This ebb and flow of ideas, volitions, and sentiments, have a point in which they are connected, a subject which receives them, remembers them, combines them, and seeks or avoids them; this being, of which we are internally conscious, philosophers have called the me. It is one and identical under all transformations; this unity, this identity, is an indisputable fact which consciousness reveals to us. Who could make us doubt that the me which thinks at the present moment is not the same which thought yesterday, which thought years ago? Notwithstanding the variety of thoughts and desires, the changes of opinion and will, who could deprive us of the firm and deep conviction which we have that we are the same who experience them all, that there is something here within us which is the subject of them all?
34. If there were not something in us permanent in the midst of this variety, the consciousness of the me would be impossible. Memory and combination would also be impossible; for there would be within us only a succession of unconnected phenomena. Thinking is impossible without something which thinks and remains identical under the variety of the forms of thought. There is, therefore, within us a simple subject which connects all the changes which occur in it: there is a substance. In it there is unity: the unity which we only find in corporeal substances after an infinite series of decompositions, is presented to us in the spiritual substance, at the first instant, as a simple internal fact, without which, all the phenomena which we perceive within us are absurd, and all experience of the external world impossible.
Without the unity of the me there can be no sensation, and without sensation no experience of the beings around us.
[CHAPTER VII.]
RELATION OF THE PROPOSITION, I THINK, TO THE SUBSTANTIALITY OF THE ME.
35. The proposition, I think, can have no sense unless we admit that the soul is a substance. Philosophy loses its resting-point, and all that experience within us is a series of unconnected phenomena, incapable of being observed, or subjected to any rule.
36. My present thought is not individually my thought of yesterday, as my thought of to-morrow will not be my thought of to-day. These thoughts, considered in themselves and abstracted from a subject in which they are found, have no connection with one another: perhaps their objects are without any relation to each other, or even contradictory; perhaps the thought of to-day is the denial of the thought of yesterday.
37. The same is true of all thoughts, all acts of the will, of all sentiments, imaginary representations, and sensations, and, in general, of all that I experience within myself. Turning my attention to all internal affections, whatever they may be, I see in them only a series of phenomena, a sort of current of existences passing away and disappearing, some never to return, others to reappear at a different time, expressly presenting this difference. The reappearance is not individual, but similar: the affection which is repeated is not the same, but another resembling it. When the affection returns, I am conscious of its presence at the time, and conscious of its presence at a previous time; this double consciousness constitutes recollection, makes me distinguish between the two affections, and necessarily implies the judgment that one is not the other. There would be no recollection, if the affection recalling were identified with the affection recalled. A thing presents itself, but does not recall itself.