Page:Philosophical Review Volume 1.djvu/31

Rh we are dealing not with sensible realities, but with abstractions. Now, space and time are not complete individuals. If indeed space were, as the late Professor Clifford rashly imagined it might be, a vast sphere, or if it were divided up into a number of individual spaces, we might picture it as complete; but as there is no limit to its divisibility or extensibility, we can present it to ourselves only by successively generating its parts and combining them into a relative whole. It is the same with time, which has no beginning and no end. The perception of a particular space or time thus exists for us only in the process by which it is generated and united with other spaces or times. The synthetic activity exercised by the mind in this case takes the form of a successive synthesis of homogeneous units, for every part of space or time is precisely alike. This form of synthesis lies at the basis of all our sensible presentations, for obviously no sensible object can escape from the conditions of our perceptive experience. The consciousness of this mode of synthetic activity is the consciousness of extensive quantity, and this consciousness is presupposed in all our mathematical determinations of phenomena.

There is a second principle of experience which we can lay down. Not only are all phenomena extensive quanta, but they are also intensive quanta. Kant finds this new characteristic also bound up with the conditions of sensible perception. The conception of reality, as we have seen, is of that which is complete in itself, or absolutely individual, but of no such reality can we have any sensible experience. The objects of our sensible experience have not an absolute, but only a relative reality. Complete reality would be infinite, whereas the reality we know, as sensible, possesses only a limited amount of reality. We can represent any sensible object as real only by conceiving it as limited by an opposite reality. Thus there lies at the foundation of every perception a synthetic process by which we picture reality as ascending from zero without reaching infinity, and combine the elements of reality so generated in a definite degree. As the real must be represented as in time, it is impossible to present any reality as infinitely small or infinitely large. The