—whatever term we choose to adopt). This is a logical conclusion simply from taking the conception of difference or distinction and the conception of knowledge quite seriously. The reluctance which people generally feel towards accepting such a conclusion seems to arise from the tendency to translate 'subject' and 'object' straight away into the (supposed) definite individual soul and the (supposed) real world of ordinary thought, which is so largely impregnated with the traditional dualistic philosophy. If we start with the assertion of an absolute difference between the soul as thinking substance and matter as the opposite kind of substance, no wonder if we find a difficulty in explaining the possibility of knowledge. But do we logically need to start with any such assumption? A very slight amount of careful thinking shows us that the 'soul' and the 'thing' are alike mental constructs, inferences, not primitive data of consciousness.
III. Were we to stop here and attempt at once to pass to speculative metaphysics, we might fairly enough be charged with 'solipsism'; but, as I have pointed out, knowledge, in the sense in which we human beings claim to possess knowledge, implies the presence of other selves than our own. Reality means objectivity, i.e., validity and coherence for other selves as well as for self. The existence of other selves than our own is an inference, though an inference speedily arrived at; but the identity of our own self through various experiences is likewise an inference. Since knowledge can be the same for different selves, and since we can communicate our knowledge to them and they to us, there must be an identity underlying all the differences of different selves.
IV. Consistency cannot be ultimately distinguished from truth. The ideal of knowledge is the impossibility of thinking a contradiction, or, to put it positively, the necessity of seeing every part in relation to the whole. This ideal of knowledge is presupposed in every actual step we take in acquiring knowledge; in learning we gradually fill up this form of an orderly system, a unity of the manifold, which is implicit in our thought from the first.
