ON HERACLITUS

Universal motion may be very slow and so sensation be possible. (Radio‑Activity). (1)

Heraclitus says that all is motion. But what is motion? Something which is conceived only as opposed to substance.

Moreover, motion demands two things: a thing that moves and a thing moved, a motor and a mobile.— It needs first, a thing to move because nothing can conceivably move itself. It needs, 2.ly a thing to be moved, for nothing can move itself, as I have said.

Again, to perceive anything, to have any cognition, it is necessary that he that has such a cognition should be something.

That is to say, all motion, all perception, all knowledge, be it changeful and of a thing that changes supposes a substance if by no fact but than that it is here, be it for less than a moment.

Now, having seen that all things are movement, there is one question more to decide. This movement either exists or does not exist. lf it do not exist, still as it may be said of it that it exists, (for it appears to exist) the idea of existence is prior to the idea of movement and existence cannot consist in motion.

(1) Il y a de l’etre dans toute proposition. (Leibnitz).