[3] B. 521, M. 308.
CHAPTER V
TIME AND INNER SENSE
The arguments by which Kant seeks to show that time is not a determination of things in themselves but only a form of perception are, mutatis mutandis, identical with those used in his treatment of space.[1] They are, therefore, open to the same criticisms, and need no separate consideration.
Time, however, according to Kant, differs from space in one important respect. It is the form not of outer but of inner sense; in other words, while space is the form under which we perceive things, time is the form under which we perceive ourselves. It is upon this difference that attention must be concentrated. The existence of the difference at all is upon general grounds surprising. For since the arguments by which Kant establishes the character of time as a form of perception run pari passu with those used in the case of space, we should expect time, like space, to be a form under which we perceive things; and, as a matter of fact, it will be found that the only argument used to show that time is the form of inner, as opposed to outer, sense is not only independent of Kant's general theory of forms of sense, but is actually inconsistent with it.[2] Before, however, we attempt to decide Kant's right to distinguish between inner and outer sense, we must consider the facts which were before Kant's mind in making the distinction.
These facts and, to a large extent, the frame of mind in which Kant approached them, find expression in the passage in Locke's Essay, which explains the distinction between 'ideas of sensation' and 'ideas of reflection'.
"Whence has it [i. e. the mind] all the materials of reason and knowledge? To this I answer, in one word, from experience.... Our observation, employed either about external, sensible objects, or about the internal operations of our minds, perceived and reflected on, by ourselves, is that which supplies our understandings with all the materials of thinking. These two are the fountains of knowledge...."
"First, Our senses, conversant about particular sensible objects, do convey into the mind several distinct perceptions of things, according to those various ways, wherein those objects do affect them: and thus we come by those ideas we have of Yellow, White, Heat, Cold, Soft, Hard, Bitter, Sweet, and all those, which we call sensible qualities; which, when I say the senses convey into the mind, I mean, they, from external objects, convey into the mind what produces there those perceptions. This great source of most of the ideas we have, depending wholly upon our senses, and derived by them to the understanding, I call sensation."