LESSON 7

How the First Mover Causes Motion

  Chapter 7: 1072a 26-1072b 14

             1067. Now the first mover causes motion as something intelligible and something appetible; for these alone cause motion without being moved. And what is first in the class of the appetible and in that of the intelligible is the same; for it is the apparent good which is the object of concupiscible appetite, and the real good which is the primary object of will. For we desire a thing because it seems good rather than consider it good because we desire it; for understanding is the principle of desire. And the intellect is moved by an intelligible object.

             1068. And one of the two columns of opposites (60) is the intelligible in itself; and in this class primary substance is first, and in substance that which is simple and exists actually. However, one and simple are not the same; for one signifies a measure (432; 825), and simple signifies a state.

             1069. But that which is good and that which is desirable in itself are in the same column of opposites; and that which is first in each class is always best, or analogous to the best. That the final cause belongs to the class of immovable things is shown by a process of division; for the final cause of a thing is either that which exists or that which does not.

             1070. And it causes motion as something loved, whereas by that which is [first] moved other things are moved. Therefore, if a thing is moved, it is possible for it to be other than it is. Hence, local motion, which is the primary kind of motion, is also the actuality of that which is [first] moved; and in this respect the thing first moved can differ in place though not in substance. But since there is something which moves yet is itself immovable and exists actually, this can in no way be other than it is. For the primary kind of change is local motion, and of local motion the first is circular motion; and this is the motion which the first mover causes. Hence the first mover necessarily exists; and insofar as it is necessary it is good, and thus is a principle. For necessary has all of these meanings: that which seems to be done by force; that without which something does not fare well; and that which cannot be other than it is, but is absolutely necessary (416-22). It is on such a principle, then, that the heavens and the natural world depend.

COMMENTARY

             2519. After having shown that there is an eternal, immaterial, immovable substance whose essence is actuality, the Philosopher now proceeds to investigate the attributes of this substance. In treating this he does three things. First (1061:C 2519), he considers the perfection of this substance. Second (1078:C 2553), he asks whether it is one or many ("We must not"). Third (1089:C 2600), he considers its operation ("The things which pertain").

             In regard to the first he does two things. First, he shows the perfection of this substance. Second (1076:C 2548), he proves that it is incorporeal ("And it has been shown").

             In regard to the first he does two things. First, he shows its perfection. Second (1075:C 2545), he rejects a contrary opinion ("And all those").

             In regard to the first he does two things. First, he explains how the unmoved mover causes motion; and second (1068:C 2523), he infers from this what is comprised in its perfection ("And one of the two").

             He accordingly says, first (1067), that, since it has been shown that the first mover is unmoved, it must cause motion in the way in which the desirable and the intelligible do; for only these, the desirable and the intelligible, are found to cause motion without being moved.

             2520. He proves this as follows. Motion is twofold: natural and voluntary, or according to appetite. Now that which causes motion by means of natural motion necessarily undergoes motion, since a natural mover is one that begets and alters things. For both heavy and light bodies are moved locally directly by their begetter. But that which begets and alters things directly must exist in different states. Hence it has also been pointed out above (1065:C 2510) that the cause of generation and destruction acts in different ways. Now in the case of voluntary and appetitive motion, will and appetite have the character of moved movers, as is evident in Book III of The Soul. Hence it remains that only that which causes motion as something appetible is an unmoved mover.

             2521. Now it is said that the first mover causes motion as something appetible because the motion of the heavens has this mover as its end or goal, for this motion is caused by some proximate mover which moves on account of the first unmoved mover in order that it may be assimilated in its causality to the first mover and bring to actuality whatever is virtually contained in it. For the motion of the heavens does not have the generation and destruction of lower bodies as its end, since an end or goal is nobler than the things ordained to it. Therefore the first mover causes motion as something appetible.

             2522. But in our own case that which causes motion as a desirable good differs from that which causes motion as an intelligible good, though each causes motion as an unmoved mover. This is particularly evident in the case of an incontinent person; for according to his reason he is moved by an intelligible good, but according to his concupiscible power he is moved by something pleasant to the senses, which, while it seems to be good, is not good absolutely but only with some qualification.--However, this kind of difference cannot be found in the first intelligible and the first desirable good. But the first intelligible and the first desirable good must be the same. The reason is that a concupiscible good, which is not an intelligible good, is merely an apparent good; but the first good "must be an object of will," i.e., an object desired by intellectual appetite. For will belongs to the intellectual order and not merely to that of concupiscible appetite. And this is so because what is desired by the concupiscible power seems to be good because it is desired; for concupiscence perverts the judgment of reason insofar as something pleasant to sense seems to be good to reason. But what is desired by intellectual appetite is desired because it seems to be good in itself. For "understanding" as such, i.e., the act of intellection, which is moved in a way by an intelligible object, "is the principle of desire." Therefore it is evident that the object of concupiscible appetite is good only when it is desired through a dictate of reason. Hence it cannot be the first good, but only that which, because it is good, moves desire and is at once both appetible and intelligible.

             2523. And one of the two (1068).

             Since he has proved that the first mover is both intelligible and appetible, it now remains to show from this how perfection is found in the first mover. In regard to this he does three things. First (1068:C 2523), he shows the perfection of the first mover in itself by considering the formal character of the intelligible and the appetible; second (1070:C 2529), in relation to the first sphere ("And it causes motion"); and third (1071:C 2536), in relation to the thing that desires and understands it ("And its course of life").

             In treating the first part he does two things. First, he proves that the first mover is perfect on the ground that it is intelligible; and second (1069:C 2526), on the ground that it is appetible ("But that which is good").

             He says, first (1068), that, just as movers and things moved are related to one another, so also are intelligible things. He calls this latter relationship an intelligible column of opposites because one intelligible is the first principle for understanding another, just as one mover is also the cause of the motion of another.

             2524. Therefore, just as it has been shown (1066:C 2518) from the series of movers and things moved that the first mover is a simple substance and an actuality, in a similar fashion the same thing is found to be true from the series of intelligible things. For it is evident that substance is the first of intelligible things, because we understand accidents only by means of substance, through which they are defined; and among substances a simple intelligible substance is prior to a composite one; for simple things are included in the concept of composite things. And of the simple entities contained in the class of substance the actually intelligible are prior to the potentially intelligible; for potentiality is defined by means of actuality. It follows, then, that the first intelligible entity is a simple substance which is an actuality.

             2525. And lest he should seem to be adopting the opinion of Plato, who claimed that the first principle of things is the intelligible one-in-itself, he therefore explains the difference between being one and being simple. He says that one and simple do not signify the same thing, but one signifies a measure, as has been pointed out in Book X (825:C 1950-52), and simple signifies that state whereby something is such as not to be composed of many things.

             2526. But that which is good (1069).

             Then he proves the same point from the formal character of the appetible. He says that that which is good and that which is desirable in itself belong to the same class. For that which is prior in the class of intelligible things is also a greater good in the class of appetible things, or is something analogous to it. He says this because intelligible things are actual insofar as they exist in the intellect, whereas appetible things are actual insofar as they exist in reality; for good and evil are in things, as has been pointed out in Book VI (558:C 1240).

             2527. Hence, just as the concept of intelligible substance is prior to that of intelligible accidents, the same relationship holds for the goods which correspond proportionally to these concepts. Therefore the greatest good will be a simple substance, which is an actuality, because it is the first of intelligible things. It is evident, then, that the first mover is identical with the first intelligible and the first appetible good, which is the greatest good.

             2528. But since what is appetible and what is good have the character of an end or goal, and there does not seem to be an end in the realm of immovable things, as has been explained in the dialectical discussions in Book III (192:C 374-75), he therefore removes this difficulty. He says that the division in which the various senses of end or goal are distinguished shows that a final cause can be found in a way in the realm of immovable things. Now one thing can be the goal of another in two ways: first, as something having prior existence, as the center of the world is said to be a goal which is prior to the motion of heavy bodies; and nothing prevents a goal of this kind from existing in the realm of immovable things. For a thing can tend by its motion to participate in some degree in something immovable; and the first mover can be a goal in this way. Second, one thing is said to be the goal of another, not as something that exists actually, but only as existing in the intention of the agent by whose activity it is produced, as health is the goal of the activity of the medical art. An end or goal of this kind does not exist in the realm of immovable things.

             2529. And it causes motion (1070).

             He now relates the first unmoved mover to the first sphere. He says that, since the first unmoved mover causes motion as something loved, there must be something which is first moved by it, through which it moves other things. This is the first heaven. Therefore, since we suppose motion to be eternal, the first sphere must be moved eternally, and it in turn must move other things. And it is better to speak of it as something loved rather than as something desired, since there is desire only of something that is not yet possessed, but there is love even of something that is possessed.

             2530. And if it must be moved eternally, it must be incapable of being other than it is but must always remain substantially the same. Hence the primary kind of motion, by which "the first sphere" is moved, necessarily "is local motion," i.e., motion as regards place; because that which is moved "according to the other kinds of motion," i.e., generation and destruction, increase and decrease, and alteration, must differ as regards something intrinsic, namely, substance, quantity or quality. But that which is moved with local motion differs as regards place, which is extrinsic to the thing in place, but not as regards substance or any intrinsic disposition of substance.

             2531. Therefore, since the first sphere differs as regards place but not as regards substance, the first mover, which is immovable and always actual, can in no way be other than it is, because it cannot be moved. For if it were moved, it would be moved especially with the primary kind of motion, which is local motion, of which the first type is circular. But it is not moved with this motion, since it moves other things with this motion. For the first mover is not moved with that kind of motion by which it imparts motion, just as the first cause of alteration is not itself altered. Hence it is not moved circularly, and so cannot be moved in any way. Therefore it cannot be other than it is; and thus it follows that the primary kind of motion exists in that which is moved of necessity; for that is necessary which cannot not be. But it is not necessary in the sense in which things forced are necessary, but its necessity consists in its good state. And the thing which moves it is a principle of motion as an object of desire, or a goal.

             2532. That its necessity is such becomes evident from the different meanings of the term necessary, for it is used in three senses. First it means that which happens by force, i.e., what cannot fail to happen because of the power exerted by the thing applying force. Second, it means that without which a thing does not fare well--either that without which a goal cannot be attained at all (as food is necessary for the life of an animal), or that without which something is not in a perfect state (as a horse is necessary for a journey in the sense that it is not easy to make a journey without one). Third, it means that which cannot be other than it is, but is necessary absolutely and essentially.

             2533. Therefore, when it is said that an orb is moved of necessity, such necessity cannot be called necessity of force; for in imperishable things there is not found anything that is outside their nature, but in the case of things which are forced what occurs is not natural. Similarly such necessity cannot be absolute necessity, because the first thing which is moved moves itself, as is proved in Book VIII of the Physics, and what moves itself has within itself the power to move or not move. It follows, then, that the necessity of the first motion is necessity from the end, inasmuch as there cannot be a fitting order to the end unless such motion is eternal.

             2534. Hence it is on this principle, i.e., the first mover viewed as an end, that the heavens depend both for the eternality of their substance and the eternality of their motion. Consequently the whole of nature depends on such a principle, because all natural things depend on the heavens and on such motion as they possess.

             2535. It should also be noted that Aristotle says here that the necessity of the first motion is not absolute necessity but necessity from the end, and the end is the principle which he later calls God inasmuch as things are assimilated to God through motion. Now assimilation to a being that wills and understands (as he shows God to be) is in the line of will and understanding, just as things made by art are assimilated to the artist inasmuch as his will is fulfilled in them. This being so, it follows that the necessity of the first motion is totally subject to the will of God.