This reply is, indeed, everywhere made by common sense when left to itself; and if any philosopher answers differently, it is done not through his natural understanding left to itself, but through previously made false presuppositions and lies, which compel him to make such a different answer.
I ask further: Does, then, this infinitely divisible object put itself forth as also determined and completed, and even as included within another infinity? You cannot reply otherwise than: Yes. Hence you contemplate and assert extension to involve a completed and determined infinity; that is, you unite in extension infinity and totality into a fused and concrete unity.
Please make this very important conception still clearer to you by another one, which states the same thing and only emphasizes still more the point at issue. You draw a line from A to B. I ask you: Is not this line divisible infinitely? In going from A to B, did you not, therefore, actually complete an infinite way? Yes. Is it not necessary to assume that in going from any possible point which you may choose in the line A—B to any other possible point, you will meet the same infinity, so that you cannot absolutely go from one point to another without actually realizing that infinity? Hence you must acknowledge that that which seems to the conception utterly impossible and contradictory is actually realized in the contemplation of space.
3. I ask furthermore, how and where is now the infinite divisibility of the body? Have you actually divided infinitely, and experienced the infinite divisibility through the success of your attempt? By no means! You assert merely, that you coulddivide the body infinitely; and thus your assertion, first of all, does state not anything concerning the body itself, but merely something concerning your own faculty; whilst, secondly, this assertion has by no means been corroborated by experience, but grounds itself, if it is true, altogether upon the immediate self-contemplation of that faculty in its inner essence, as an infinite faculty testifying of itself.
Now this infinite faculty is actually contemplated, and is seized and encircled by our glance and placed before it as determined, and hence as the completion and totality of this infinity.
In short, if the faculty is to be contemplated as it is, it must be contemplated as infinite, for it is infinite. If it is to be contemplated, it must be fixed and gathered together, for it is the essence of contemplation to fix. And thus the self-contemplation of the faculty must necessarily become a gathering together of infinity.
Hence, as the last result of our present investigation we have this: Extension in space is nothing but the self-contemplation of the contemplating mind as an infinite faculty.
Let us now gather together what has been made known to us by our undertaken analysis of external perception. It involved, firstly, an affection of the external sense; and since this external sense belongs altogether to the contemplations, and is limited in and to them, it is clear that the contemplating faculty can perceive such an affection or limitation only in and to itself. Hence, in regard to this part, the external perception is a self-contemplation of a determined limitation or affection of the external sense. It involved, secondly, extension, which has clearly shown itself to be a self-contemplation of the contemplating faculty. Hence, external perception, so far as we have as yet been able to learn, goes never beyond the sphere of the contemplating faculty; and it is very easily to be comprehended from the previous analysis how the contemplating faculty, in its state of external perception, is able to say: I feel myself thus and thus limited, although in the same undivided contemplation I behold at the same time my infinite faculty.
But it is not at all to be comprehended, how the contemplating faculty can go beyond this mere perception and say: There exists outside of me, and altogether independently of me, somethingwhich is extended in space, and constituted thus or thus. It is evident now that our analysis of external perception has not yet been closed, and that one of its chief essentials is still lacking.
The immediate fact here is precisely, that the mind goes beyond or out of contemplation, or externalizes; now such a going out from or beyond immediate contemplation and externalizing we have have always called Thinking(which is a mere word-designation to enable us to express ourselves more concisely without always adding the description of the conception).