Motion

There are 6 kinds of motion:

1. Generation

2. Corruption

3. Increase

4. Diminution

5. Transformation

6. Change of place

The other motions then evidently differ from each other, for neither is generation, corruption, nor increase, diminution, nor alteration, change of place, and so of the rest.

Does a thing change independently of other things or motions?

In the case of alteration however, there is some doubt, whether it be not sometimes necessary that what is altered, be so, in respect to some one, of the other motions.

But this is not true, for it happens that

we are altered, as to nearly all the passions, or at least the greater part of them, without any participation of the other motions, for it is not necessary that what is passively moved should be either increased or diminished.

Therefore, transformation is different from the other motions.

If it were the same, 1st. By no increase or diminution necessarily occurring in what is altered.

2nd, By no change taking place in quality.

it would be necessary that what is altered, be forthwith increased or diminished, or follow some of the other motions, but this is not necessary.

Similarly, also, what is increased or moved with any other motion, ought to be altered (in quality);

But some things are increased which are not so altered, as a square is increased when a gnomon[72] is placed about it, but it has not become altered (in quality); and in like manner with other things of this kind, so that these motions will differ from each other.

3. Generic and specific contrariety to motion.

Rest is contrary to motion.

The several rests to the several motions, corruption to generation, diminution to increase, rest in place to change in place.

But change to a contrary place seems especially opposed, as ascent to descent, downwards to upwards.

Still it is not easy, to define the contrary to the remainder of these specified motions, but it seems to have no contrary, unless some one should oppose to this, rest according to quality, or change of quality into its contrary, just as in change of place, rest according to place, or change to a contrary place.

For alteration is the mutation of quality, so that to motion according to quality, will rest according to quality, or change to the contrary of the quality, be opposed.

Thus becoming white is opposed to becoming black, since a change in quality occurs, there being an alteration of quality into contraries.