Lecture 10 — The principles of movement in living beings continued

Generally, then, all animals have the power of self-movement inasmuch as they have appetite, as we have said. But there is never appetite apart from imagination; and all imagination is either rational or sensitive. It is in the latter, then, that other animals also participate.

Now, we must consider the mover within those incomplete animals in which there exists no sense but touch, and whether or not they have imagination and desire. For pain and pleasure do seem to be present in them; and if these, then, necessarily, desire as well. But how can there be imagination in them? It may be that as they are moved indeterminately, so these things are present indeed in them, but only indeterminately.

Sensitive imagination, then, exists also in other animals, as we have said, but the deliberative is only in rational beings. For to deliberate whether to do this or that is the work of reason, and it is necessary to measure by just one thing, for it imitates the better, so it can form several phantasms into a unity. And this is why the animals are thought not to have opinion, since they lack that which derives from syllogism, but these ones do have that. For this reason, the appetite is without deliberation.

Appetite, however, sometimes overcomes and moves deliberation. But sometimes it moves itself, like the sphere, an appetite moving an appetite, when this happens in self-control. But by nature what is above is always more fundamental and moves the lower such that it is moved with three motions.

Now, the scientific power does not cause movement, but remains at rest. But this judgment and reason is of the universal, while the other is of the particular—for the former says that such a one should do such a thing, while the latter says that this is such an action and I am such a man.

Therefore right away the latter opinion moves one, not the universal—or both together; rather, the one as being more at rest, the other less so.

836. Generally then, all animals (433b27). The Philosopher now passes from a general consideration of the principle of local movement in common and in itself to viewing it in relation to different genera of animals. And he does three things here.

First, he states what is common to all animals that move;

second, at now, we must consider (433b31; [838]), he discusses the motive-principle of incomplete animals;

and third, at sensitive imagination (434a5; [840]), he discusses the principle of motion of the most complete animal, man, in whom this principle exists in a unique way.

First, then, he observes that all animals, inasmuch as they have appetite, have the power of self-movement; for appetite is the proper cause of movement. But there is never appetite apart from imagination, either rational or sensitive; and while other animals participate in the sensitive imagination, rational imagination is in man alone.

837. Note, however, that, just as Aristotle has included imagination under “intellect,” so now he extends “imagination” to the intellect, following the account of the term itself. (Lect. 9, nn. 818–19.) For imagination is a sort of appearance; and something is apparent both according to sense and according to reason. Besides, imagination, like reason or intellect, has its own activity in the absence of exterior sense-objects.

838. Then, at now, we must consider (433b31), he points to the principle of motion in the incomplete animals (for he calls “incomplete” the animals in which there exists no sense but touch). We must consider, he says, what it is that moves these animals: is it imagination and desire or not? They seem indeed to have desires, for they seem to feel pleasure and pain: they shrink back when touched by things that harm them but open out and extend themselves towards things that suit them, which cannot happen to them without pain and pleasure. And if these, then, are present in them, it is necessary that desire is present in them. For desire follows from a sense of pleasure. But pleasure is not without imagination.

839. So, then, how is imagination in them? He answers that, just as they are moved, so too is imagination and desire present in these animals. But they do not move in a determinate way, as though intending to arrive at any determinate place, as do the animals that move from one place to another, which latter imagine something at a distance, and so desire it and move toward it. But such incomplete animals do not imagine anything at a distance, since they imagine only at the presence of a sense-object. Rather, when they are hurt, they imagine what is harmful and draw back, and when they feel pleasure, they reach out to it and cling to it. And in this way both imagination and desire in them are indeterminate, inasmuch as they imagine and desire something as suitable, but not as this or that, or as here or there; rather, they have a confused imagination and desire.

840. Next, at sensitive imagination (434a5), he points out the motive-principle in man; and this, in three stages.

First, he shows how this moving principle is the deliberative reason;

next, at appetite, however, sometimes overcomes (434a12; [843]), how it is sometimes overcome by desire;

and third, at now, the scientific power (434a16; [845]), he show of what reason he is speaking here.

First, then, he says that while sensitive imagination exists also in other animals, as is clear from what he said above, imagination based on deliberation is only in rational animals; for to consider whether this or that should be done, which is to deliberate, is the work of reason. (Bk. 2, lect. 30, n. 657.)

841. And in such consideration it is necessary to take some sort of rule or end, or something like this, by which to measure what most needs to be done. Clearly, a man will imitate, that is, desire, that which is greater in goodness (that is, what is better); moreover, we always judge the better by a certain measure. We need, therefore, to receive a certain measure in deliberating what one should do. And this is the middle term based on which practical reason syllogizes about what one should choose. It follows that reason, deliberating, can form several phantasms into a unity—three, to be precise; for one object is preferred to another, and a third is the measure whereby one prefers it.

842. And this is why animals have no opinions, though they have imagination. For they cannot use a syllogism, whereby they might prefer one thing to another. But the deliberation of reason has that, that is, imagination, otherwise it would not make one thing from many phantasms. And this is why the lower appetite, which follows from imagination, is without deliberation, rather, it is moved into desire or repulsion without deliberation because it follows the sensitive imagination.

843. Next, at appetite, however, sometimes (434a12), he explains how the deliberation of reason is overcome by the lower appetite. And he says that sometimes a lower appetite, which occurs without deliberation, overcomes deliberation and draws a man away from that which he deliberated. But sometimes, conversely, an appetite moves an appetite, that is, the higher appetite, which belongs to the deliberating reason, moves the appetite that belongs to sensible imagination, like in heavenly bodies the higher sphere moves the lower. This happens when someone is self-controlled; for it belongs to the self-controlled to overcome the impulse of passions through the deliberation of reason.

844. And such is the natural order that the higher appetite moves the lower. For even in the heavenly bodies the higher sphere naturally is more fundamental and moves the lower, and does so in such a way that the lower is moved with three local motions.

For example, the sphere of Saturn is moved with the daily motion, which is the motion about the poles of the universe; and with a contrary motion, which is about the poles of the zodiac; and besides this, with its own proper motion.

Likewise, the lower appetite, even if it retains something of its own proper movement, is nevertheless in the natural order moved by the motion of a higher appetite and also by the movement of rational deliberation. But if the converse takes place, and the higher appetite is in fact moved by the lower, this is outside the natural order; and hence, this constitutes a flaw in moral conduct, just as deformed births are flaws in nature.

845. Then, at now, the scientific power (434a16), he explains which reason it is that moves. First, note that the speculative reason, here called “scientific,” does not cause movement; rather, this is at rest, since it says nothing about what should be imitated or fled, as we have seen. (Lect. 8, n. 813.) Practical reason, however, is in a certain way of the universal, but in a certain way of the particular. It is of the universal as what says that such a one should do such a thing, for example, that a child should honor his parent. But the reason is of the particular when it says that this is such an action and I am such a man, for example, that I, a son, ought now to show my parent this honor.

846. Therefore right away the latter opinion moves one, not the opinion that is universal—or if both together move one, rather, that which is universal moves one as a first cause and as at rest, whereas the particular opinion moves one as a proximate cause and as applied to the movement. For acts and movements are in particulars, and if any movement is actually to take place, the universal opinion must be applied to particulars. On account of this, the commission of a sinful action happens when one’s opinion in the particular thing to be done is corrupted by some pleasure or some other passion that, nevertheless, does not corrupt the universal opinion.