{"collection":"philosophy-ethics","full_text_available":true,"graph_url":"https://unchartedknowledge.5gfusion.net/v2/api/page/wikisource_The_Analysis_of_Mind_Lecture_XIII/graph","html_url":"https://unchartedknowledge.5gfusion.net/v2/page/wikisource_The_Analysis_of_Mind_Lecture_XIII","id":"wikisource_The_Analysis_of_Mind_Lecture_XIII","license":"Public Domain / CC-BY-SA (see source)","rights_basis":"wikisource_site_inclusion_policy","source":"wikisource","source_url":"https://en.wikisource.org/wiki/The_Analysis_of_Mind/Lecture_XIII","summary":null,"tags":["Headers_applying_DefaultSort_key","Subpages"],"text":"The definition of truth and falsehood, which is our topic to-day,\nlies strictly outside our general subject, namely the analysis of\nmind. From the psychological standpoint, there may be different\nkinds of belief, and different degrees of certainty, but there\ncannot be any purely psychological means of distinguishing\nbetween true and false beliefs. A belief is rendered true or\nfalse by relation to a fact, which may lie outside the experience\nof the person entertaining the belief. Truth and falsehood,\nexcept in the case of beliefs about our own minds, depend upon\nthe relations of mental occurrences to outside things, and thus\ntake us beyond the analysis of mental occurrences as they are in\nthemselves. Nevertheless, we can hardly avoid the consideration\nof truth and falsehood. We wish to believe that our beliefs,\nsometimes at least, yield KNOWLEDGE, and a belief does not yield\nknowledge unless it is true. The question whether our minds are\ninstruments of knowledge, and, if so, in what sense, is so vital\nthat any suggested analysis of mind must be examined in relation\nto this question. To ignore this question would be like\ndescribing a chronometer without regard to its accuracy as a\ntime-keeper, or a thermometer without mentioning the fact that it\nmeasures temperature.\n\nMany difficult questions arise in connection with knowledge. It\nis difficult to define knowledge, difficult to decide whether we\nhave any knowledge, and difficult, even if it is conceded that we\nsometimes have knowledge to discover whether we can ever know\nthat we have knowledge in this or that particular case. I shall\ndivide the discussion into four parts:\n\nI. We may regard knowledge, from a behaviourist standpoint, as\nexhibited in a certain kind of response to the environment. This\nresponse must have some characteristics which it shares with\nthose of scientific instruments, but must also have others that\nare peculiar to knowledge. We shall find that this point of view\nis important, but not exhaustive of the nature of knowledge.\n\nII. We may hold that the beliefs that constitute knowledge are\ndistinguished from such as are erroneous or uncertain by\nproperties which are intrinsic either to single beliefs or to\nsystems of beliefs, being in either case discoverable without\nreference to outside fact. Views of this kind have been widely\nheld among philosophers, but we shall find no reason to accept\nthem.\n\nIII. We believe that some beliefs are true, and some false. This\nraises the problem of VERIFIABILITY: are there any circumstances\nwhich can justifiably give us an unusual degree of certainty that\nsuch and such a belief is true? It is obvious that there are\ncircumstances which in fact cause a certainty of this sort, and\nwe wish to learn what we can from examining these circumstances.\n\nIV. Finally, there is the formal problem of defining truth and\nfalsehood, and deriving the objective reference of a proposition\nfrom the meanings of its component words.\n\nWe will consider these four problems in succession.\n\nI. We may regard a human being as an instrument, which makes\nvarious responses to various stimuli. If we observe these\nresponses from outside, we shall regard them as showing knowledge\nwhen they display two characteristics, ACCURACY and\nAPPROPRIATENESS. These two are quite distinct, and even sometimes\nincompatible. If I am being pursued by a tiger, accuracy is\nfurthered by turning round to look at him, but appropriateness by\nrunning away without making any search for further knowledge of\nthe beast. I shall return to the question of appropriateness\nlater; for the present it is accuracy that I wish to consider.\n\nWhen we are viewing a man from the outside, it is not his\nbeliefs, but his bodily movements, that we can observe. His\nknowledge must be inferred from his bodily movements, and\nespecially from what he says and writes. For the present we may\nignore beliefs, and regard a man's knowledge as actually\nconsisting in what he says and does. That is to say, we will\nconstruct, as far as possible, a purely behaviouristic account of\ntruth and falsehood.\n\nIf you ask a boy \"What is twice two?\" and the boy says \"four,\"\nyou take that as prima facie evidence that the boy knows what\ntwice two is. But if you go on to ask what is twice three, twice\nfour, twice five, and so on, and the boy always answers \"four,\"\nyou come to the conclusion that he knows nothing about it.\nExactly similar remarks apply to scientific instruments. I know a\ncertain weather-cock which has the pessimistic habit of always\npointing to the north-east. If you were to see it first on a cold\nMarch day, you would think it an excellent weather-cock; but with\nthe first warm day of spring your confidence would be shaken. The\nboy and the weather-cock have the same defect: they do not vary\ntheir response when the stimulus is varied. A good instrument, or\na person with much knowledge, will give different responses to\nstimuli which differ in relevant ways. This is the first point in\ndefining accuracy of response.\n\nWe will now assume another boy, who also, when you first question\nhim, asserts that twice two is four. But with this boy, instead\nof asking him different questions, you make a practice of asking\nhim the same question every day at breakfast. You find that he\nsays five, or six, or seven, or any other number at random, and\nyou conclude that he also does not know what twice two is, though\nby good luck he answered right the first time. This boy is like a\nweather-cock which, instead of being stuck fast, is always going\nround and round, changing without any change of wind. This boy\nand weather-cock have the opposite defect to that of the previous\npair: they give different responses to stimuli which do not\ndiffer in any relevant way.\n\nIn connection with vagueness in memory, we already had occasion\nto consider the definition of accuracy. Omitting some of the\nniceties of our previous discussion, we may say that an\ninstrument is ACCURATE when it avoids the defects of the two boys\nand weather-cocks, that is to say, when--\n\n(a) It gives different responses to stimuli which differ in\nrelevant ways;\n\n(b) It gives the same response to stimuli which do not differ in\nrelevant ways.\n\nWhat are relevant ways depends upon the nature and purpose of the\ninstrument. In the case of a weather-cock, the direction of the\nwind is relevant, but not its strength; in the case of the boy,\nthe meaning of the words of your question is relevant, but not\nthe loudness of your voice, or whether you are his father or his\nschoolmaster If, however, you were a boy of his own age, that\nwould be relevant, and the appropriate response would be\ndifferent.\n\nIt is clear that knowledge is displayed by accuracy of response\nto certain kinds of stimuli, e.g. examinations. Can we say,\nconversely, that it consists wholly of such accuracy of response?\nI do not think we can; but we can go a certain distance in this\ndirection. For this purpose we must define more carefully the\nkind of accuracy and the kind of response that may be expected\nwhere there is knowledge.\n\nFrom our present point of view, it is difficult to exclude\nperception from knowledge; at any rate, knowledge is displayed by\nactions based upon perception. A bird flying among trees avoids\nbumping into their branches; its avoidance is a response to\nvisual sensations. This response has the characteristic of\naccuracy, in the main, and leads us to say that the bird \"knows,\"\nby sight, what objects are in its neighbourhood. For a\nbehaviourist, this must certainly count as knowledge, however it\nmay be viewed by analytic psychology. In this case, what is\nknown, roughly, is the stimulus; but in more advanced knowledge\nthe stimulus and what is known become different. For example, you\nlook in your calendar and find that Easter will be early next\nyear. Here the stimulus is the calendar, whereas the response\nconcerns the future. Even this can be paralleled among\ninstruments: the behaviour of the barometer has a present\nstimulus but foretells the future, so that the barometer might be\nsaid, in a sense, to know the future. However that may be, the\npoint I am emphasizing as regards knowledge is that what is known\nmay be quite different from the stimulus, and no part of the\ncause of the knowledge-response. It is only in sense-knowledge\nthat the stimulus and what is known are, with qualifications,\nidentifiable. In knowledge of the future, it is obvious that they\nare totally distinct, since otherwise the response would precede\nthe stimulus. In abstract knowledge also they are distinct, since\nabstract facts have no date. In knowledge of the past there are\ncomplications, which we must briefly examine.\n\nEvery form of memory will be, from our present point of view, in\none sense a delayed response. But this phrase does not quite\nclearly express what is meant. If you light a fuse and connect it\nwith a heap of dynamite, the explosion of the dynamite may be\nspoken of, in a sense, as a delayed response to your lighting of\nthe fuse. But that only means that it is a somewhat late portion\nof a continuous process of which the earlier parts have less\nemotional interest. This is not the case with habit. A display of\nhabit has two sorts of causes: (a) the past occurrences which\ngenerated the habit, (b) the present occurrence which brings it\ninto play. When you drop a weight on your toe, and say what you\ndo say, the habit has been caused by imitation of your\nundesirable associates, whereas it is brought into play by the\ndropping of the weight. The great bulk of our knowledge is a\nhabit in this sense: whenever I am asked when I was born, I reply\ncorrectly by mere habit. It would hardly be correct to say that\ngetting born was the stimulus, and that my reply is a delayed\nresponse But in cases of memory this way of speaking would have\nan element of truth. In an habitual memory, the event remembered\nwas clearly an essential part of the stimulus to the formation of\nthe habit. The present stimulus which brings the habit into play\nproduces a different response from that which it would produce if\nthe habit did not exist. Therefore the habit enters into the\ncausation of the response, and so do, at one remove, the causes\nof the habit. It follows that an event remembered is an essential\npart of the causes of our remembering.\n\nIn spite, however, of the fact that what is known is SOMETIMES an\nindispensable part of the cause of the knowledge, this\ncircumstance is, I think, irrelevant to the general question with\nwhich we are concerned, namely What sort of response to what sort\nof stimulus can be regarded as displaying knowledge? There is one\ncharacteristic which the response must have, namely, it must\nconsist of voluntary movements. The need of this characteristic\nis connected with the characteristic of APPROPRIATENESS, which I\ndo not wish to consider as yet. For the present I wish only to\nobtain a clearer idea of the sort of ACCURACY that a\nknowledge-response must have. It is clear from many instances\nthat accuracy, in other cases, may be purely mechanical. The most\ncomplete form of accuracy consists in giving correct answers to\nquestions, an achievement in which calculating machines far\nsurpass human beings. In asking a question of a calculating\nmachine, you must use its language: you must not address it in\nEnglish, any more than you would address an Englishman in\nChinese. But if you address it in the language it understands. it\nwill tell you what is 34521 times 19987, without a moment's\nhesitation or a hint of inaccuracy. We do not say the machine\nKNOWS the answer, because it has no purpose of its own in giving\nthe answer: it does not wish to impress you with its cleverness,\nor feel proud of being such a good machine. But as far as mere\naccuracy goes, the machine leaves nothing to be desired.\n\nAccuracy of response is a perfectly clear notion in the case of\nanswers to questions, but in other cases it is much more obscure.\nWe may say generally that an object whether animate or inanimate,\nis \"sensitive\" to a certain feature of the environment if it\nbehaves differently according to the presence or absence of that\nfeature. Thus iron is sensitive to anything magnetic. But\nsensitiveness does not constitute knowledge, and knowledge of a\nfact which is not sensible is not sensitiveness to that fact, as\nwe have seen in distinguishing the fact known from the stimulus.\nAs soon as we pass beyond the simple case of question and answer,\nthe definition of knowledge by means of behaviour demands the\nconsideration of purpose. A carrier pigeon flies home, and so we\nsay it \"knows\" the way. But if it merely flew to some place at\nrandom, we should not say that it \"knew\" the way to that place,\nany more than a stone rolling down hill knows the way to the\nvalley.\n\nOn the features which distinguish knowledge from accuracy of\nresponse in general, not much can be said from a behaviourist\npoint of view without referring to purpose. But the necessity of\nSOMETHING besides accuracy of response may be brought out by the\nfollowing consideration: Suppose two persons, of whom one\nbelieved whatever the other disbelieved, and disbelieved whatever\nthe other believed. So far as accuracy and sensitiveness of\nresponse alone are concerned, there would be nothing to choose\nbetween these two persons. A thermometer which went down for warm\nweather and up for cold might be just as accurate as the usual\nkind; and a person who always believes falsely is just as\nsensitive an instrument as a person who always believes truly.\nThe observable and practical difference between them would be\nthat the one who always believed falsely would quickly come to a\nbad end. This illustrates once more that accuracy of response to\nstimulus does not alone show knowledge, but must be reinforced by\nappropriateness, i.e. suitability for realizing one's purpose.\nThis applies even in the apparently simple case of answering\nquestions: if the purpose of the answers is to deceive, their\nfalsehood, not their truth, will be evidence of knowledge. The\nproportion of the combination of appropriateness with accuracy in\nthe definition of knowledge is difficult; it seems that both\nenter in, but that appropriateness is only required as regards\nthe general type of response, not as regards each individual\ninstance.\n\nII. I have so far assumed as unquestionable the view that the\ntruth or falsehood of a belief consists in a relation to a\ncertain fact, namely the objective of the belief. This view has,\nhowever, been often questioned. Philosophers have sought some\nintrinsic criterion by which true and false beliefs could be\ndistinguished. I am afraid their chief reason for this search\nhas been the wish to feel more certainty than seems otherwise\npossible as to what is true and what is false. If we could\ndiscover the truth of a belief by examining its intrinsic\ncharacteristics, or those of some collection of beliefs of which\nit forms part, the pursuit of truth, it is thought, would be a\nless arduous business than it otherwise appears to be. But the\nattempts which have been made in this direction are not\nencouraging. I will take two criteria which have been suggested,\nnamely, (1) self-evidence, (2) mutual coherence. If we can show\nthat these are inadequate, we may feel fairly certain that no\nintrinsic criterion hitherto suggested will suffice to\ndistinguish true from false beliefs.\n\n(1) Self-evidence.--Some of our beliefs seem to be peculiarly\nindubitable. One might instance the belief that two and two are\nfour, that two things cannot be in the same place at the same\ntime, nor one thing in two places, or that a particular buttercup\nthat we are seeing is yellow. The suggestion we are to examine is\nthat such: beliefs have some recognizable quality which secures\ntheir truth, and the truth of whatever is deduced from them\naccording to self-evident principles of inference. This theory is\nset forth, for example, by Meinong in his book, \"Ueber die\nErfahrungsgrundlagen unseres Wissens.\"\n\nIf this theory is to be logically tenable, self-evidence must not\nconsist merely in the fact that we believe a proposition. We\nbelieve that our beliefs are sometimes erroneous, and we wish to\nbe able to select a certain class of beliefs which are never\nerroneous. If we are to do this, it must be by some mark which\nbelongs only to certain beliefs, not to all; and among those to\nwhich it belongs there must be none that are mutually\ninconsistent. If, for example, two propositions p and q were\nself-evident, and it were also self-evident that p and q could\nnot both be true, that would condemn self-evidence as a guarantee\nof truth. Again, self-evidence must not be the same thing as the\nabsence of doubt or the presence of complete certainty. If we are\ncompletely certain of a proposition, we do not seek a ground to\nsupport our belief. If self-evidence is alleged as a ground of\nbelief, that implies that doubt has crept in, and that our\nself-evident proposition has not wholly resisted the assaults of\nscepticism. To say that any given person believes some things so\nfirmly that he cannot be made to doubt them is no doubt true.\nSuch beliefs he will be willing to use as premisses in reasoning,\nand to him personally they will seem to have as much evidence as\nany belief can need. But among the propositions which one man\nfinds indubitable there will be some that another man finds it\nquite possible to doubt. It used to seem self-evident that there\ncould not be men at the Antipodes, because they would fall off,\nor at best grow giddy from standing on their heads. But New\nZealanders find the falsehood of this proposition self-evident.\nTherefore, if self-evidence is a guarantee of truth, our\nancestors must have been mistaken in thinking their beliefs about\nthe Antipodes self-evident. Meinong meets this difficulty by\nsaying that some beliefs are falsely thought to be self-evident,\nbut in the case of others it is self-evident that they are\nself-evident, and these are wholly reliable. Even this, however,\ndoes not remove the practical risk of error, since we may\nmistakenly believe it self-evident that a certain belief is\nself-evident. To remove all risk of error, we shall need an\nendless series of more and more complicated self-evident beliefs,\nwhich cannot possibly be realized in practice. It would seem,\ntherefore, that self-evidence is useless as a practical criterion\nfor insuring truth.\n\nThe same result follows from examining instances. If we take the\nfour instances mentioned at the beginning of this discussion, we\nshall find that three of them are logical, while the fourth is a\njudgment of perception. The proposition that two and two are four\nfollows by purely logical deduction from definitions: that means\nthat its truth results, not from the properties of objects, but\nfrom the meanings of symbols. Now symbols, in mathematics, mean\nwhat we choose; thus the feeling of self-evidence, in this case,\nseems explicable by the fact that the whole matter is within our\ncontrol. I do not wish to assert that this is the whole truth\nabout mathematical propositions, for the question is complicated,\nand I do not know what the whole truth is. But I do wish to\nsuggest that the feeling of self-evidence in mathematical\npropositions has to do with the fact that they are concerned with\nthe meanings of symbols, not with properties of the world such as\nexternal observation might reveal.\n\nSimilar considerations apply to the impossibility of a thing\nbeing in two places at once, or of two things being in one place\nat the same time. These impossibilities result logically, if I am\nnot mistaken, from the definitions of one thing and one place.\nThat is to say, they are not laws of physics, but only part of\nthe intellectual apparatus which we have manufactured for\nmanipulating physics. Their self-evidence, if this is so, lies\nmerely in the fact that they represent our decision as to the use\nof words, not a property of physical objects.\n\nJudgments of perception, such as \"this buttercup is yellow,\" are\nin a quite different position from judgments of logic, and their\nself-evidence must have a different explanation. In order to\narrive at the nucleus of such a judgment, we will eliminate, as\nfar as possible, the use of words which take us beyond the\npresent fact, such as \"buttercup\" and \"yellow.\" The simplest kind\nof judgment underlying the perception that a buttercup is yellow\nwould seem to be the perception of similarity in two colours seen\nsimultaneously. Suppose we are seeing two buttercups, and we\nperceive that their colours are similar. This similarity is a\nphysical fact, not a matter of symbols or words; and it certainly\nseems to be indubitable in a way that many judgments are not.\n\nThe first thing to observe, in regard to such judgments, is that\nas they stand they are vague. The word \"similar\" is a vague word,\nsince there are degrees of similarity, and no one can say where\nsimilarity ends and dissimilarity begins. It is unlikely that our\ntwo buttercups have EXACTLY the same colour, and if we judged\nthat they had we should have passed altogether outside the region\nof self-evidence. To make our proposition more precise, let us\nsuppose that we are also seeing a red rose at the same time. Then\nwe may judge that the colours of the buttercups are more similar\nto each other than to the colour of the rose. This judgment seems\nmore complicated, but has certainly gained in precision. Even\nnow, however, it falls short of complete precision, since\nsimilarity is not prima facie measurable, and it would require\nmuch discussion to decide what we mean by greater or less\nsimilarity. To this process of the pursuit of precision there is\nstrictly no limit.\n\nThe next thing to observe (although I do not personally doubt\nthat most of our judgments of perception are true) is that it is\nvery difficult to define any class of such judgments which can be\nknown, by its intrinsic quality, to be always exempt from error.\nMost of our judgments of perception involve correlations, as when\nwe judge that a certain noise is that of a passing cart. Such\njudgments are all obviously liable to error, since there is no\ncorrelation of which we have a right to be certain that it is\ninvariable. Other judgments of perception are derived from\nrecognition, as when we say \"this is a buttercup,\" or even merely\n\"this is yellow.\" All such judgments entail some risk of error,\nthough sometimes perhaps a very small one; some flowers that look\nlike buttercups are marigolds, and colours that some would call\nyellow others might call orange. Our subjective certainty is\nusually a result of habit, and may lead us astray in\ncircumstances which are unusual in ways of which we are unaware.\n\nFor such reasons, no form of self-evidence seems to afford an\nabsolute criterion of truth. Nevertheless, it is perhaps true\nthat judgments having a high degree of subjective certainty are\nmore apt to be true than other judgments. But if this be the\ncase, it is a result to be demonstrated, not a premiss from which\nto start in defining truth and falsehood. As an initial\nguarantee, therefore, neither self-evidence nor subjective\ncertainty can be accepted as adequate.\n\n(2) Coherence.--Coherence as the definition of truth is advocated\nby idealists, particularly by those who in the main follow Hegel.\nIt is set forth ably in Mr. Joachim's book, \"The Nature of Truth\"\n(Oxford, 1906). According to this view, any set of propositions\nother than the whole of truth can be condemned on purely logical\ngrounds, as internally inconsistent; a single proposition, if it\nis what we should ordinarily call false, contradicts itself\nirremediably, while if it is what we should ordinarily call true,\nit has implications which compel us to admit other propositions,\nwhich in turn lead to others, and so on, until we find ourselves\ncommitted to the whole of truth. One might illustrate by a very\nsimple example: if I say \"so-and-so is a married man,\" that is\nnot a self-subsistent proposition. We cannot logically conceive\nof a universe in which this proposition constituted the whole of\ntruth. There must be also someone who is a married woman, and who\nis married to the particular man in question. The view we are\nconsidering regards everything that can be said about any one\nobject as relative in the same sort of way as \"so-and-so is a\nmarried man.\" But everything, according to this view, is\nrelative, not to one or two other things, but to all other\nthings, so that from one bit of truth the whole can be inferred.\n\nThe fundamental objection to this view is logical, and consists\nin a criticism of its doctrine as to relations. I shall omit this\nline of argument, which I have developed elsewhere. For the\nmoment I will content myself with saying that the powers of logic\nseem to me very much less than this theory supposes. If it were\ntaken seriously, its advocates ought to profess that any one\ntruth is logically inferable from any other, and that, for\nexample, the fact that Caesar conquered Gaul, if adequately\nconsidered, would enable us to discover what the weather will be\nto-morrow. No such claim is put forward in practice, and the\nnecessity of empirical observation is not denied; but according\nto the theory it ought to be.\n\nAnother objection is that no endeavour is made to show that we\ncannot form a consistent whole composed partly or wholly of false\npropositions, as in a novel. Leibniz's conception of many\npossible worlds seems to accord much better with modern logic and\nwith the practical empiricism which is now universal. The attempt\nto deduce the world by pure thought is attractive, and in former\ntimes was largely supposed capable of success. But nowadays most\nmen admit that beliefs must be tested by observation, and not\nmerely by the fact that they harmonize with other beliefs. A\nconsistent fair-ytale is a different thing from truth, however\nelaborate it may be. But to pursue this topic would lead us into\ndifficult technicalities; I shall therefore assume, without\nfurther argument, that coherence is not sufficient as a\ndefinition of truth.\n\nIII. Many difficult problems arise as regards the verifiability\nof beliefs. We believe various things, and while we believe them\nwe think we know them. But it sometimes turns out that we were\nmistaken, or at any rate we come to think we were. We must be\nmistaken either in our previous opinion or in our subsequent\nrecantation; therefore our beliefs are not all correct, and there\nare cases of belief which are not cases of knowledge. The\nquestion of verifiability is in essence this: can we discover any\nset of beliefs which are never mistaken or any test which, when\napplicable, will always enable us to discriminate between true\nand false beliefs? Put thus broadly and abstractly, the answer\nmust be negative. There is no way hitherto discovered of wholly\neliminating the risk of error, and no infallible criterion. If we\nbelieve we have found a criterion, this belief itself may be\nmistaken; we should be begging the question if we tried to test\nthe criterion by applying the criterion to itself.\n\nBut although the notion of an absolute criterion is chimerical,\nthere may be relative criteria, which increase the probability of\ntruth. Common sense and science hold that there are. Let us see\nwhat they have to say.\n\nOne of the plainest cases of verification, perhaps ultimately the\nonly case, consists in the happening of something expected. You\ngo to the station believing that there will be a train at a\ncertain time; you find the train, you get into it, and it starts\nat the expected time This constitutes verification, and is a\nperfectly definite experience. It is, in a sense, the converse of\nmemory instead of having first sensations and then images\naccompanied by belief, we have first images accompanied by belief\nand then sensations. Apart from differences as to the time-order\nand the accompanying feelings, the relation between image and\nsensation is closely similar in the two cases of memory and\nexpectation; it is a relation of similarity, with difference as\nto causal efficacy--broadly, the image has the psychological but\nnot the physical effects that the sensation would have. When an\nimage accompanied by an expectation-belief is thus succeeded by a\nsensation which is the \"meaning\" of the image, we say that the\nexpectation-belief has been verified. The experience of\nverification in this sense is exceedingly familiar; it happens\nevery time that accustomed activities have results that are not\nsurprising, in eating and walking and talking and all our daily\npursuits.\n\nBut although the experience in question is common, it is not\nwholly easy to give a theoretical account of it. How do we know\nthat the sensation resembles the previous image? Does the image\npersist in presence of the sensation, so that we can compare the\ntwo? And even if SOME image does persist, how do we know that it\nis the previous image unchanged? It does not seem as if this line\nof inquiry offered much hope of a successful issue. It is better,\nI think, to take a more external and causal view of the relation\nof expectation to expected occurrence. If the occurrence, when it\ncomes, gives us the feeling of expectedness, and if the\nexpectation, beforehand, enabled us to act in a way which proves\nappropriate to the occurrence, that must be held to constitute\nthe maximum of verification. We have first an expectation, then a\nsensation with the feeling of expectedness related to memory of\nthe expectation. This whole experience, when it occurs, may be\ndefined as verification, and as constituting the truth of the\nexpectation. Appropriate action, during the period of\nexpectation, may be regarded as additional verification, but is\nnot essential. The whole process may be illustrated by looking up\na familiar quotation, finding it in the expected words, and in\nthe expected part of the book. In this case we can strengthen the\nverification by writing down beforehand the words which we expect\nto find.\n\nI think all verification is ultimately of the above sort. We\nverify a scientific hypothesis indirectly, by deducing\nconsequences as to the future, which subsequent experience\nconfirms. If somebody were to doubt whether Caesar had crossed\nthe Rubicon, verification could only be obtained from the future.\nWe could proceed to display manuscripts to our historical\nsceptic, in which it was said that Caesar had behaved in this\nway. We could advance arguments, verifiable by future experience,\nto prove the antiquity of the manuscript from its texture,\ncolour, etc. We could find inscriptions agreeing with the\nhistorian on other points, and tending to show his general\naccuracy. The causal laws which our arguments would assume could\nbe verified by the future occurrence of events inferred by means\nof them. The existence and persistence of causal laws, it is\ntrue, must be regarded as a fortunate accident, and how long it\nwill continue we cannot tell. Meanwhile verification remains\noften practically possible. And since it is sometimes possible,\nwe can gradually discover what kinds of beliefs tend to be\nverified by experience, and what kinds tend to be falsified; to\nthe former kinds we give an increased degree of assent, to the\nlatter kinds a diminished degree. The process is not absolute or\ninfallible, but it has been found capable of sifting beliefs and\nbuilding up science. It affords no theoretical refutation of the\nsceptic, whose position must remain logically unassailable; but\nif complete scepticism is rejected, it gives the practical method\nby which the system of our beliefs grows gradually towards the\nunattainable ideal of impeccable knowledge.\n\nIV. I come now to the purely formal definition of the truth or\nfalsehood of a belief. For this definition it is necessary first\nof all to consider the derivation of the objective reference of a\nproposition from the meanings of its component words or images.\n\nJust as a word has meaning, so a proposition has an objective\nreference. The objective reference of a proposition is a function\n(in the mathematical sense) of the meanings of its component\nwords. But the objective reference differs from the meaning of a\nword through the duality of truth and falsehood. You may believe\nthe proposition \"to-day is Tuesday\" both when, in fact, to-day is\nTuesday, and when to-day is not Tuesday. If to-day is not\nTuesday, this fact is the objective of your belief that to-day is\nTuesday. But obviously the relation of your belief to the fact is\ndifferent in this case from what it is in the case when to-day is\nTuesday. We may say, metaphorically, that when to-day is Tuesday,\nyour belief that it is Tuesday points TOWARDS the fact, whereas\nwhen to-day is not Tuesday your belief points AWAY FROM the fact.\nThus the objective reference of a belief is not determined by the\nfact alone, but by the direction of the belief towards or away\nfrom the fact. If, on a Tuesday, one man believes that it is\nTuesday while another believes that it is not Tuesday, their\nbeliefs have the same objective, namely the fact that it is\nTuesday but the true belief points towards the fact while the\nfalse one points away from it. Thus, in order to define the\nreference of a proposition we have to take account not only of\nthe objective, but also of the direction of pointing, towards the\nobjective in the case of a true proposition and away from it in\nthe case of a false one.\n\nThis mode of stating the nature of the objective reference of a\nproposition is necessitated by the circumstance that there are\ntrue and false propositions, but not true and false facts. If\nto-day is Tuesday, there is not a false objective \"to-day is not\nTuesday,\" which could be the objective of the false belief\n\"to-day is not Tuesday.\" This is the reason why two beliefs which\nare each other's contradictories have the same objective. There\nis, however, a practical inconvenience, namely that we cannot\ndetermine the objective reference of a proposition, according to\nthis definition, unless we know whether the proposition is true\nor false. To avoid this inconvenience, it is better to adopt a\nslightly different phraseology, and say: The \"meaning\" of the\nproposition \"to-day is Tuesday\" consists in pointing to the fact\n\"to-day is Tuesday\" if that is a fact, or away from the fact\n\"to-day is not Tuesday\" if that is a fact. The \"meaning\" of the\nproposition \"to-day is not Tuesday\" will be exactly the opposite.\nBy this hypothetical form we are able to speak of the meaning of\na proposition without knowing whether it is true or false.\nAccording to this definition, we know the meaning of a\nproposition when we know what would make it true and what would\nmake it false, even if we do not know whether it is in fact true\nor false.\n\nThe meaning of a proposition is derivative from the meanings of\nits constituent words. Propositions occur in pairs, distinguished\n(in simple cases) by the absence or presence of the word \"not.\"\nTwo such propositions have the same objective, but opposite\nmeanings: when one is true, the other is false, and when one is\nfalse, the other is true.\n\nThe purely formal definition of truth and falsehood offers little\ndifficulty. What is required is a formal expression of the fact\nthat a proposition is true when it points towards its objective,\nand false when it points away from it, In very simple cases we\ncan give a very simple account of this: we can say that true\npropositions actually resemble their objectives in a way in which\nfalse propositions do not. But for this purpose it is necessary\nto revert to image-propositions instead of word-propositions. Let\nus take again the illustration of a memory-image of a familiar\nroom, and let us suppose that in the image the window is to the\nleft of the door. If in fact the window is to the left of the\ndoor, there is a correspondence between the image and the\nobjective; there is the same relation between the window and the\ndoor as between the images of them. The image-memory consists of\nthe image of the window to the left of the image of the door.\nWhen this is true, the very same relation relates the terms of\nthe objective (namely the window and the door) as relates the\nimages which mean them. In this case the correspondence which\nconstitutes truth is very simple.\n\nIn the case we have just been considering the objective consists\nof two parts with a certain relation (that of left-to-right), and\nthe proposition consists of images of these parts with the very\nsame relation. The same proposition, if it were false, would have\na less simple formal relation to its objective. If the\nimage-proposition consists of an image of the window to the left\nof an image of the door, while in fact the window is not to the\nleft of the door, the proposition does not result from the\nobjective by the mere substitution of images for their\nprototypes. Thus in this unusually simple case we can say that a\ntrue proposition \"corresponds\" to its objective in a formal sense\nin which a false proposition does not. Perhaps it may be possible\nto modify this notion of formal correspondence in such a way as\nto be more widely applicable, but if so, the modifications\nrequired will be by no means slight. The reasons for this must\nnow be considered.\n\nTo begin with, the simple type of correspondence we have been\nexhibiting can hardly occur when words are substituted for\nimages, because, in word-propositions, relations are usually\nexpressed by words, which are not themselves relations. Take such\na proposition as \"Socrates precedes Plato.\" Here the word\n\"precedes\" is just as solid as the words \"Socrates\" and \"Plato\";\nit MEANS a relation, but is not a relation. Thus the objective\nwhich makes our proposition true consists of TWO terms with a\nrelation between them, whereas our proposition consists of THREE\nterms with a relation of order between them. Of course, it would\nbe perfectly possible, theoretically, to indicate a few chosen\nrelations, not by words, but by relations between the other\nwords. \"Socrates-Plato\" might be used to mean \"Socrates precedes\nPlato\"; \"PlaSocrates-to\" might be used to mean \"Plato was born\nbefore Socrates and died after him\"; and so on. But the\npossibilities of such a method would be very limited. For aught I\nknow, there may be languages that use it, but they are not among\nthe languages with which I am acquainted. And in any case, in\nview of the multiplicity of relations that we wish to express, no\nlanguage could advance far without words for relations. But as\nsoon as we have words for relations, word-propositions have\nnecessarily more terms than the facts to which they refer, and\ncannot therefore correspond so simply with their objectives as\nsome image-propositions can.\n\nThe consideration of negative propositions and negative facts\nintroduces further complications. An image-proposition is\nnecessarily positive: we can image the window to the left of the\ndoor, or to the right of the door, but we can form no image of\nthe bare negative \"the window not to the left of the door.\" We\ncan DISBELIEVE the image-proposition expressed by \"the window to\nthe left of the door,\" and our disbelief will be true if the\nwindow is not to the left of the door. But we can form no image\nof the fact that the window is not to the left of the door.\nAttempts have often been made to deny such negative facts, but,\nfor reasons which I have given elsewhere, I believe these\nattempts to be mistaken, and I shall assume that there are\nnegative facts.\n\nWord-propositions, like image-propositions, are always positive\nfacts. The fact that Socrates precedes Plato is symbolized in\nEnglish by the fact that the word \"precedes\" occurs between the\nwords \"Socrates\" and \"Plato.\" But we cannot symbolize the fact\nthat Plato does not precede Socrates by not putting the word\n\"precedes\" between \"Plato\" and \"Socrates.\" A negative fact is not\nsensible, and language, being intended for communication, has to\nbe sensible. Therefore we symbolize the fact that Plato does not\nprecede Socrates by putting the words \"does not precede\" between\n\"Plato\" and \"Socrates.\" We thus obtain a series of words which is\njust as positive a fact as the series \"Socrates precedes Plato.\"\nThe propositions asserting negative facts are themselves positive\nfacts; they are merely different positive facts from those\nasserting positive facts.\n\nWe have thus, as regards the opposition of positive and negative,\nthree different sorts of duality, according as we are dealing\nwith facts, image-propositions, or word-propositions. We have,\nnamely:\n\n(1) Positive and negative facts;\n\n(2) Image-propositions, which may be believed or disbelieved, but\ndo not allow any duality of content corresponding to positive and\nnegative facts;\n\n(3) Word-propositions, which are always positive facts, but are\nof two kinds: one verified by a positive objective, the other by\na negative objective.\n\nOwing to these complications, the simplest type of correspondence\nis impossible when either negative facts or negative propositions\nare involved.\n\nEven when we confine ourselves to relations between two terms\nwhich are both imaged, it may be impossible to form an\nimage-proposition in which the relation of the terms is\nrepresented by the same relation of the images. Suppose we say\n\"Caesar was 2,000 years before Foch,\" we express a certain\ntemporal relation between Caesar and Foch; but we cannot allow\n2,000 years to elapse between our image of Caesar and our image\nof Foch. This is perhaps not a fair example, since \"2,000 years\nbefore\" is not a direct relation. But take a case where the\nrelation is direct, say, \"the sun is brighter than the moon.\" We\ncan form visual images of sunshine and moonshine, and it may\nhappen that our image of the sunshine is the brighter of the two,\nbut this is by no means either necessary or sufficient. The act\nof comparison, implied in our judgment, is something more than\nthe mere coexistence of two images, one of which is in fact\nbrighter than the other. It would take us too far from our main\ntopic if we were to go into the question what actually occurs\nwhen we make this judgment. Enough has been said to show that the\ncorrespondence between the belief and its objective is more\ncomplicated in this case than in that of the window to the left\nof the door, and this was all that had to be proved.\n\nIn spite of these complications, the general nature of the formal\ncorrespondence which makes truth is clear from our instances. In\nthe case of the simpler kind of propositions, namely those that I\ncall \"atomic\" propositions, where there is only one word\nexpressing a relation, the objective which would verify our\nproposition, assuming that the word \"not\" is absent, is obtained\nby replacing each word by what it means, the word meaning a\nrelation being replaced by this relation among the meanings of\nthe other words. For example, if the proposition is \"Socrates\nprecedes Plato,\" the objective which verifies it results from\nreplacing the word \"Socrates\" by Socrates, the word \"Plato\" by\nPlato, and the word \"precedes\" by the relation of preceding\nbetween Socrates and Plato. If the result of this process is a\nfact, the proposition is true; if not, it is false. When our\nproposition is \"Socrates does not precede Plato,\" the conditions\nof truth and falsehood are exactly reversed. More complicated\npropositions can be dealt with on the same lines. In fact, the\npurely formal question, which has occupied us in this last\nsection, offers no very formidable difficulties.\n\nI do not believe that the above formal theory is untrue, but I do\nbelieve that it is inadequate. It does not, for example, throw\nany light upon our preference for true beliefs rather than false\nones. This preference is only explicable by taking account of the\ncausal efficacy of beliefs, and of the greater appropriateness of\nthe responses resulting from true beliefs. But appropriateness\ndepends upon purpose, and purpose thus becomes a vital part of\ntheory of knowledge.","title":"The Analysis of Mind/Lecture XIII","tradition":"philosophy-ethics","translated_text":null,"word_count":7506}