LECTURE 9 (229 b 23-230 a 18)

THE CONTRARIETY OF REST TO MOTION AND OF REST TO REST

             727. After the Philosopher has treated the contrariety of motions, he here treats the contrariety of states of rest. First he explains the contrariety of rest to motions, and secondly to mutations, where he says, 'Of all things that have . . .' (230 a 7).

             Concerning the first part he makes two points. First he shows that rest is contrary to motion. Secondly, where he says, '. . . and motion of one kind . . .' (229 b 26), he shows what states of rest are contrary to what motions.

             He says, therefore, first that not only motion, but also rest, seems to be contrary to motion. Hence it must be determined how rest is contrary to motion. In the simple and proper and strict sense motion is contrary to motion. But rest is also opposed to motion, since it is a privation of motion, and a privation is in some way a contrary. For act and privation is the first contrariety, as is said in Metaphysics, X. In all contraries the relation [ratio] of act and privation is found. For one of the contraries is always, as it were, a privation in respect to the other, for example, white in respect to black, and bitter in respect to sweet.

             728. Next where he says, '. . . and motion of one kind . . .' (229 b 26), he shows what rest is contrary to what motion.

             Concerning this he makes three points. First he raises the problem. Secondly, where he says, 'It is surely clear . . .' (229 b 29), he determines the truth in this matter. Thirdly, where he says, '. . . and (2) the motion to which . . .' (230 a 2), he proves his position.

             In the problem which he raises, one thing is presupposed, namely, not every state of rest is opposed to every motion. Rather some states of rest are opposed to some motions. For example, rest in place is opposed to motion in place. But since this is stated universally, a further question must be asked. Is motion to white (i.e. becoming white) or motion from white (i.e. becoming black) opposed to rest in the terminus white?

             729. Next where he says, 'lt is surely clear . . .' (229 b 29), he determines the truth. He does this first in regard to the contrariety of motion to rest, and secondly in regard to the contrariety of rest to rest, where he says, 'At the same time . . .' (229 b 32).

             He says, therefore, first that since motion occurs between two subjects, that is, between two affirmative termini, then rest in the terminus is contrary to motion from that terminus to its contrary. For example, rest in whiteness is contrary to motion from white to black. Furthermore, rest in the other contrary is contrary to motion from that contrary to the first one. For example, rest in blackness is contrary to motion from black to white.

             730. Next where he says, 'At the same time . . .' (229 b 32), he treats the contrariety of rest to rest.

             He says that states of rest in contrary termini are contrary to each other. For if the motions are contrary to each other, it is impossible for the states of rest not to be opposed to each other. He gives an example of how states of rest in opposite termini are opposed. Rest in health is opposed to rest in sickness.

             731. Next where he says, '. . . and (2) the motion to which . . .' (230 a 2), he proves what he has said about the contrariety of rest to motion.

             He says that rest in health is opposed to motion from health to sickness. For it would be irrational for rest in health to be opposed to motion from sickness to health.

             He proves this as follows. When there is motion to a terminus, its arrival at that terminus is not opposed to the motion, but rather is its completion and perfection. He shows as follows that rest in the terminus to which is the perfection of motion. Rest occurs together with motion, for to be moved to a terminus is the same thing as becoming a state of rest. Hence, since motion is the cause of that state of rest, it cannot be opposed to it, because nothing causes its opposite. But it is necessary that either rest in the terminus to which or rest in the terminus from which be contrary to motion. For it cannot be said that rest in some other species is contrary to motion or rest; for example, that rest in whiteness is contrary to rest in health or to motion to health. Therefore, since rest in the terminus to which is not contrary to motion, it follows that rest in the terminus from which is contrary to motion.

             732. Next where he says, 'Of all things that have . . .' (230 a 7), he determines the contrariety of rest to mutations.

             Concerning this he makes three points. First he summarizes what he has already said about the contrariety of mutations. Secondly, where he says, 'So, too, of such things . . .' (230 a 10), he shows that non-mutation, but not rest, is opposed to mutation. Thirdly, where he says, '. . . we must say that it is . . .' (230 a 17), he shows how non-mutation is contrary to mutation.

             Hence he first summarizes what was said above. In mutations in which there is no contrariety in the termini, for example, in the generation and corruption of substance, the opposition arises from the arrival at and removal from the same terminus. For mutation from some terminus is opposed to mutation to that same terminus. Thus mutation from being, or corruption, is opposed to mutation to being, or generation. Nevertheless, neither of these is a motion.

             733. Next where he says, 'So, too, of such things . . .' (230 a 10), he shows that rest is not opposed to these mutations.

             Concerning this he makes three points. First he states his position. Secondly, where he says, 'Should there be a particular . . .' (230 a 10), he inserts a difficulty. Thirdly, where he says, 'If it is, then either . . .' (230 a 14), he proves his position.

             He says, therefore, first that in mutations which do not occur between contraries, there is no opposed state of rest. Rather that which is opposed to mutation, as rest is opposed to motion, can be called an immutation, or a non-mutation.

             734. Next where he says, 'Should there be a particular . . .' (230 a 10), he inserts a difficulty concerning this. It was said that mutation to being is contrary to mutation from being. This latter is mutation to non-being.

             That which is called non-being can be understood in two ways. First, non-being might have a subject. This subject is either being in act, as non-white is in a body, or only being in potency, as privation of substantial form is in primary matter. Or non-being might be understood as having no subject. This is absolute non-being.

             If non-being is taken in the first way, that is, as having a subject, then it can be discovered how one non-mutation is contrary to another. For it could then be said that non-mutation to being is opposed to non-mutation to non-being. For when non-being has a subject, there is nothing to prevent us from saying that that subject remains in that non-being. In other words it is not changed.

             But if non-being be taken as not having any subject, then a difficulty arises. To what non-mutation is the non-mutation or rest in being contrary? That which in no way is cannot be said to be at rest or to remain immutably permanent. And since it is necessary for some non-mutation to be contrary to non-mutation or rest in being, it becomes clear that that non-being from which generation occurs and to which corruption tends is a non-being which has a subject.

             735. Next where he says, 'If it is, then either . . .' (230 a 14), he proves what he has stated above, namely, that rest is not opposed to generation and corruption.

             If it be granted that there is rest, then one of two things follows. Either not every rest is contrary to motion, or else generation and corruption are motions. Hence it is clear that that which is opposed to generation and corruption is not called rest unless generation and corruption are motions, which was disproved above.

             736. Next where he says, '. . . we must say that it is . . .' (230 a 17), he shows how non-mutation is contrary to mutation.

             He says that the contrariety of immutation to mutation is similar to the contrariety of rest to motion. Immutation in being is contrary either to no immutation (which would be the case if non-being were to have no subject) or to non-mutation in non-being, if non-being has a subject. This is a contrariety in the way in which rest is opposed to rest. And non-mutation in being is also opposed to corruption in the way in which rest is opposed to motion.

             But non-mutation in being is not opposed to generation. For corruption recedes from the immutation or rest in being, but generation tends toward it. And rest in the terminus from which, but not rest in the terminus to which, is opposed to motion and mutation.