Aristotle (Phys. V. 1) then goes on to movement as realized in a thing, to change (μεταβολή) or to the physical processes—while before we had pure movement. “In movement there is first something which moves, also something which is moved, and the time in which it is moved; besides these, that from which, and that into which it is moved.” (Cf. _supra_, p. 141.) “For all motion is from something and into something; but there is a difference between that which is first moved and that into which and from which it is moved, as, for instance, wood, warmth and cold. The motion is in the wood and not in the form; for neither form nor place, nor quantity moves or is moved, but” (in the order in which they follow) “there is that which is moved and that which moves, and that into which it is moved. That to which movement is made, more than that out of which movement is made, is named change. Hence to pass into non-being is also change, although what passes away is changed from Being: and generation is a mutation into Being, even though it is from non-being.” The remark is to be interpreted as meaning that for the first time in real becoming motion, _i.e._ in change, the relation _whereto_ enters, while the relation _wherefrom_ is that in which change is still the mere ideal motion. Besides this first form of difference between motion and change, Aristotle further gives another, since he divides change into three: “into change from a subject (ἐξ ὑποκειμένον) into a subject; or from a subject into a non-subject; or from a non-subject into a subject.” The fourth, “from a non-subject into a non-subject,” which may also appear in the general division, “is no mutation, for it contains no opposition.” It may certainly be merely thought or ideal, but Aristotle indicates the actual phenomenon. “The mutation from a non-subject into a subject is generation (γένεσις); that from a subject into a non-subject is corruption (φθορά); that from a subject into a subject, is motion as such;” because that which is transformed remains the same, there is no becoming-another of the actual, but a merely formal becoming-another. This opposition of the materialized motion as mutation, and of merely formal motion, is noteworthy.