That which changes either changes accidentally, as when the cultured
walks; or is said to change in general because something in it changes, as in the case of things which change in their parts; the body becomes healthy because the eye does.
But there is something which is moved directly per se, i.e. the essentially movable. The same applies to that which moves, for it moves sometimes accidentally, sometimes partially, and sometimes per se. There is something that moves directly, and something that is moved; and also a time in which, and something from which, and something into which it is moved. But the forms and modifications and place into which moving things are moved are immovable; e.g. knowledge and warmth. It is not warmth that is motion, but the process of warming.
Non-accidental change is not found in all things, but only between contraries and intermediates and contradictories. We can convince ourselves of this by means of induction. That which changes changes either from positive into positive, or from negative into negative, or from positive into negative, or from negative into positive.
By positive
I mean that which is denoted by an affirmation. Thus there must be three forms of change; for that which is from negative into negative is not change, because they are neither contraries nor contradictories, since they entail no opposition. The change from the negative into its contradictory positive is generation—absolute change absolute generation, and qualified change qualified generation; and the change from the positive to the negative is destruction—absolute change absolute destruction, and qualified change qualified destruction. Footnote 1The change from positive to positive is omitted here (but cf. sect. 7). Aristotle no doubt intended to use it as an example of non-substantial change, e.g. from poor man
to rich man
; but since this can be regarded as change from poor man
to not-poor man,
or not-rich man
to rich man,
he includes it as a qualified type of substantial change.
Now if what is not
has several meanings, and neither that which implies a combination or separation of terms, Footnote 2i.e., falsity. Cf. Aristot. Met. 9.10.1. nor that which relates to potentiality and is opposed to unqualified Being, admits of motion (not-white
or not-good,
however, admits of motion accidentally, because not-white
may be a man; but that which is not so-and-so
in an absolute sense does not admit of it at all), then what is not
cannot be moved. If this is so, generation cannot be motion; for it is what is not
that is generated.
For even if the generation is in the highest degree accidental, still it is true to say that not-being is predicable of that which is generated absolutely. And the argument applies similarly to rest. Thus not only do these difficult conclusions follow, but also that everything which is moved is in a place, whereas what is not
is not in a place; for then it would be somewhere. Nor is destruction motion; for the contrary of motion is motion or rest, but the contrary of destruction is generation.
And since every motion is a kind of change, and the three kinds of change are those which we have described, Footnote 3sect. 3. and of these those which relate to generation and destruction are not motions, and these are the changes between contradictories, the change from positive to positive must alone be motion. The subjects are either contraries or intermediates (for privative terms may also be regarded as contraries) and are denoted by a positive term—e.g. naked
or toothless
or black.