4. But this science, this Dialectic essential to all the three classes alike, what, in sum, is it? It is the Method, or Discipline, that brings with it the power of pronouncing with final truth upon the nature and relation of things- what each is, how it differs from others, what common quality all have, to what Kind each belongs and in what rank each stands in its Kind and whether its Being is Real-Being, and how many Beings there are, and how many non-Beings to be distinguished from Beings.