, this can hold good as regards possible\nexperience only, not [of the soul] as a thing in itself and beyond all\npossible experience. But life is the subjective condition of all our\npossible experience, consequently we can only infer the permanence of\nthe soul in life; for the death of man is the end of all experience\nwhich concerns the soul as an object of experience, except the\ncontrary be proved, which is the very question in hand. The permanence\nof the soul can therefore only be proved (and no one cares for that)\nduring the life of man, but not, as we desire to do, after death; and\nfor this general reason, that the concept of substance, so far as it\nis to be considered necessarily combined with the concept of\npermanence, can be so combined only according to the principles of\npossible experience, and therefore for the purposes of experience\nonly.{33}\n\n===================================\n{33} It is indeed very remarkable how carelessly metaphysicians have\nalways passed over the principle of the permanence of substances\nwithout ever attempting a proof of it; doubtless because they found\nthemselves abandoned by all proofs as soon as they began to deal with\nthe concept of substance. Common sense, which felt distinctly that\nwithout this presupposition do union of perceptions in experience is\npossible, supplied the want by a postulate. From experience itself it\nnever could derive such a principle, partly because substances cannot\nbe so traced in all their alterations and dissolutions, that the\nmatter can always be found undiminished, partly because the principle\ncontains necessity, which is always the sign of an a priori principle.\nPeople then boldly applied this postulate to the concept of soul as a\nsubstance, and concluded a necessary continuance of the soul after the\ndeath of man (especially as the simplicity of this substance, which is\ninferred from the indivisibility of consciousness, secured it from\ndestruction by dissolution). Had they found the genuine source of this\nprinciple\u2014a discovery which requires deeper researches than they\nwere ever inclined to make\u2014they would have seen, that the law of the\npermanence of substances has place for the purposes of experience\nonly, and hence can hold good of things so far as they are to be\ncognised and conjoined with others in experience, but never\nindependently of all possible experience, and consequently cannot hold\ngood of the soul after death.\n===================================\n\n\u00a7\u00a049. That there is something real without us which not only\ncorresponds, but must correspond, to our external perceptions, can\nlikewise be proved to be not a connexion of things in themselves, but\nfor the sake of experience. This means that there is something\nempirical, i.e., some phenomenon in space without us, that admits of a\nsatisfactory proof, for we have nothing to do with other objects than\nthose which belong to possible experience; because objects which\ncannot be given us in any experience, do not exist for us. Empirically\nwithout me is that which appears in space, and space, together with\nall the phenomena which it contains, belongs to the representations,\nwhose connexion according to laws of experience proves their objective\ntruth, just as the connexion of the phenomena of the internal sense\nproves the actuality of my soul (as an object of the internal sense).\nBy means of external experience I am conscious of the actuality of\nbodies, as external phenomena in space, in the same manner as by means\nof the internal experience I am conscious of the existence of my soul\nin time, but this soul is only cognised as an object of the internal\nsense by phenomena that constitute an internal state, and of which the\nessence in itself, which forms the basis of these phenomena, is\nunknown. Cartesian idealism therefore does nothing but distinguish\nexternal experience from dreaming; and the conformity to law (as a\ncriterion of its truth) of the former, from the irregularity and the\nfalse illusion of the latter. In both it presupposes space and time as\nconditions of the existence of objects, and it only inquires whether\nthe objects of the external senses, which we when awake put in space,\nare as actually to be found in it, as the object of the internal\nsense, the soul, is in time; that is, whether experience carries with\nit sure criteria to distinguish it from imagination. This doubt,\nhowever, may be easily disposed of, and we always do so in common life\nby investigating the connexion of phenomena in both space and time\naccording to universal laws of experience, and we cannot doubt, when\nthe representation of external things throughout agrees therewith,\nthat they constitute truthful experience. Material idealism, in which\nphenomena are considered as such only according to their connexion in\nexperience, may accordingly be very easily refuted; and it is just as\nsure an experience, that bodies exist without us (in space), as that I\nmyself exist according to the representation of the internal sense (in\ntime): for the notion without us, only signifies existence in space.\nHowever as the Ego in the proposition, \"I am,\" means not only the\nobject of internal intuition (in time), but the subject of\nconsciousness, just as body means not only external intuition (in\nspace), but the thing-in-itself, which is the basis of this\nphenomenon; [as this is the case] the question, whether bodies (as\nphenomena of the external sense) exist as bodies apart from my\nthoughts, may without any hesitation be denied in nature. But the\nquestion, whether I myself as a phenomenon of the internal sense (the\nsoul according to empirical psychology) exist apart from my faculty of\nrepresentation in time, is an exactly similar inquiry, and must\nlikewise be answered in the negative. And in this manner everything,\nwhen it is reduced to its true meaning, is decided and certain. The\nformal (which I have also called transcendental) actually abolishes\nthe material, or Cartesian, idealism. For if space be nothing but a\nform of my sensibility, it is as a representation in me just as actual\nas I myself am, and nothing but the empirical truth of the\nrepresentations in it remains for consideration. But, if this is not\nthe case, if space and the phenomena in it are something existing\nwithout us, then all the criteria of experience beyond our perception\ncan never prove the actuality of these objects without us.\n\nII. The Cosmological Idea.{34}\n\n===================================\n{34} Cf. Critique, Die Antinomie der reinen Vernunft.\n===================================\n\n\u00a7 50. This product of pure reason in its transcendent use is its most\nremarkable curiosity. It serves as a very powerful agent to rouse\nphilosophy from its dogmatic slumber, and to stimulate it to the\narduous task of undertaking a Critique of Reason itself.\n\nI term this idea cosmological, because it always takes its object only\nfrom the sensible world, and does not use any other than those whose\nobject is given to sense, consequently it remains in this respect in\nits native home, it does not become transcendent, and is therefore so\nfar not mere idea; whereas, to conceive the soul as a simple\nsubstance, already means to conceive such an object (the simple) as\ncannot be presented to the senses. Yet the cosmological idea extends\nthe connexion of the conditioned with its condition (whether the\nconnexion is mathematical or dynamical) so far, that experience never\ncan keep up with it. It is therefore with regard to this point always\nan idea, whose object never can be adequately given in any experience.\n\n\u00a7 51. In the first place, the use of a system of categories becomes\nhere so obvious and unmistakable, that even if there were not several\nother proofs of it, this alone would sufficiently prove it\nindispensable in the system of pure reason. There are only four such\ntranscendent ideas, as there are so many classes of categories; in\neach of which, however, they refer only to the absolute completeness\nof the series of the conditions for a given conditioned. In analogy to\nthese cosmological ideas there are only four kinds of dialectical\nassertions of pure reason, which, as they are dialectical, thereby\nprove, that to each of them, on equally specious principles of pure\nreason, a contradictory assertion stands opposed. As all the\nmetaphysical art of the most subtile distinction cannot prevent this\nopposition, it compels the philosopher to recur to the first sources\nof pure reason itself. This Antinomy, not arbitrarily invented, but\nfounded in the nature of human reason, and hence unavoidable and never\nceasing, contains the following four theses together with their\nantitheses:\n\n\n                             1.\n\n                           Thesis.\n    The World has, as to Time and Space, a Beginning (limit).\n\n                         Antithesis.\n       The World is, as to Time and Space, infinite.\n\n                             2.\n\n                           Thesis.\n  Everything in the World consists of [elements that are] simple.\n\n                         Antithesis.\n      There is nothing simple, but everything is composite.\n\n                             3.\n\n                           Thesis.\n      There are in the World Causes through Freedom.\n\n                         Antithesis.\n          There is no Liberty, but all is Nature.\n\n                             4.\n\n                           Thesis.\n   In the Series of the World-Causes there is some necessary Being.\n\n                         Antithesis.\nThere is Nothing necessary in the World, but in this Series All is\n                         incidental.\n\n\n\u00a7 52.a. Here is the most singular phenomenon of human reason, no\nother instance of which can be shown in any other use. If we, as is\ncommonly done, represent to ourselves the appearances of the sensible\nworld as things in themselves, if we assume the principles of their\ncombination as principles universally valid of things in themselves\nand not merely of experience, as is usually, nay without our Critique,\nunavoidably done, there arises an unexpected conflict, which never can\nbe removed in the common dogmatical way; because the thesis, as well\nas the antithesis, can be shown by equally clear, evident, and\nirresistible proofs\u2014for I pledge myself as to the correctness of all\nthese proofs\u2014and reason therefore perceives that it is divided with\nitself, a state at which the sceptic rejoices, but which must make the\ncritical philosopher pause and feel ill at ease.\n\n\u00a7 52.b. We may blunder in various ways in metaphysics without any\nfear of being detected in falsehood. For we never can be refuted by\nexperience if we but avoid self-contradiction, which in synthetical,\nthough purely fictitious propositions, may be done whenever the\nconcepts, which we connect, are mere ideas, that cannot be given (in\ntheir whole content) in experience. For how can we make out by\nexperience, whether the world is from eternity or had a beginning,\nwhether matter is infinitely divisible or consists of simple parts?\nSuch concept cannot be given in any experience, be it ever so\nextensive, and consequently the falsehood either of the positive or\nthe negative proposition cannot be discovered by this touch-stone.\n\nThe only possible way in which reason could have revealed\nunintentionally its secret Dialectics, falsely announced as Dogmatics,\nwould be when it were made to ground an assertion upon a universally\nadmitted principle, and to deduce the exact contrary with the greatest\naccuracy of inference from another which is equally granted. This is\nactually here the case with regard to four natural ideas of reason,\nwhence four assertions on the one side, and as many counter-assertions\non the other arise, each consistently following from\nuniversally-acknowledged principles. Thus they reveal by the use of\nthese principles the dialectical illusion of pure reason which would\notherwise forever remain concealed.\n\nThis is therefore a decisive experiment, which must necessarily expose\nany error lying hidden in the assumptions of reason.{35} Contradictory\npropositions cannot both be false, except the concept, which is the\nsubject of both, is self-contradictory; for example, the propositions,\n\"a square circle is round, and a square circle is not round,\" are both\nfalse. For, as to the former it is false, that the circle is round,\nbecause it is quadrangular; and it is likewise false, that it is not\nround, that is, angular, because it is a circle. For the logical\ncriterion of the impossibility of a concept consists in this, that if\nwe presuppose it, two contradictory propositions both become false;\nconsequently, as no middle between them is conceivable, nothing at all\nis thought by that concept.\n\n===================================\n{35} I therefore would be pleased to have the critical reader to devote\nto this antinomy of pure reason his chief attention, because nature\nitself seems to have established it with a view to stagger reason in\nits daring pretentions, and to force it to self-examination. For every\nproof, which I have given, as well of the thesis as of the antithesis,\nI undertake to be responsible, and thereby to show the certainty of\nthe inevitable antinomy of reason. When the reader is brought by this\ncurious phenomenon to fall back upon the proof of the presumption upon\nwhich it rests, he will feel himself obliged to investigate the\nultimate foundation of all the cognition of pure reason with me more\nthoroughly.\n===================================\n\n\u00a7 52.c. The first two antinomies, which I call mathematical, because\nthey are concerned with the addition or division of the homogeneous,\nare founded on such a self-contradictory concept; and hence I explain\nhow it happens, that both the Thesis and Antithesis of the two are\nfalse.\n\nWhen I speak of objects in time and in space, it is not of things in\nthemselves, of which I know nothing, but of things in appearance, that\nis, of experience, as the particular way of cognising objects which is\nafforded to man. I must not say of what I think in time or in space,\nthat in itself, and independent of these my thoughts, it exists in\nspace and in time; for in that case I should contradict myself;\nbecause space and time, together with the appearances in them, are\nnothing existing in themselves and outside of my representations, but\nare themselves only modes of representation, and it is palpably\ncontradictory to say, that a mere mode of representation exists\nwithout our representation. Objects of the senses therefore exist only\nin experience; whereas to give them a self-subsisting existence apart\nfrom experience or before it, is merely to represent to ourselves that\nexperience actually exists apart from experience or before it.\n\nNow if I inquire after the quantity of the world, as to space and\ntime, it is equally impossible, as regards all my notions, to declare\nit infinite or to declare it finite. For neither assertion can be\ncontained in experience, because experience either of an infinite\nspace, or of an infinite time elapsed, or again, of the boundary of\nthe world by a void space, or by an antecedent void time, is\nimpossible; these are mere ideas. This quantity of the world, which is\ndetermined in either way, should therefore exist in the world itself\napart from all experience. This contradicts the notion of a world of\nsense, which is merely a complex of the appearances whose existence\nand connexion occur only in our representations, that is, in\nexperience, since this latter is not an object in itself, but a mere\nmode of representation. Hence it follows, that as the concept of an\nabsolutely existing world of sense is self-contradictory, the solution\nof the problem concerning its quantity, whether attempted\naffirmatively or negatively, is always false.\n\nThe same holds good of the second antinomy, which relates to the\ndivision of phenomena. For these are mere representations, and the\nparts exist merely in their representation, consequently in the\ndivision, or in a possible experience where they are given, and the\ndivision reaches only as far as this latter reaches. To assume that an\nappearance, e.g., that of body, contains in itself before all\nexperience all the parts, which any possible experience can ever\nreach, is to impute to a mere appearance, which can exist only in\nexperience, an existence previous to experience. In other words, it\nwould mean that mere representations exist before they can be found in\nour faculty of representation. Such an assertion is\nself-contradictory, as also every solution of our misunderstood\nproblem, whether we maintain, that bodies in themselves consist of an\ninfinite number of parts, or of a finite number of simple parts.\n\n\u00a7 53. In the first (the mathematical) class of antinomies the\nfalsehood of the assumption consists in representing in one concept\nsomething self-contradictory as if it were compatible (i.e., an\nappearance as an object in itself). But, as to the second (the\ndynamical) class of antinomies, the falsehood of the representation\nconsists in representing as contradictory what is compatible; so that,\nas in the former case, the opposed assertions are both false, in this\ncase, on the other hand, where they are opposed to one another by mere\nmisunderstanding, they may both be true.\n\nAny mathematical connexion necessarily presupposes homogeneity of what\nis connected (in the concept of magnitude), while the dynamical one by\nno means requires the same. When we have to deal with extended\nmagnitudes, all the parts must be homogeneous with one another and\nwith the whole; whereas, in the connexion of cause and effect,\nhomogeneity may indeed likewise be found, but is not necessary; for\nthe concept of causality (by means of which something is posited\nthrough something else quite different from it), at all events, does\nnot require it.\n\nIf the objects of the world of sense are taken for things in\nthemselves, and the above laws of nature for the laws of things in\nthemselves, the contradiction would be unavoidable. So also, if the\nsubject of freedom were, like other objects, represented as mere\nappearance, the contradiction would be just as unavoidable, for the\nsame predicate would at once be affirmed and denied of the same kind\nof object in the same sense. But if natural necessity is referred\nmerely to appearances, and freedom merely to things in themselves, no\ncontradiction arises, if we at once assume, or admit both kinds of\ncausality, however difficult or impossible it may be to make the\nlatter kind conceivable.\n\nAs appearance every effect is an event, or something that happens in\ntime; it must, according to the universal law of nature, be preceded\nby a determination of the causality of its cause (a state), which\nfollows according to a constant law. But this determination of the\ncause as causality must likewise be something that takes place or\nhappens; the cause must have begun to act, otherwise no succession\nbetween it and the effect could be conceived. Otherwise the effect, as\nwell as the causality of the cause, would have always existed.\nTherefore the determination of the cause to act must also have\noriginated among appearances, and must consequently, as well as its\neffect, be an event, which must again have its cause, and so on; hence\nnatural necessity must be the condition, on which effective causes are\ndetermined. Whereas if freedom is to be a property of certain causes\nof appearances, it must, as regards these, which are events, be a\nfaculty of starting them spontaneously, that is, without the causality\nof the cause itself, and hence without requiring any other ground to\ndetermine its start. But then the cause, as to its causality, must not\nrank under time-determinations of its state, that is, it cannot be an\nappearance, and must be considered a thing in itself, while its\neffects would be only appearances.{36} If without contradiction we can\nthink of the beings of understanding [Verstandeswesen] as exercising\nsuch an influence on appearances, then natural necessity will attach\nto all connexions of cause and effect in the sensuous world, though on\nthe other hand, freedom can be granted to such cause, as is itself not\nan appearance (but the foundation of appearance). Nature therefore and\nfreedom can without contradiction be attributed to the very same\nthing, but in different relations\u2014on one side as a phenomenon, on\nthe other as a thing in itself.\n\n===================================\n{36} The idea of freedom occurs only in the relation of the\nintellectual, as cause, to the appearance, as effect. Hence we cannot\nattribute freedom to matter in regard to the incessant action by which\nit fills its space, though this action takes place from an internal\nprinciple. We can likewise find no notion of freedom suitable to\npurely rational beings, for instance, to God, so far as his action is\nimmanent. For his action, though independent of external determining\ncauses, is determined in his eternal reason, that is, in the divine\nnature. It is only, if something is to start by an action, and so the\neffect occurs in the sequence of time, or in the world of sense (e.g.,\nthe beginning of the world), that we can put the question, whether the\ncausality of the cause must in its turn have been started, or whether\nthe cause can originate an effect without its causality itself\nbeginning. In the former case the concept of this causality is a\nconcept of natural necessity, in the latter, that of freedom. From\nthis the reader will see, that, as I explained freedom to be the\nfaculty of starting an event spontaneously, I have exactly hit the\nnotion which is the problem of metaphysics.\n===================================\n\nWe have in us a faculty, which not only stands in connexion with its\nsubjective determining grounds that are the natural causes of its\nactions, and is so far the faculty of a being that itself belongs to\nappearances, but is also referred to objective grounds, that are only\nideas, so far as they can determine this faculty, a connexion which is\nexpressed by the word ought. This faculty is called reason, and, so\nfar as we consider a being (man) entirely according to this\nobjectively determinable reason, he cannot be considered as a being of\nsense, but this property is that of a thing in itself, of which we\ncannot comprehend the possibility\u2014I mean how the ought (which\nhowever has never yet taken place) should determine its activity, and\ncan become the cause of actions, whose effect is an appearance in the\nsensible world. Yet the causality of reason would be freedom with\nregard to the effects in the sensuous world, so far as we can consider\nobjective grounds, which are themselves ideas, as their determinants.\nFor its action in that case would not depend upon subjective\nconditions, consequently not upon those of time, and of course not\nupon the law of nature, which serves to determine them, because\ngrounds of reason give to actions the rule universally, according to\nprinciples, without the influence of the circumstances of either time\nor place.\n\nWhat I adduce here is merely meant as an example to make the thing\nintelligible, and does not necessarily belong to our problem, which\nmust be decided from mere concepts, independently of the properties\nwhich we meet in the actual world.\n\nNow I may say without contradiction: that all the actions of rational\nbeings, so far as they are appearances (occurring in any experience),\nare subject to the necessity of nature; but the same actions, as\nregards merely the rational subject and its faculty of acting\naccording to mere reason, are free. For what is required for the\nnecessity of nature? Nothing more than the determinability of every\nevent in the world of sense according to constant laws, that is, a\nreference to cause in the appearance; in this process the thing in\nitself at its foundation and its causality remain unknown. But I say,\nthat the law of nature remains, whether the rational being is the\ncause of the effects in the sensuous world from reason, that is,\nthrough freedom, or whether it does not determine them on grounds of\nreason. For, if the former is the case, the action is performed\naccording to maxims, the effect of which as appearance is always\nconform able to constant laws; if the latter is the case, and the\naction not performed on principles of reason, it is subjected to the\nempirical laws of the sensibility, and in both cases the effects are\nconnected according to constant laws; more than this we do not require\nor know concerning natural necessity. But in the former case reason is\nthe cause of these laws of nature, and therefore free; in the latter\nthe effects follow according to mere natural laws of sensibility,\nbecause reason does not influence it; but reason itself is not\ndetermined on that account by the sensibility, and is therefore free\nin this case too. Freedom is therefore no hindrance to natural law in\nappearance, neither does this law abrogate the freedom of the\npractical use of reason, which is connected with things in themselves,\nas determining grounds.\n\nThus practical freedom, viz., the freedom in which reason possesses\ncausality according to objectively determining grounds, is rescued and\nyet natural necessity is not in the least curtailed with regard to the\nvery same effects, as appearances. The same remarks will serve to\nexplain what we had to say concerning transcendental freedom and its\ncompatibility with natural necessity (in the same subject, but not\ntaken in the same reference). For, as to this, every beginning of the\naction of a being from objective causes regarded as determining\ngrounds, is always a first start, though the same action is in the\nseries of appearances only a subordinate start, which must be preceded\nby a state of the cause, which determines it, and is itself determined\nin the same manner by another immediately preceding. Thus we are able,\nin rational beings, or in beings generally, so far as their causality\nis determined in them as things in themselves, to imagine a faculty of\nbeginning from itself a series of states, without falling into\ncontradiction with the laws of nature. For the relation of the action\nto objective grounds of reason is not a time-relation; in this case\nthat which determines the causality does not precede in time the\naction, because such determining grounds represent not a reference to\nobjects of sense, e.g., to causes in the appearances, but to\ndetermining causes, as things in themselves, which do not rank under\nconditions of time. And in this way the action, with regard to the\ncausality of reason, can be considered as a first start in respect to\nthe series of appearances, and yet also as a merely subordinate\nbeginning. We may therefore without contradiction consider it in the\nformer aspect as free, but in the latter (in so far as it is merely\nappearance) as subject to natural necessity.\n\nAs to the fourth Antinomy, it is solved in the same way as the\nconflict of reason with itself in the third. For, provided the cause\nin the appearance is distinguished from the cause of the appearance\n(so far as it can be thought as a thing in itself), both propositions\nare perfectly reconcilable: the one, that there is nowhere in the\nsensuous world a cause (according to similar laws of causality), whose\nexistence is absolutely necessary; the other, that this world is\nnevertheless connected with a Necessary Being as its cause (but of\nanother kind and according to another law). The incompatibility of\nthese propositions entirely rests upon the mistake of extending what\nis valid merely of appearances to things in themselves, and in general\nconfusing both in one concept.\n\n\u00a7 54. This then is the proposition and this the solution of the whole\nantinomy, in which reason finds itself involved in the application of\nits principles to the sensible world. The former alone (the mere\nproposition) would be a considerable service in the cause of our\nknowledge of human reason, even though the solution might fail to\nfully satisfy the reader, who has here to combat a natural illusion,\nwhich has been but recently exposed to him, and which he had hitherto\nalways regarded as genuine. For one result at least is unavoidable. As\nit is quite impossible to prevent this conflict of reason with\nitself\u2014so long as the objects of the sensible world are taken for\nthings in themselves, and not for mere appearances, which they are in\nfact\u2014the reader is thereby compelled to examine over again the\ndeduction of all our a priori cognition and the proof which I have\ngiven of my deduction in order to come to a decision on the question.\nThis is all I require at present; for when in this occupation he shall\nhave thought himself deep enough into the nature of pure reason, those\nconcepts by which alone the solution of the conflict of reason is\npossible, will become sufficiently familiar to him. Without this\npreparation I cannot expect an unreserved assent even from the most\nattentive reader.\n\nIII. The Theological Idea.{37}\n\n===================================\n{37} Cf. Critique, the chapter on \"Transcendental Ideals.\"\n===================================\n\n\u00a7 55. The third transcendental Idea, which affords matter for the\nmost important, but, if pursued only speculatively, transcendent and\nthereby dialectical use of reason, is the ideal of pure reason. Reason\nin this case does not, as with the psychological and the cosmological\nIdeas, begin from experience, and err by exaggerating its grounds, in\nstriving to attain, if possible, the absolute completeness of their\nseries. It rather totally breaks with experience, and from mere\nconcepts of what constitutes the absolute completeness of a thing in\ngeneral, consequently by means of the idea of a most perfect primal\nBeing, it proceeds to determine the possibility and therefore the\nactuality of all other things. And so the mere presupposition of a\nBeing, who is conceived not in the series of experience, yet for the\npurposes of experience\u2014for the sake of comprehending its connexion,\norder, and unity\u2014i.e., the idea [the notion of it], is more easily\ndistinguished from the concept of the understanding here, than in the\nformer cases. Hence we can easily expose the dialectical illusion\nwhich arises from our making the subjective conditions of our thinking\nobjective conditions of objects themselves, and an hypothesis\nnecessary for the satisfaction of our reason, a dogma. As the\nobservations of the Critique on the pretensions of transcendental\ntheology are intelligible, clear, and decisive, I have nothing more to\nadd on the subject.\n\nGeneral Remark on the Transcendental Ideas.\n\n\u00a7 56. The objects, which are given us by experience, are in many\nrespects incomprehensible, and many questions, to which the law of\nnature leads us, when carried beyond a certain point (though quite\nconformably to the laws of nature), admit of no answer; as for example\nthe question: why substances attract one another? But if we entirely\nquit nature, or in pursuing its combinations, exceed all possible\nexperience, and so enter the realm of mere ideas, we cannot then say\nthat the object is incomprehensible, and that the nature of things\nproposes to us insoluble problems. For we are not then concerned with\nnature or in general with given objects, but with concepts, which have\ntheir origin merely in our reason, and with mere creations of thought;\nand all the problems that arise from our notions of them must be\nsolved, because of course reason can and must give a full account of\nits own procedure.{38} As the psychological, cosmological, and\ntheological Ideas are nothing but pure concepts of reason, which\ncannot be given in any experience, the questions which reason asks us\nabout them are put to us not by the objects, but by mere maxims of our\nreason for the sake of its own satisfaction. They must all be capable\nof satisfactory answers, which is done by showing that they are\nprinciples which bring our use of the understanding into thorough\nagreement, completeness, and synthetical unity, and that they so far\nhold good of experience only, but of experience as a whole.\n\n===================================\n{38} Herr Platner in his Aphorisms acutely says (\u00a7\u00a7 728, 729), \"If\nreason be a criterion, no concept, which is incomprehensible to human\nreason, can be possible. Incomprehensibility has place in what is\nactual only. Here in comprehensibility arises from the insufficiency\nof the acquired ideas.\" It sounds paradoxical, but is otherwise not\nstrange to say, that in nature there is much incomprehensible (e.g.,\nthe faculty of generation) but if we mount still higher, and even go\nbeyond nature, everything again becomes comprehensible; for we then\nquit entirely the objects, which can be given us, and occupy ourselves\nmerely about ideas, in which occupation we can easily comprehend the\nlaw that reason prescribes by them to the understanding for its use in\nexperience, because the law is the reason's own production.\n===================================\n\nAlthough an absolute whole of experience is impossible, the idea of a\nwhole of cognition according to principles must impart to our\nknowledge a peculiar kind of unity, that of a system, without which it\nis nothing but piecework, and cannot be used for proving the existence\nof a highest purpose (which can only be the general system of all\npurposes), I do not here refer only to the practical, but also to the\nhighest purpose of the speculative use of reason.\n\nThe transcendental Ideas therefore express the peculiar application of\nreason as a principle of systematic unity in the use of the\nunderstanding. Yet if we assume this unity of the mode of cognition to\nbe attached to the object of cognition, if we regard that which is\nmerely regulative to be constitutive, and if we persuade ourselves\nthat we can by means of these Ideas enlarge our cognition\ntranscendently, or far beyond all possible experience, while it only\nserves to render experience within itself as nearly complete as\npossible, i.e., to limit its progress by nothing that cannot belong to\nexperience: we suffer from a mere misunderstanding in our estimate of\nthe proper application of our reason and of its principles, and from a\nDialectic, which both confuses the empirical use of reason, and also\nsets reason at variance with itself.\n\nConclusion.\n\nOn the Determination of the Bounds of Pure Reason.\n\n\u00a7 57. Having adduced the clearest arguments, it would be absurd for\nus to hope that we can know more of any object, than belongs to the\npossible experience of it, or lay claim to the least atom of knowledge\nabout anything not assumed to be an object of possible experience,\nwhich would determine it according to the constitution it has in\nitself. For how could we determine anything in this way, since time,\nspace, and the categories, and still more all the concepts formed by\nempirical experience or perception in the sensible world (Anschauung),\nhave and can have no other use, than to make experience possible. And\nif this condition is omitted from the pure concepts of the\nunderstanding, they do not determine any object, and have no meaning\nwhatever.\n\nBut it would be on the other hand a still greater absurdity if we\nconceded no things in themselves, or set up our experience for the\nonly possible mode of knowing things, our way of beholding\n(Anschauung) them in space and in time for the only possible way, and\nour discursive understanding for the archetype of every possible\nunderstanding; in fact if we wished to have the principles of the\npossibility of experience considered universal conditions of things in\nthemselves.\n\nOur principles, which limit the use of reason to possible experience,\nmight in this way become transcendent, and the limits of our reason be\nset up as limits of the possibility of things in themselves (as Hume's\ndialogues may illustrate), if a careful critique did not guard the\nbounds of our reason with respect to its empirical use, and set a\nlimit to its pretensions. Scepticism originally arose from metaphysics\nand its licentious dialectics. At first it might, merely to favor the\nempirical use of reason, announce everything that transcends this use\nas worthless and deceitful; but by and by, when it was perceived that\nthe very same principles that are used in experience, insensibly, and\napparently with the same right, led still further than experience\nextends, then men began to doubt even the propositions of experience.\nBut here there is no danger; for common sense will doubtless always\nassert its rights. A certain confusion, however, arose in science\nwhich cannot determine how far reason is to be trusted, and why only\nso far and no further, and this confusion can only be cleared up and\nall future relapses obviated by a formal determination, on principle,\nof the boundary of the use of our reason.\n\nWe cannot indeed, beyond all possible experience, form a definite\nnotion of what things in themselves may be. Yet we are not at liberty\nto abstain entirely from inquiring into them; for experience never\nsatisfies reason fully, but in answering questions, refers us further\nand further back, and leaves us dissatisfied with regard to their\ncomplete solution. This any one may gather from the Dialectics of pure\nreason, which therefore has its good subjective grounds. Having\nacquired, as regards the nature of our soul, a clear conception of the\nsubject, and having come to the conviction, that its manifestations\ncannot be explained materialistically, who can refrain from asking\nwhat the soul really is, and, if no concept of experience suffices for\nthe purpose, from accounting for it by a concept of reason (that of a\nsimple immaterial being), though we cannot by any means prove its\nobjective reality? Who can satisfy himself with mere empirical\nknowledge in all the cosmological questions of the duration and of the\nquantity of the world, of freedom or of natural necessity, since every\nanswer given on principles of experience begets a fresh question,\nwhich likewise requires its answer and thereby clearly shows the\ninsufficiency of all physical modes of explanation to satisfy reason?\nFinally, who does not see in the thorough-going contingency and\ndependence of all his thoughts and assumptions on mere principles of\nexperience, the impossibility of stopping there? And who does not feel\nhimself compelled, notwithstanding all interdictions against losing\nhimself in transcendent ideas, to seek rest and contentment beyond all\nthe concepts which he can vindicate by experience, in the concept of a\nBeing, the possibility of which we cannot conceive, but at the same\ntime cannot be refuted, because it relates to a mere being of the\nunderstanding, and without it reason must needs remain forever\ndissatisfied?\n\nBounds (in extended beings) always presuppose a space existing outside\na certain definite place, and in closing it; limits do not require\nthis, but are mere negations, which affect a quantity, so far as it is\nnot absolutely complete. But our reason, as it were, sees in its\nsurroundings a space for the cognition of things in themselves, though\nwe can never have definite notions of them, and are limited to\nappearances only.\n\nAs long as the cognition of reason is homogeneous, definite bounds to\nit are inconceivable. In mathematics and in natural philosophy human\nreason admits of limits, but not of bounds, viz., that something\nindeed lies without it, at which it can never arrive, but not that it\nwill at any point find completion in its internal progress. The\nenlarging of our views in mathematics, and the possibility of new\ndiscoveries, are infinite; and the same is the case with the discovery\nof new properties of nature, of new powers and laws, by continued\nexperience and its rational combination. But limits cannot be mistaken\nhere, for mathematics refers to appearances only, and what cannot be\nan object of sensuous contemplation, such as the concepts of\nmetaphysics and of morals, lies entirely without its sphere, and it\ncan never lead to them; neither does it require them. It is therefore\nnot a continual progress and an approximation towards these sciences,\nand there is not, as it were, any point or line of contact. Natural\nscience will never reveal to us the internal constitution of things,\nwhich though not appearance, yet can serve as the ultimate ground of\nexplaining appearance. Nor does that science require this for its\nphysical explanations. Nay even if such grounds should be offered from\nother sources (for instance, the influence of immaterial beings), they\nmust be rejected and not used in the progress of its explanations. For\nthese explanations must only be grounded upon that which as an object\nof sense can belong to experience, and be brought into connexion with\nour actual perceptions and empirical laws.\n\nBut metaphysics leads us towards bounds in the dialectical attempts of\npure reason (not undertaken arbitrarily or wantonly, but stimulated\nthereto by the nature of reason itself). And the transcendental Ideas,\nas they do not admit of evasion, and are never capable of realisation,\nserve to point out to us actually not only the bounds of the pure use\nof reason, but also the way to determine them. Such is the end and the\nuse of this natural predisposition of our reason, which has brought\nforth metaphysics as its favorite child, whose generation, like every\nother in the world, is not to be ascribed to blind chance, but to an\noriginal germ, wisely organised for great ends. For metaphysics, in\nits fundamental features, perhaps more than any other science, is\nplaced in us by nature itself, and cannot be considered the production\nof an arbitrary choice or a casual enlargement in the progress of\nexperience from which it is quite disparate.\n\nReason with all its concepts and laws of the understanding, which\nsuffice for empirical use, i.e., within the sensible world, finds in\nitself no satisfaction because ever-recurring questions deprive us of\nall hope of their complete solution. The transcendental ideas, which\nhave that completion in view, are such problems of reason. But it sees\nclearly, that the sensuous world cannot contain this completion,\nneither consequently can all the concepts, which serve merely for\nunderstanding the world of sense, such as space and time, and whatever\nwe have adduced under the name of pure concepts of the understanding.\nThe sensuous world is nothing but a chain of appearances connected\naccording to universal laws; it has therefore no subsistence by\nitself; it is not the thing in itself, and consequently must point to\nthat which contains the basis of this experience, to beings which\ncannot be cognised merely as phenomena, but as things in themselves.\nIn the cognition of them alone reason can hope to satisfy its desire\nof completeness in proceeding from the conditioned to its conditions.\n\nWe have above (\u00a7\u00a7 33, 34) indicated the limits of reason with regard\nto all cognition of mere creations of thought. Now, since the\ntranscendental ideas have urged us to approach them, and thus have led\nus, as it were, to the spot where the occupied space (viz.,\nexperience) touches the void (that of which we can know nothing, viz.,\nnoumena), we can determine the bounds of pure reason. For in all\nbounds there is something positive (e.g., a surface is the boundary of\ncorporeal space, and is therefore itself a space, a line is a space,\nwhich is the boundary of the surface, a point the boundary of the\nline, but yet always a place in space), whereas limits contain mere\nnegations. The limits pointed out in those paragraphs are not enough\nafter we have discovered that beyond them there still lies something\n(though we can never cognise what it is in itself). For the question\nnow is, What is the attitude of our reason in this connexion of what\nwe know with what we do not, and never shall, know? This is an actual\nconnexion of a known thing with one quite unknown (and which will\nalways remain so), and though what is unknown should not become the\nleast more known\u2014which we cannot even hope\u2014yet the notion of this\nconnexion must be definite, and capable of being rendered distinct.\n\nWe must therefore accept an immaterial being, a world of\nunderstanding, and a Supreme Being (all mere noumena), because in them\nonly, as things in themselves, reason finds that completion and\nsatisfaction, which it can never hope for in the derivation of\nappearances from their homogeneous grounds, and because these actually\nhave reference to something distinct from them (and totally\nheterogeneous), as appearances always presuppose an object in itself,\nand therefore suggest its existence whether we can know more of it or\nnot.\n\nBut as we can never cognise these beings of understanding as they are\nin themselves, that is, definitely, yet must assume them as regards\nthe sensible world, and connect them with it by reason, we are at\nleast able to think this connexion by means of such concepts as\nexpress their relation to the world of sense. Yet if we represent to\nourselves a being of the understanding by nothing but pure concepts of\nthe understanding, we then indeed represent nothing definite to\nourselves, consequently our concept has no significance; but if we\nthink it by properties borrowed from the sensuous world, it is no\nlonger a being of understanding, but is conceived as an appearance,\nand belongs to the sensible world. Let us take an instance from the\nnotion of the Supreme Being.\n\nOur deistic conception is quite a pure concept of reason, but\nrepresents only a thing containing all realities, without being able\nto determine any one of them; because for that purpose an example must\nbe taken from the world of sense, in which case we should have an\nobject of sense only, not something quite heterogeneous, which can\nnever be an object of sense. Suppose I attribute to the Supreme Being\nunderstanding, for instance; I have no concept of an understanding\nother than my own, one that must receive its perceptions (Anschauung)\nby the senses, and which is occupied in bringing them under rules of\nthe unity of consciousness. Then the elements of my concept would\nalways lie in the appearance; I should however by the insufficiency of\nthe appearance be necessitated to go beyond them to the concept of a\nbeing which neither depends upon appearance, nor is bound up with them\nas conditions of its determination. But if I separate understanding\nfrom sensibility to obtain a pure understanding, then nothing remains\nbut the mere form of thinking without perception (Anschauung), by\nwhich form alone I can cognise nothing definite, and consequently no\nobject. For that purpose I should conceive another understanding, such\nas would directly perceive its objects,{39} but of which I have not the\nleast notion; because the human understanding is discursive, and can\n[not directly perceive, it can] only cognise by means of general\nconcepts. And the very same difficulties arise if we attribute a will\nto the Supreme Being; for we have this concept only by drawing it from\nour internal experience, and therefore from our dependence for\nsatisfaction upon objects whose existence we require; and so the\nnotion rests upon sensibility, which is absolutely incompatible with\nthe pure concept of the Supreme Being.\n\n===================================\n{39} Der die Gegenst\u00e4nde anschaute.\n===================================\n\nHume's objections to deism are weak, and affect only the proofs, and\nnot the deistic assertion itself. But as regards theism, which depends\non a stricter determination of the concept of the Supreme Being which\nin deism is merely transcendent, they are very strong, and as this\nconcept is formed, in certain (in fact in all common) cases\nirrefutable. Hume always insists, that by the mere concept of an\noriginal being, to which we apply only ontological predicates\n(eternity, omnipresence, omnipotence), we think nothing definite, and\nthat properties which can yield a concept in concreto must be\nsuperadded; that it is not enough to say, it is Cause, but we must\nexplain the nature of its causality, for example, that of an\nunderstanding and of a will. He then begins his attacks on the\nessential point itself, i.e., theism, as he had previously directed\nhis battery only against the proofs of deism, an attack which is not\nvery dangerous to it in its consequences. All his dangerous arguments\nrefer to anthropomorphism, which he holds to be inseparable from\ntheism, and to make it absurd in itself; but if the former be\nabandoned, the latter must vanish with it, and nothing remain but\ndeism, of which nothing can come, which is of no value, and which\ncannot serve as any foundation to religion or morals. If this\nanthropomorphism were really unavoidable, no proofs whatever of the\nexistence of a Supreme Being, even were they all granted, could\ndetermine for us the concept of this Being without involving us in\ncontradictions.\n\nIf we connect with the command to avoid all transcendent judgments of\npure reason, the command (which apparently conflicts with it) to\nproceed to concepts that lie beyond the field of its immanent\n(empirical) use, we discover that both can subsist together, but only\nat the boundary of all lawful use of reason. For this boundary belongs\nas well to the field of experience, as to that of the creations of\nthought, and we are thereby taught, as well, how these so remarkable\nideas serve merely for marking the bounds of human reason. On the one\nhand they give warning not boundlessly to extend cognition of\nexperience, as if nothing but world{40} remained for us to cognise, and\nyet, on the other hand, not to transgress the bounds of experience,\nand to think of judging about things beyond them, as things in\nthemselves.\n\n===================================\n{40} The use of the word \"world\" without article, though odd, seems to\nbe the correct reading, but it may be a mere misprint.\u2014 Ed.\n===================================\n\nBut we stop at this boundary if we limit our judgment merely to the\nrelation which the world may have to a Being whose very concept lies\nbeyond all the knowledge which we can attain within the world. For we\nthen do not attribute to the Supreme Being any of the properties in\nthemselves, by which we represent objects of experience, and thereby\navoid dogmatic anthropomorphism; but we attribute them to his relation\nto the world, and allow ourselves a symbolical anthropomorphism, which\nin fact concerns language only, and not the object itself.\n\nIf I say that we are compelled to consider the world, as if it were\nthe work of a Supreme Understanding and Will, I really say nothing\nmore, than that a watch, a ship, a regiment, bears the same relation\nto the watchmaker, the shipbuilder, the commanding officer, as the\nworld of sense (or whatever constitutes the substratum of this complex\nof appearances) does to the Unknown, which I do not hereby cognise as\nit is in itself, but as it is for me or in relation to the world, of\nwhich I am a part.\n\n\u00a7 58. Such a cognition is one of analogy, and does not signify (as is\ncommonly understood) an imperfect similarity of two things, but a\nperfect similarity of relations between two quite dissimilar things.{41}\nBy means of this analogy, however, there remains a concept of the\nSupreme Being sufficiently determined for us, though we have left out\neverything that could deter mine it absolutely or in itself; for we\ndetermine it as regards the world and as regards ourselves, and more\ndo we not require. The attacks which Hume makes upon those who would\ndetermine this concept absolutely, by taking the materials for so\ndoing from themselves and the world, do not affect us; and he cannot\nobject to us, that we have nothing left if we give up the objective\nanthropomorphism of the concept of the Supreme Being.\n\n===================================\n{41} There is, e.g., an analogy between the juridical relation of human\nactions and the mechanical relation of motive powers. I never can do\nanything to another man without giving him a right to do the same to\nme on the same conditions; just as no mass can act with its motive\npower on another mass without thereby occasioning the other to react\nequally against it. Here right and motive power are quite dissimilar\nthings, but in their relation there is complete similarity. By means\nof such an analogy I can obtain a notion of the relation of things\nwhich absolutely are unknown to me. For instance, as the promotion of\nthe welfare of children (= a) is to the love of parents (= b), so the\nwelfare of the human species (= c) is to that unknown [quantity which\nis] in God (= x), which we call love; not as if it had the least\nsimilarity to any human inclination, but because we can suppose its\nrelation to the world to be similar to that which things of the world\nbear one another. But the concept of relation in this case is a mere\ncategory, viz., the concept of cause, which has nothing to do with\nsensibility.\n===================================\n\nFor let us assume at the outset (as Hume in his dialogues makes Philo\ngrant Cleanthes), as a necessary hypothesis, the deistical concept of\nthe First Being, in which this Being is thought by the mere\nontological predicates of substance, of cause, etc. This must be done,\nbecause reason, actuated in the sensible world by mere conditions,\nwhich are themselves always conditional, cannot otherwise have any\nsatisfaction, and it therefore can be done without falling into\nanthropomorphism (which transfers predicates from the world of sense\nto a Being quite distinct from the world), because those predicates\nare mere categories, which, though they do not give a determinate\nconcept of God, yet give a concept not limited to any conditions of\nsensibility. Thus nothing can prevent our predicating of this Being a\ncausality through reason with regard to the world, and thus passing to\ntheism, without being obliged to attribute to God in himself this kind\nof reason, as a property inhering in him. For as to the former, the\nonly possible way of prosecuting the use of reason (as regards all\npossible experience, in complete harmony with itself) in the world of\nsense to the highest point, is to assume a supreme reason as a cause\nof all the connexions in the world. Such a principle must be quite\nadvantageous to reason and can hurt it nowhere in its application to\nnature. As to the latter, reason is thereby not transferred as a\nproperty to the First Being in himself, but only to his relation to\nthe world of sense, and so anthropomorphism is entirely avoided. For\nnothing is considered here but the cause of the form of reason which\nis perceived everywhere in the world, and reason is attributed to the\nSupreme Being, so far as it contains the ground of this form of reason\nin the world, but according to analogy only, that is, so far as this\nexpression shows merely the relation, which the Supreme Cause unknown\nto us has to the world, in order to determine everything in it\nconformably to reason in the highest degree. We are thereby kept from\nusing reason as an attribute for the purpose of conceiving God, but\ninstead of conceiving the world in such a manner as is necessary to\nhave the greatest possible use of reason according to principle. We\nthereby acknowledge that the Supreme Being is quite inscrutable and\neven unthinkable in any definite way as to what he is in himself. We\nare thereby kept, on the one hand, from making a transcendent use of\nthe concepts which we have of reason as an efficient cause (by means\nof the will), in order to determine the Divine Nature by properties,\nwhich are only borrowed from human nature, and from losing ourselves\nin gross and extravagant notions, and on the other hand from deluging\nthe contemplation of the world with hyperphysical modes of explanation\naccording to our notions of human reason, which we transfer to God,\nand so losing for this contemplation its proper application, according\nto which it should be a rational study of mere nature, and not a\npresumptuous derivation of its appearances from a Supreme Reason. The\nexpression suited to our feeble notions is, that we conceive the world\nas if it came, as to its existence and internal plan, from a Supreme\nReason, by which notion we both cognise the constitution, which\nbelongs to the world itself, yet without pretending to determine the\nnature of its cause in itself, and on the other hand, we transfer the\nground of this constitution (of the form of reason in the world) upon\nthe relation of the Supreme Cause to the world, without finding the\nworld sufficient by itself for that purpose.{42}\n\n===================================\n{42} I may say, that the causality of the Supreme Cause holds the same\nplace with regard to the world that human reason does with regard to\nits works of art. Here the nature of the Supreme Cause itself remains\nunknown to me: I only compare its effects (the order of the world)\nwhich I know, and their conformity to reason, to the effects of human\nreason which I also know; and hence I term the former reason, without\nattributing to it on that account what I understand in man by this\nterm, or attaching to it anything else known to me, as its property.\n===================================\n\nThus the difficulties which seem to oppose theism disappear by\ncombining with Hume's principle\u2014\"not to carry the use of reason\ndogmatically beyond the field of all possible experience\"\u2014this other\nprinciple, which he quite overlooked: \"not to consider the field of\nexperience as one which bounds itself in the eye of our reason.\" The\nCritique of Pure Reason here points out the true mean between\ndogmatism, which Hume combats, and skepticism, which he would\nsubstitute for it\u2014a mean which is not like other means that we find\nadvisable to determine for ourselves as it were mechanically (by\nadopting something from one side and something from the other), and by\nwhich nobody is taught a better way, but such a one as can be\naccurately determined on principles.\n\n\u00a7 59. At the beginning of this annotation I made use of the metaphor\nof a boundary, in order to establish the limits of reason in regard to\nits suitable use. The world of sense contains merely appearances,\nwhich are not things in themselves, but the understanding must assume\nthese latter ones, viz., noumena. In our reason both are comprised,\nand the question is, How does reason proceed to set boundaries to the\nunderstanding as regards both these fields? Experience, which contains\nall that belongs to the sensuous world, does not bound itself; it only\nproceeds in every case from the conditioned to some other equally\nconditioned object. Its boundary must lie quite without it, and this\nfield is that of the pure beings of the understanding. But this field,\nso far as the determination of the nature of these beings is\nconcerned, is an empty space for us, and if dogmatically-determined\nconcepts alone are in question, we cannot pass out of the field of\npossible experience. But as a boundary itself is something positive,\nwhich belongs as well to that which lies within, as to the space that\nlies without the given complex, it is still an actual positive\ncognition, which reason only acquires by enlarging itself to this\nboundary, yet without attempting to pass it; because it there finds\nitself in the presence of an empty space, in which it can conceive\nforms of things, but not things themselves. But the setting of a\nboundary to the field of the understanding by something, which is\notherwise unknown to it, is still a cognition which belongs to reason\neven at this standpoint, and by which it is neither confined within\nthe sensible, nor straying without it, but only refers, as befits the\nknowledge of a boundary, to the relation between that which lies\nwithout it, and that which is contained within it.\n\nNatural theology is such a concept at the boundary of human reason,\nbeing constrained to look beyond this boundary to the Idea of a\nSupreme Being (and, for practical purposes to that of an intelligible\nworld also), not in order to determine anything relatively to this\npure creation of the understanding, which lies beyond the world of\nsense, but in order to guide the use of reason within it according to\nprinciples of the greatest possible (theoretical as well as practical)\nunity. For this purpose we make use of the reference of the world of\nsense to an independent reason, as the cause of all its connexions.\nThereby we do not purely invent a being, but, as beyond the sensible\nworld there must be something that can only be thought by the pure\nunderstanding, we determine that something in this particular way,\nthough only of course according to analogy.\n\nAnd thus there remains our original proposition, which is the r\u00e9sum\u00e9\nof the whole Critique: \"that reason by all its a priori principles\nnever teaches us anything more than objects of possible experience,\nand even of these nothing more than can be cognised in experience.\"\nBut this limitation does not prevent reason leading us to the\nobjective boundary of experience, viz., to the reference to something\nwhich is not itself an object of experience, but is the ground of all\nexperience. Reason does not however teach us anything concerning the\nthing in itself: it only instructs us as regards its own complete and\nhighest use in the field of possible experience. But this is all that\ncan be reasonably desired in the present case, and with which we have\ncause to be satisfied.\n\n\u00a7 60. Thus we have fully exhibited metaphysics as it is actually\ngiven in the natural predisposition of human reason, and in that which\nconstitutes the essential end of its pursuit, according to its\nsubjective possibility. Though we have found, that this merely natural\nuse of such a predisposition of our reason, if no discipline arising\nonly from a scientific critique bridles and sets limits to it,\ninvolves us in transcendent, either apparently or really conflicting,\ndialectical syllogisms; and this fallacious metaphysics is not only\nunnecessary as regards the promotion of our knowledge of nature, but\neven disadvantageous to it: there yet remains a problem worthy of\nsolution, which is to find out the natural ends intended by this\ndisposition to transcendent concepts in our reason, because everything\nthat lies in nature must be originally intended for some useful\npurpose.\n\nSuch an inquiry is of a doubtful nature; and I acknowledge, that what\nI can say about it is conjecture only, like every speculation about\nthe first ends of nature. The question does not concern the objective\nvalidity of metaphysical judgments, but our natural predisposition to\nthem, and therefore does not belong to the system of metaphysics but\nto anthropology.\n\nWhen I compare all the transcendental Ideas, the totality of which\nconstitutes the particular problem of natural pure reason, compelling\nit to quit the mere contemplation of nature, to transcend all possible\nexperience, and in this endeavor to produce the thing (be it knowledge\nor fiction) called metaphysics, I think I perceive that the aim of\nthis natural tendency is, to free our notions from the fetters of\nexperience and from the limits of the mere contemplation of nature so\nfar as at least to open to us a field containing mere objects for the\npure understanding, which no sensibility can reach, not indeed for the\npurpose of speculatively occupying ourselves with them (for there we\ncan find no ground to stand on), but because practical principles,\nwhich, without finding some such scope for their necessary expectation\nand hope, could not expand to the universality which reason\nunavoidably requires from a moral point of view.\n\nSo I find that the Psychological Idea (however little it may reveal to\nme the nature of the human soul, which is higher than all concepts of\nexperience), shows the insufficiency of these concepts plainly enough,\nand thereby deters me from materialism, the psychological notion of\nwhich is unfit for any explanation of nature, and besides confines\nreason in practical respects. The Cosmological Ideas, by the obvious\ninsufficiency of all possible cognition of nature to satisfy reason in\nits lawful inquiry, serve in the same manner to keep us from\nnaturalism, which asserts nature to be sufficient for itself. Finally,\nall natural necessity in the sensible world is conditional, as it\nalways presupposes the dependence of things upon others, and\nunconditional necessity must be sought only in the unity of a cause\ndifferent from the world of sense. But as the causality of this cause,\nin its turn, were it merely nature, could never render the existence\nof the contingent (as its consequent) comprehensible, reason frees\nitself by means of the Theological Idea from fatalism, (both as a\nblind natural necessity in the coherence of nature itself, without a\nfirst principle, and as a blind causality of this principle itself),\nand leads to the concept of a cause possessing freedom, or of a\nSupreme Intelligence. Thus the transcendental Ideas serve, if not to\ninstruct us positively, at least to destroy the rash assertions of\nMaterialism, of Naturalism, and of Fatalism, and thus to afford scope\nfor the moral Ideas beyond the field of speculation. These\nconsiderations, I should think, explain in some measure the natural\npredisposition of which I spoke.\n\nThe practical value, which a merely speculative science may have, lies\nwithout the bounds of this science, and can therefore be considered as\na scholion merely, and like all scholia does not form part of the\nscience itself. This application however surely lies within the bounds\nof philosophy, especially of philosophy drawn from the pure sources of\nreason, where its speculative use in metaphysics must necessarily be\nat unity with its practical use in morals. Hence the unavoidable\ndialectics of pure reason, considered in metaphysics, as a natural\ntendency, deserves to be explained not as an illusion merely, which is\nto be removed, but also, if possible, as a natural provision as\nregards its end, though this duty, a work of supererogation, cannot\njustly be assigned to metaphysics proper.\n\nThe solutions of these questions which are treated in the chapter on\nthe Regulative Use of the Ideas of Pure Reason{43} should be considered\na second scholion which however has a greater affinity with the\nsubject of metaphysics. For there certain rational principles are\nexpounded which determine a priori the order of nature or rather of\nthe understanding, which seeks nature's laws through experience. They\nseem to be constitutive and legislative with regard to experience,\nthough they spring from pure reason, which cannot be considered, like\nthe understanding, as a principle of possible experience. Now whether\nor not this harmony rests upon the fact, that just as nature does not\ninhere in appearances or in their source (the sensibility) itself, but\nonly in so far as the latter is in relation to the understanding, as\nalso a systematic unity in applying the understanding to bring about\nan entirety of all possible experience can only belong to the\nunderstanding when in relation to reason; and whether or not\nexperience is in this way mediately subordinate to the legislation of\nreason: may be discussed by those who desire to trace the nature of\nreason even beyond its use in metaphysics, into the general principles\nof a history of nature; I have represented this task as important, but\nnot attempted its solution, in the book itself.{44}\n\n===================================\n{43} Critique of Pure Reason, II., chap. III., section 7.\n\n{44} Throughout in the Critique I never lost sight of the plan not to\nneglect anything, were it ever so recondite, that could render the\ninquiry into the nature of pure reason complete. Everybody may\nafterwards carry his researches as far as he pleases, when he has been\nmerely shown what yet remains to be done. It is this a duty which must\nreasonably be expected of him who has made it his business to survey\nthe whole field, in order to consign it to others for future\ncultivation and allotment. And to this branch both the scholia belong,\nwhich will hardly recommend themselves by their dryness to amateurs,\nand hence are added here for connoisseurs only.\n===================================\n\nAnd thus I conclude the analytical solution of the main question which\nI had proposed: How is metaphysics in general possible? by ascending\nfrom the data of its actual use in its consequences, to the grounds of\nits possibility.\n\nSCHOLIA.\n\nSOLUTION OF THE GENERAL QUESTION OF THE PROLEGOMENA, \"HOW IS\nMETAPHYSICS POSSIBLE AS A SCIENCE?\"\n\nMetaphysics, as a natural disposition of reason, is actual, but if\nconsidered by itself alone (as the analytical solution of the third\nprincipal question showed), dialectical and illusory. If we think of\ntaking principles from it, and in using them follow the natural, but\non that account not less false, illusion, we can never produce\nscience, but only a vain dialectical art, in which one school may\noutdo another, but none can ever acquire a just and lasting\napprobation.\n\nIn order that as a science metaphysics may be entitled to claim not\nmere fallacious plausibility, but in sight and conviction, a Critique\nof Reason must itself exhibit the whole stock of a priori concepts,\ntheir division according to their various sources (Sensibility,\nUnderstanding, and Reason), together with a complete table of them,\nthe analysis of all these concepts, with all their consequences,\nespecially by means of the deduction of these concepts, the\npossibility of synthetical cognition a priori, the principles of its\napplication and finally its bounds, all in a complete system.\nCritique, therefore, and critique alone, contains in itself the whole\nwell-proved and well-tested plan, and even all the means required to\naccomplish metaphysics, as a science; by other ways and means it is\nimpossible. The question here therefore is not so much how this\nperformance is possible, as how to set it going, and induce men of\nclear heads to quit their hitherto perverted and fruitless cultivation\nfor one that will not deceive, and how such a union for the common end\nmay best be directed.\n\nThis much is certain, that whoever has once tasted Critique will be\never after disgusted with all dogmatical twaddle which he formerly put\nup with, because his reason must have something, and could find\nnothing better for its support.\n\nCritique stands in the same relation to the common metaphysics of the\nschools, as chemistry does to alchemy, or as astronomy to the\nastrology of the fortune-teller. I pledge myself that nobody who has\nread through and through, and grasped the principles of, the Critique\neven in these Prolegomena only, will ever return to that old and\nsophistical pseudo-science; but will rather with a certain delight\nlook forward to metaphysics which is now indeed in his power,\nrequiring no more preparatory discoveries, and now at last affording\npermanent satisfaction to reason. For here is an advantage upon which,\nof all possible sciences, metaphysics alone can with certainty reckon:\nthat it can be brought to such completion and fixity as to be\nincapable of further change, or of any augmentation by new\ndiscoveries; because here reason has the sources of its knowledge in\nitself, not in objects and their observation (Anschauung), by which\nlatter its stock of knowledge cannot be further increased. When\ntherefore it has exhibited the fundamental laws of its faculty\ncompletely and so definitely as to avoid all misunderstanding, there\nremains nothing for pure reason to cognise a priori, nay, there is\neven no ground to raise further questions. The sure prospect of\nknowledge so definite and so compact has a peculiar charm, even though\nwe should set aside all its advantages, of which I shall hereafter\nspeak.\n\nAll false art, all vain wisdom, lasts its time, but finally destroys\nitself, and its highest culture is also the epoch of its decay. That\nthis time is come for metaphysics appears from the state into which it\nhas fallen among all learned nations, despite of all the zeal with\nwhich other sciences of every kind are prosecuted. The old arrangement\nof our university studies still preserves its shadow; now and then an\nAcademy of Science tempts men by offering prizes to write essays on\nit, but it is no longer numbered among thorough sciences; and let any\none judge for himself how a man of genius, if he were called a great\nmetaphysician, would receive the compliment, which may be well-meant,\nbut is scarce envied by anybody.\n\nYet, though the period of the downfall of all dogmatical metaphysics\nhas undoubtedly arrived, we are yet far from being able to say that\nthe period of its regeneration is come by means of a thorough and\ncomplete Critique of Reason. All transitions from a tendency to its\ncontrary pass through the stage of indifference, and this moment is\nthe most dangerous for an author, but, in my opinion, the most\nfavorable for the science. For, when party spirit has died out by a\ntotal dissolution of former connexions, minds are in the best state to\nlisten to several proposals for an organisation according to a new\nplan.\n\nWhen I say, that I hope these Prolegomena will excite investigation in\nthe field of critique and afford a new and promising object to sustain\nthe general spirit of philosophy, which seems on its speculative side\nto want sustenance, I can imagine beforehand, that every one, whom the\nthorny paths of my Critique have tired and put out of humor, will ask\nme, upon what I found this hope. My answer is, upon the irresistible\nlaw of necessity.\n\nThat the human mind will ever give up metaphysical researches is as\nlittle to be expected as that we should prefer to give up breathing\naltogether, to avoid inhaling impure air. There will therefore always\nbe metaphysics in the world; nay, every one, especially every man of\nreflexion, will have it, and for want of a recognised standard, will\nshape it for himself after his own pattern. What has hitherto been\ncalled metaphysics, cannot satisfy any critical mind, but to forego it\nentirely is impossible; therefore a Critique of Pure Reason itself\nmust now be attempted or, if one exists, investigated, and brought to\nthe full test, because there is no other means of supplying this\npressing want, which is something more than mere thirst for knowledge.\n\nEver since I have come to know critique, whenever I finish reading a\nbook of metaphysical contents, which, by the preciseness of its\nnotions, by variety, order, and an easy style, was not only\nentertaining but also helpful, I cannot help asking, \"Has this author\nindeed advanced metaphysics a single step?\" The learned men, whose\nworks have been useful to me in other respects and always contributed\nto the culture of my mental powers, will, I hope, forgive me for\nsaying, that I have never been able to find either their essays or my\nown less important ones (though self-love may recommend them to me) to\nhave advanced the science of metaphysics in the least, and why?\n\nHere is the very obvious reason: metaphysics did not then exist as a\nscience, nor can it be gathered piecemeal, but its germ must be fully\npreformed in the Critique. But in order to prevent all misconception,\nwe must remember what has been already said, that by the analytical\ntreatment of our concepts the understanding gains indeed a great deal,\nbut the science (of metaphysics) is thereby not in the least advanced,\nbecause these dissections of concepts are nothing but the materials\nfrom which the intention is to carpenter our science. Let the concepts\nof substance and of accident be ever so well dissected and determined,\nall this is very well as a preparation for some future use. But if we\ncannot prove, that in all which exists the substance endures, and only\nthe accidents vary, our science is not the least advanced by all our\nanalyses.\n\nMetaphysics has hitherto never been able to prove a priori either this\nproposition, or that of sufficient reason, still, less any more\ncomplex theorem, such as belongs to psychology or cosmology, or indeed\nany synthetical proposition. By all its analysing therefore nothing is\naffected, nothing obtained or forwarded, and the science, after all\nthis bustle and noise, still remains as it was in the days of\nAristotle, though far better preparations were made for it than of\nold, if the clue to synthetical cognitions had only been discovered.\n\nIf any one thinks himself offended, he is at liberty to refute my\ncharge by producing a single synthetical proposition belonging to\nmetaphysics, which he would prove dogmatically a priori, for until he\nhas actually performed this feat, I shall not grant that he has truly\nadvanced the science; even should this proposition be sufficiently\nconfirmed by common experience. No demand can be more moderate or more\nequitable, and in the (inevitably certain) event of its\nnon-performance, no assertion more just, than that hitherto\nmetaphysics has never existed as a science.\n\nBut there are two things which, in case the challenge be accepted, I\nmust deprecate: first, trifling about probability and conjecture,\nwhich are suited as little to metaphysics, as to geometry; and\nsecondly, a decision by means of the magic wand of common sense, which\ndoes not convince every one, but which accommodates itself to personal\npeculiarities.\n\nFor as to the former, nothing can be more absurd, than in metaphysics,\na philosophy from pure reason to think of grounding our judgments upon\nprobability and conjecture. Everything that is to be cognised a\npriori, is thereby announced as apodeictically certain, and must\ntherefore be proved in this way. We might as well think of grounding\ngeometry or arithmetic upon conjectures. As to the doctrine of chances\nin the latter, it does not contain probable, but perfectly certain,\njudgments concerning the degree of the probability of certain cases,\nunder given uniform conditions, which, in the sum of all possible\ncases, infallibly happen according to the rule, though it is not\nsufficiently determined in respect to every single chance. Conjectures\n(by means of induction and of analogy) can be suffered in an empirical\nscience of nature only, yet even there the possibility at least of\nwhat we assume must be quite certain.\n\nThe appeal to common sense is even more absurd, when concept and\nprinciples are announced as valid, not in so far as they hold with\nregard to experience, but even beyond the conditions of experience.\nFor what is common sense? It is normal good sense, so far it judges\nright. But what is normal good sense? It is the faculty of the\nknowledge and use of rules in concreto, as distinguished from the\nspeculative understanding, which is a faculty of knowing rules in\nabstracto. Common sense can hardly understand the rule, \"that every\nevent is determined by means of its cause,\" and can never comprehend\nit thus generally. It therefore demands an example from experience,\nand when it hears that this rule means nothing but what it always\nthought when a pane was broken or a kitchen-utensil missing, it then\nunderstands the principle and grants it. Common sense therefore is\nonly of use so far as it can see its rules (though they actually are a\npriori) confirmed by experience; consequently to comprehend them a\npriori, or independently of experience, belongs to the speculative\nunderstanding, and lies quite beyond the horizon of common sense. But\nthe province of metaphysics is entirely confined to the latter kind of\nknowledge, and it is certainly a bad index of common sense to appeal\nto it as a witness, for it cannot here form any opinion whatever, and\nmen look down upon it with contempt until they are in difficulties,\nand can find in their speculation neither in nor out.\n\nIt is a common subterfuge of those false friends of common sense (who\noccasionally prize it highly, but usually despise it) to say, that\nthere must surely be at all events some propositions which are\nimmediately certain, and of which there is no occasion to give any\nproof, or even any account at all, because we otherwise could never\nstop inquiring into the grounds of our judgments. But if we except the\nprinciple of contradiction, which is not sufficient to show the truth\nof synthetical judgments, they can never adduce, in proof of this\nprivilege, anything else indubitable, which they can immediately\nascribe to common sense, except mathematical propositions, such as\ntwice two make four, between two points there is but one straight\nline, etc. But these judgments are radically different from those of\nmetaphysics. For in mathematics I myself can by thinking construct\nwhatever I represent to myself as possible by a concept: I add to the\nfirst two the other two, one by one, and myself make the number four,\nor I draw in thought from one point to another all manner of lines,\nequal as well as unequal; yet I can draw one only, which is like\nitself in all its parts. But I cannot, by all my power of thinking,\nextract from the concept of a thing the concept of something else,\nwhose existence is necessarily connected with the former, but I must\ncall in experience. And though my understanding furnishes me a priori\n(yet only in reference to possible experience) with the concept of\nsuch a connexion (i.e., causation), I cannot exhibit it, like the\nconcepts of mathematics, by (Anschauung) visualising them, a priori,\nand so show its possibility a priori. This concept, together with the\nprinciples of its application, always requires, if it shall hold a\npriori\u2014as is requisite in metaphysics\u2014a justification and\ndeduction of its possibility, because we cannot otherwise know how far\nit holds good, and whether it can be used in experience only or beyond\nit also.\n\nTherefore in metaphysics, as a speculative science of pure reason, we\ncan never appeal to common sense, but may do so only when we are\nforced to surrender it, and to renounce all purely speculative\ncognition, which must always be knowledge, and consequently when we\nforego metaphysics itself and its instruction, for the sake of\nadopting a rational faith which alone may be possible for us, and\nsufficient to our wants, perhaps even more salutary than knowledge\nitself. For in this case the attitude of the question is quite\naltered. Metaphysics must be science, not only as a whole, but in all\nits parts, otherwise it is nothing; because, as a speculation of pure\nreason, it finds a hold only on general opinions. Beyond its field,\nhowever, probability and common sense may be used with advantage and\njustly, but on quite special principles, of which the importance\nalways depends on the reference to practical life.\n\nThis is what I hold myself justified in requiring for the possibility\nof metaphysics as a science.\n\nAPPENDIX.\n\nON WHAT CAN BE DONE TO MAKE METAPHYSICS ACTUAL AS A SCIENCE.\n\nSince all the ways heretofore taken have failed to attain the goal,\nand since without a preceding critique of pure reason it is not likely\never to be attained, the present essay now before the public has a\nfair title to an accurate and careful investigation, except it be\nthought more advisable to give up all pretensions to metaphysics, to\nwhich, if men but would consistently adhere to their purpose, no\nobjection can be made.\n\nIf we take the course of things as it is, not as it ought to be, there\nare two sorts of judgments: (1) one a judgment which precedes\ninvestigation (in our case one in which the reader from his own\nmetaphysics pronounces judgment on the Critique of Pure Reason which\nwas intended to discuss the very possibility of metaphysics); (2) the\nother a judgment subsequent to investigation. In the latter the reader\nis enabled to waive for awhile the consequences of the critical\nresearches that may be repugnant to his formerly adopted metaphysics,\nand first examines the grounds whence those consequences are derived.\nIf what common metaphysics propounds were demonstrably certain, as for\ninstance the theorems of geometry, the former way of judging would\nhold good. For if the consequences of certain principles are repugnant\nto established truths, these principles are false and without further\ninquiry to be repudiated. But if metaphysics does not possess a stock\nof indisputably certain (synthetical) propositions, and should it even\nbe the case that there are a number of them, which, though among the\nmost specious, are by their consequences in mutual collision, and if\nno sure criterion of the truth of peculiarly metaphysical\n(synthetical) propositions is to be met with in it, then the former\nway of judging is not admissible, but the investigation of the\nprinciples of the critique must precede all judgments as to its value.\n\nON A SPECIMEN OF A JUDGMENT OF THE CRITIQUE PRIOR TO ITS EXAMINATION.\n\nThis judgment is to be found in the G\u00f6ttingischen gelehrten Anzeigen,\nin the supplement to the third division, of January 19, 1782,\npages\u00a040 et seq.\n\nWhen an author who is familiar with the subject of his work and\nendeavors to present his independent reflexions in its elaboration,\nfalls into the hands of a reviewer who, in his turn, is keen enough to\ndiscern the points on which the worth or worthlessness of the book\nrests, who does not cling to words, but goes to the heart of the\nsubject, sifting and testing more than the mere principles which the\nauthor takes as his point of departure, the severity of the judgment\nmay indeed displease the latter, but the public does not care, as it\ngains thereby; and the author himself may be contented, as an\nopportunity of correcting or explaining his positions is afforded to\nhim at an early date by the examination of a competent judge, in such\na manner, that if he believes himself fundamentally right, he can\nremove in time any stone of offence that might hurt the success of his\nwork.\n\nI find myself, with my reviewer, in quite another position. He seems\nnot to see at all the real matter of the investigation with which\n(successfully or unsuccessfully) I have been occupied. It is either\nimpatience at thinking out a lengthy work, or vexation at a threatened\nreform of a science in which he believed he had brought everything to\nperfection long ago, or, what I am unwilling to imagine, real\nnarrowmindedness, that prevents him from ever carrying his thoughts\nbeyond his school-metaphysics. In short, he passes impatiently in\nreview a long series of propositions, by which, without knowing their\npremises, we can think nothing, intersperses here and there his\ncensure, the reason of which the reader understands just as little as\nthe propositions against which it is directed; and hence [his report]\ncan neither serve the public nor damage me, in the judgment of\nexperts. I should, for these reasons, have passed over this judgment\naltogether, were it not that it may afford me occasion for some\nexplanations which may in some cases save the readers of these\nProlegomena from a misconception.\n\nIn order to take a position from which my reviewer could most easily\nset the whole work in a most unfavorable light, without venturing to\ntrouble himself with any special investigation, he begins and ends by\nsaying:\n\n\"This work is a system of transcendent (or, as he translates it, of\nhigher) Idealism.\"{45}\n\n===================================\n{45} By no means \"higher.\" High towers, and metaphysically-great men\nresembling them, round both of which there is commonly much wind, are\nnot for me. My place is the fruitful bathos, the bottom-land, of\nexperience; and the word transcendental, the meaning of which is so\noften explained by me, but not once grasped by my reviewer (so\ncarelessly has he regarded everything), does not signify something\npassing beyond all experience, but something that indeed precedes it a\npriori, but that is intended simply to make cognition of experience\npossible. If these conceptions overstep experience, their employment\nis termed transcendent, a word which must be distinguished from\ntranscendental, the latter being limited to the immanent use, that is,\nto experience. All misunderstandings of this kind have been\nsufficiently guarded against in the work itself, but my reviewer found\nhis advantage in misunderstanding me.\n===================================\n\nA glance at this line soon showed me the sort of criticism that I had\nto expect, much as though the reviewer were one who had never seen or\nheard of geometry, having found a Euclid, and coming upon various\nfigures in turning over its leaves, were to say, on being asked his\nopinion of it: \"The work is a text-book of drawing; the author\nintroduces a peculiar terminology, in order to give dark,\nincomprehensible directions, which in the end teach nothing more than\nwhat every one can effect by a fair natural accuracy of eye, etc.\"\n\nLet us see, in the meantime, what sort of an idealism it is that goes\nthrough my whole work, although it does not by a long way constitute\nthe soul of the system.\n\nThe dictum of all genuine idealists from the Eleatic school to Bishop\nBerkeley, is contained in this formula: \"All cognition through the\nsenses and experience is nothing but sheer illusion, and only, in the\nideas of the pure understanding and reason there is truth.\"\n\nThe principle that throughout dominates and determines my Idealism, is\non the contrary: \"All cognition of things merely from pure\nunderstanding or pure reason is nothing but sheer illusion, and only\nin experience is there truth.\"\n\nBut this is directly contrary to idealism proper. How came I then to\nuse this expression for quite an opposite purpose, and how came my\nreviewer to see it everywhere?\n\nThe solution of this difficulty rests on something that could have\nbeen very easily understood from the general bearing of the work, if\nthe reader had only desired to do so. Space and time, together with\nall that they contain, are not things nor qualities in themselves, but\nbelong merely to the appearances of the latter: up to this point I am\none in confession with the above idealists. But these, and amongst\nthem more particularly Berkeley, regarded space as a mere empirical\npresentation that, like the phenomenon it contains, is only known to\nus by means of experience or perception, together with its\ndeterminations. I, on the contrary, prove in the first place, that\nspace (and also time, which Berkeley did not consider) and all its\ndeterminations a priori, can be cognised by us, because, no less than\ntime, it inheres in our sensibility as a pure form before all\nperception or experience and makes all intuition of the same, and\ntherefore all its phenomena, possible. It follows from this, that as\ntruth rests on universal and necessary laws as its criteria,\nexperience, according to Berkeley, can have no criteria of truth,\nbecause its phenomena (according to him) have nothing a priori at\ntheir foundation; whence it follows, that they are nothing but sheer\nillusion; whereas with us, space and time (in conjunction with the\npure conceptions of the understanding) prescribe their law to all\npossible experience a priori, and at the same time afford the certain\ncriterion for distinguishing truth from illusion therein.{46}\n\n===================================\n{46} Idealism proper always has a mystical tendency, and can have no\nother, but mine is solely designed for the purpose of comprehending\nthe possibility of our cognition a priori as to objects of experience,\nwhich is a problem never hitherto solved or even suggested. In this\nway all mystical idealism falls to the ground, for (as may be seen\nalready in Plato) it inferred from our cognitions a priori (even from\nthose of geometry) another intuition different from that of the senses\n(namely, an intellectual intuition), because it never occurred to any\none that the senses themselves might intuite a priori.\n===================================\n\nMy so-called (properly critical) Idealism is of quite a special\ncharacter, in that it subverts the ordinary idealism, and that through\nit all cognition a priori, even that of geometry, first receives\nobjective reality, which, without my demonstrated ideality of space\nand time, could not be maintained by the most zealous realists. This\nbeing the state of the case, I could have wished, in order to avoid\nall misunderstanding, to have named this conception of mine otherwise,\nbut to alter it altogether was impossible. It may be permitted me\nhowever, in future, as has been above intimated, to term it the\nformal, or better still, the critical Idealism, to distinguish it from\nthe dogmatic Idealism of Berkeley, and from the sceptical Idealism of\nDescartes.\n\nBeyond this, I find nothing further remarkable in the judgment of my\nbook. The reviewer criticises here and there, makes sweeping\ncriticisms, a mode prudently chosen, since it does not betray one's\nown knowledge or ignorance; a single thorough criticism in detail, had\nit touched the main question, as is only fair, would have exposed, it\nmay be my error, or it may be my reviewer's measure of insight into\nthis species of research. It was, moreover, not a badly conceived\nplan, in order at once to take from readers (who are accustomed to\nform their conceptions of books from newspaper reports) the desire to\nread the book itself, to pour out in one breath a number of passages\nin succession, torn from their connexion, and their grounds of proof\nand explanations, and which must necessarily sound senseless,\nespecially considering how antipathetic they are to all\nschool-metaphysics; to exhaust the reader's patience ad nauseam, and\nthen, after having made me acquainted with the sensible proposition\nthat persistent illusion is truth, to conclude with the crude paternal\nmoralisation: to what end, then, the quarrel with accepted language,\nto what end, and whence, the idealistic distinction? A judgment which\nseeks all that is characteristic of my book, first supposed to be\nmetaphysically heterodox, in a mere innovation of the nomenclature,\nproves clearly that my would-be judge has understood nothing of the\nsubject, and in addition, has not understood himself.{47}\n\n===================================\n{47} The reviewer often fights with his own shadow. When I oppose the\ntruth of experience to dream, he never thinks that I am here speaking\nsimply of the well-known somnio objective sumto of the Wolffian\nphilosophy, which is merely formal, and with which the distinction\nbetween sleeping and waking is in no way concerned, and in a\ntranscendental philosophy indeed can have no place. For the rest, he\ncalls my deduction of the categories and table of the principles of\nthe understanding, \"common well-known axioms of logic and ontology,\nexpressed in an idealistic manner.\" The reader need only consult these\nProlegomena upon this point, to convince himself that a more miserable\nand historically incorrect, judgment, could hardly be made.\n===================================\n\nMy reviewer speaks like a man who is conscious of important and\nsuperior insight which he keeps hidden; for I am aware of nothing\nrecent with respect to metaphysics that could justify his tone. But he\nshould not withhold his discoveries from the world, for there are\ndoubtless many who, like myself, have not been able to find in all the\nfine things that have for long past been written in this department,\nanything that has advanced the science by so much as a fingerbreadth;\nwe find indeed the giving a new point to definitions, the supplying of\nlame proofs with new crutches, the adding to the crazy-quilt of\nmetaphysics fresh patches or changing its pattern; but all this is not\nwhat the world requires. The world is tired of metaphysical\nassertions; it wants the possibility of the science, the sources from\nwhich certainty therein can be derived, and certain criteria by which\nit may distinguish the dialectical illusion of pure reason from truth.\nTo this the critic seems to possess a key, otherwise he would never\nhave spoken out in such a high tone.\n\nBut I am inclined to suspect that no such requirement of the science\nhas ever entered his thoughts, for in that case he would have directed\nhis judgment to this point, and even a mistaken attempt in such an\nimportant matter, would have won his respect. If that be the case, we\nare once more good friends. He may penetrate as deeply as he likes\ninto metaphysics, without any one hindering him; only as concerns that\nwhich lies outside metaphysics, its sources, which are to be found in\nreason, he cannot form a judgment. That my suspicion is not without\nfoundation, is proved by the fact that he does not mention a word\nabout the possibility of synthetic knowledge a priori, the special\nproblem upon the solution of which the fate of metaphysics wholly\nrests, and upon which my Critique (as well as the present Prolegomena)\nentirely hinges. The Idealism he encountered, and which he hung upon,\nwas only taken up in the doctrine as the sole means of solving the\nabove problem (although it received its confirmation on other\ngrounds), and hence he must have shown either that the above problem\ndoes not possess the importance I attribute to it (even in these\nProlegomena), or that by my conception of appearances, it is either\nnot solved at all, or can be better solved in another way; but I do\nnot find a word of this in the criticism. The reviewer, then,\nunderstands nothing of my work, and possibly also nothing of the\nspirit and essential nature of metaphysics itself; and it is not, what\nI would rather assume, the hurry of a man incensed at the labor of\nplodding through so many obstacles, that threw an unfavorable shadow\nover the work lying before him, and made its fundamental features\nunrecognisable.\n\nThere is a good deal to be done before a learned journal, it matters\nnot with what care its writers may be selected, can maintain its\notherwise well-merited reputation, in the field of metaphysics as\nelsewhere. Other sciences and branches of knowledge have their\nstandard. Mathematics has it, in itself; history and theology, in\nprofane or sacred books; natural science and the art of medicine, in\nmathematics and experience; jurisprudence, in law books; and even\nmatters of taste in the examples of the ancients. But for the judgment\nof the thing called metaphysics, the standard has yet to be found. I\nhave made an attempt to determine it, as well as its use. What is to\nbe done, then, until it be found, when works of this kind have to be\njudged of? If they are of a dogmatic character, one may do what one\nlikes; no one will play the master over others here for long, before\nsomeone else appears to deal with him in the same manner. If, however,\nthey are critical in their character, not indeed with reference to\nother works, but to reason itself, so that the standard of judgment\ncannot be assumed but has first of all to be sought for, then, though\nobjection and blame may indeed be permitted, yet a certain degree of\nleniency is indispensable, since the need is common to us all, and the\nlack of the necessary insight makes the high-handed attitude of judge\nunwarranted.\n\nIn order, however, to connect my defence with the interest of the\nphilosophical commonwealth, I propose a test, which must be decisive\nas to the mode, whereby all metaphysical investigations may be\ndirected to their common purpose. This is nothing more than what\nformerly mathematicians have done, in establishing the advantage of\ntheir methods by competition. I challenge my critic to demonstrate, as\nis only just, on a priori grounds, in his way, a single really\nmetaphysical principle asserted by him. Being metaphysical it must be\nsynthetic and cognised a priori from conceptions, but it may also be\nany one of the most indispensable principles, as for instance, the\nprinciple of the persistence of substance, or of the necessary\ndetermination of events in the world by their causes. If he cannot do\nthis (silence however is confession), he must admit, that as\nmetaphysics without apodeictic certainty of propositions of this kind\nis nothing at all, its possibility or impossibility must before all\nthings be established in a critique of the pure reason. Thus he is\nbound either to confess that my principles in the Critique are\ncorrect, or he must prove their invalidity. But as I can already\nforesee, that, confidently as he has hitherto relied on the certainty\nof his principles, when it comes to a strict test he will not find a\nsingle one in the whole range of metaphysics he can bring forward, I\nwill concede to him an advantageous condition, which can only be\nexpected in such a competition, and will relieve him of the onus\nprobandi by laying it on myself.\n\nHe finds in these Prolegomena and in my Critique (chapter on the\n\"Theses and Antitheses of the Four Antinomies\") eight propositions, of\nwhich two and two contradict one another, but each of which\nnecessarily belongs to metaphysics, by which it must either be\naccepted or rejected (although there is not one that has not in this\ntime been held by some philosopher). Now he has the liberty of\nselecting any one of these eight propositions at his pleasure, and\naccepting it without any proof, of which I shall make him a present,\nbut only one (for waste of time will be just as little serviceable to\nhim as to me), and then of attacking my proof of the opposite\nproposition. If I can save this one, and at the same time show, that\naccording to principles which every dogmatic metaphysics must\nnecessarily recognise, the opposite of the proposition adopted by him\ncan be just as clearly proved, it is thereby established that\nmetaphysics has an hereditary failing, not to be explained, much less\nset aside, until we ascend to its birth-place, pure reason itself, and\nthus my Critique must either be accepted or a better one take its\nplace; it must at least be studied, which is the only thing I now\nrequire. If, on the other hand, I cannot save my demonstration, then a\nsynthetic proposition a priori from dogmatic principles is to be\nreckoned to the score of my opponent, then also I will deem my\nimpeachment of ordinary metaphysics as unjust, and pledge myself to\nrecognise his stricture on my Critique as justified (although this\nwould not be the consequence by a long way). To this end it would be\nnecessary, it seems to me, that he should step out of his incognito.\nOtherwise I do not see how it could be avoided, that instead of\ndealing with one, I should be honored by several problems coming from\nanonymous and unqualified opponents.\n\nPROPOSALS AS TO AN INVESTIGATION OF THE CRITIQUE UPON WHICH A JUDGMENT\nMAY FOLLOW.\n\nI feel obliged to the honored public even for the silence with which\nit for a long time favored my Critique, for this proves at least a\npostponement of judgment, and some supposition that in a work, leaving\nall beaten tracks and striking out on a new path, in which one cannot\nat once perhaps so easily find one's way, something may perchance lie,\nfrom which an important but at present dead branch of human knowledge\nmay derive new life and productiveness. Hence may have originated a\nsolicitude for the as yet tender shoot, lest it be destroyed by a\nhasty judgment. A test of a judgment, delayed for the above reasons,\nis now before my eye in the Gothaischen gelehrten Zeitung, the\nthoroughness of which every reader will himself perceive, from the\nclear and unperverted presentation of a fragment of one of the first\nprinciples of my work, without taking into consideration my own\nsuspicious praise.\n\nAnd now I propose, since an extensive structure cannot be judged of as\na whole from a hurried glance, to test it piece by piece from its\nfoundations, so thereby the present Prolegomena may fitly be used as a\ngeneral outline with which the work itself may occasionally be\ncompared. This notion, if it were founded on nothing more than my\nconceit of importance, such as vanity commonly attributes to one's own\nproductions, would be immodest and would deserve to be repudiated with\ndisgust. But now, the interests of speculative philosophy have arrived\nat the point of total extinction, while human reason hangs upon them\nwith inextinguishable affection, and only after having been\nceaselessly deceived does it vainly attempt to change this into\nindifference.\n\nIn our thinking age it is not to be supposed but that many deserving\nmen would use any good opportunity of working for the common interest\nof the more and more enlightened reason, if there were only some hope\nof attaining the goal. Mathematics, natural science, laws, arts, even\nmorality, etc., do not completely fill the soul; there is always a\nspace left over, reserved for pure and speculative reason, the vacuity\nof which prompts us to seek in vagaries, buffooneries, and myticism\nfor what seems to be employment and entertainment, but what actually\nis mere pastime; in order to deaden the troublesome voice of reason,\nwhich in accordance with its nature requires something that can\nsatisfy it, and not merely subserve other ends or the interests of our\ninclinations. A consideration, therefore, which is concerned only with\nreason as it exists for it itself, has as I may reasonably suppose a\ngreat fascination for every one who has attempted thus to extend his\nconceptions, and I may even say a greater than any other theoretical\nbranch of knowledge, for which he would not willingly exchange it,\nbecause here all other cognitions, and even purposes, must meet and\nunite themselves in a whole.\n\nI offer, therefore, these Prolegomena as a sketch and text-book for\nthis investigation, and not the work itself. Although I am even now\nperfectly satisfied with the latter as far as contents, order, and\nmode of presentation, and the care that I have expended in weighing\nand testing every sentence before writing it down, are concerned (for\nit has taken me years to satisfy myself fully, not only as regards the\nwhole, but in some cases even as to the sources of one particular\nproposition); yet I am not quite satisfied with my exposition in some\nsections of the doctrine of elements, as for instance in the deduction\nof the conceptions of the Understanding, or in that on the paralogisms\nof pure reason, because a certain diffuseness takes away from their\nclearness, and in place of them, what is here said in the Prolegomena\nrespecting these sections, may be made the basis of the test.\n\nIt is the boast of the Germans that where steady and continuous\nindustry are requisite, they can carry things farther than other\nnations. If this opinion be well founded, an opportunity, a business,\npresents itself, the successful issue of which we can scarcely doubt,\nand in which all thinking men can equally take part, though they have\nhitherto been unsuccessful in accomplishing it and in thus confirming\nthe above good opinion. But this is chiefly because the science in\nquestion is of so peculiar a kind, that it can be at once brought to\ncompletion and to that enduring state that it will never be able to be\nbrought in the least degree farther or increased by later discoveries,\nor even changed (leaving here out of account adornment by greater\nclearness in some places, or additional uses), and this is an\nadvantage no other science has or can have, because there is none so\nfully isolated and independent of others, and which is concerned with\nthe faculty of cognition pure and simple. And the present moment\nseems, moreover, not to be unfavorable to my expectation, for just\nnow, in Germany, no one seems to know wherewith to occupy himself,\napart from the so-called useful sciences, so as to pursue not mere\nplay, but a business possessing an enduring purpose.\n\nTo discover the means how the endeavors of the learned may be united\nin such a purpose, I must leave to others. In the meantime, it is my\nintention to persuade any one merely to follow my propositions, or\neven to flatter me with the hope that he will do so; but attacks,\nrepetitions, limitations, or confirmation, completion, and extension,\nas the case may be, should be appended. If the matter be but\ninvestigated from its foundation, it cannot fail that a system, albeit\nnot my own, shall be erected, that shall be a possession for future\ngenerations for which they may have reason to be grateful.\n\nIt would lead us too far here to show what kind of metaphysics may be\nexpected, when only the principles of criticism have been perfected,\nand how, because the old false feathers have been pulled out, she need\nby no means appear poor and reduced to an insignificant figure, but\nmay be in other respects richly and respectably adorned. But other and\ngreat uses which would result from such a reform, strike one\nimmediately. The ordinary metaphysics had its uses, in that it sought\nout the elementary conceptions of the pure understanding in order to\nmake them clear through analysis, and definite by explanation. In this\nway it was a training for reason, in whatever direction it might be\nturned; but this was all the good it did; service was subsequently\neffaced when it favored conceit by venturesome assertions, sophistry\nby subtle distinctions and adornment, and shallowness by the ease with\nwhich it decided the most difficult problems by means of a little\nschool-wisdom, which is only the more seductive the more it has the\nchoice, on the one hand, of taking something from the language of\nscience, and on the other from that of popular discourse, thus being\neverything to everybody, but in reality nothing at all. By criticism,\nhowever, a standard is given to our judgment, whereby knowledge may be\nwith certainty distinguished from pseudo-science, and firmly founded,\nbeing brought into full operation in metaphysics; a mode of thought\nextending by degrees its beneficial influence over every other use of\nreason, at once infusing into it the true philosophical spirit. But\nthe service also that metaphysics performs for theology, by making it\nindependent of the judgment of dogmatic speculation, thereby assuring\nit completely against the attacks of all such opponents, is certainly\nnot to be valued lightly. For ordinary metaphysics, although it\npromised the latter much advantage, could not keep this promise, and\nmoreover, by summoning speculative dogmatics to its assistance, did\nnothing but arm enemies against itself. Mysticism, which can prosper\nin a rationalistic age only when it hides itself behind a system of\nschool-metaphysics, under the protection of which it may venture to\nrave with a semblance of rationality, is driven from this, its last\nhiding-place, by critical philosophy. Last, but not least, it cannot\nbe otherwise than important to a teacher of metaphysics, to be able to\nsay with universal assent, that what he expounds is Science, and that\nthereby genuine services will be rendered to the commonweal.","title":"Kant's Prolegomena to Any Future Metaphysics","tradition":"philosophy-ethics","translated_text":null,"word_count":47834}