LECTIO FIFTEEN

             § 818. So far the Philosopher has pursued his enquiry into the principle of local movement in animals by the method of refuting unsatisfactory solutions; but now he states the positive truth on the matter: first, showing in general what that principle is; and secondly, at 'Generally then', how it varies in different subjects. The first point again divides into (a) a statement of the motive-principle in animals; and (b), at 'The motive-force will therefore', an analysis of the factors at work when this principle is in action. Again (a) subdivides into three points: (1) That there are two motive-principles; which (2) he reduces to one, at 'Now the intellectual power', while with (3) he answers an objection (at 'Since appetites . . .') already raised.

             First, then, he says that the foregoing examination makes it clear that neither the vegetative nor the sensitive part is the motive-principle, since they are found in things that do not move. So it would seem that the moving principles are two: intellect and appetency. Note, however, that he includes imagination under intellect; for it resembles intellect in that it impels to action in the absence of sense-objects.

             § 819. For in their actions many people follow the changes in their imaginations rather than rational knowledge; for instance, those who act impulsively without reflection. Besides, other animals are obviously only impelled to action through imagination, not through intellect or reason; but men through both intellect and imagination. Clearly, then, both these are motive-principles: intellect (including imagination) and appetition.

             § 820. Then at 'Now the intellectual,' he reduces the two to one; and this in three stages: (1) justifying the reduction; (2), at 'All intellect, then, is right,' using it to show the cause of a particular accidental factor in animal movements; and (3) refuting, at 'For those who divide', an early division of the powers of the soul.

             First, then, he says that the mind as a motive-principle is the mind in so far as it reasons for some purpose other than mere reasoning; in other words, it is the practical reason, which differs from the speculative by a different finality; for while the latter regards truth for its own sake and nothing else, the practical reason relates its knowledge of truth to some deed to be done.

             § 821. Now obviously every appetition is for some end beyond itself. It is absurd to say that desire is for the sake of desiring; desire is essentially a tendency to 'the other'. Moreover, an object of desire is always the practical reason's starting point; what is first desired provides the end whence its deliberations begin. If we wish to weigh a course of action we first lay down some end and then deliberate about the means, moving back, so to say, from what is to come later on to what is immediately to be done at the beginning. So he adds that the last thing that the practical reason considers is the first thing that has to be done--i.e. the starting point of the whole action. This is why it is reasonable to assert that both appetition and the practical reason are motive-principles; for the object desired certainly incites to action, and it is also what the practical reason first considers; so that the latter is said to impel to action because the starting point of its deliberations, the object desired, does so.

             § 822. And what is said of the intellect may be applied to the imagination; if it moves it does so only in virtue of an object desired: of which it contains, like the intellect, a representation.

             § 823. So it is clear that there is ultimately one mover, the object desired. For this both moves appetition and affords a starting point for the practical intellect--the two motive-principles which have been assumed.

             § 824. And it is reasonable that these two principles should be reduced to unity in the object of desire; for if both intellect and appetition are principles with respect to one and the same movement they must, as such, share the same specific nature; since a single effect implies always a single cause of precisely that one effect. Now it cannot be said that appetite is a moving principle through sharing the specific nature of intellect, but rather e converso; for intellect only moves anything in virtue of appetition. It moves by means of the will, which is a sort of appetition.

             § 825. The explanation of this (given in Book IX of the Metaphysics) is that the practical reason is essentially balanced between alternatives; nor can it initiate movement unless appetition fixes it exclusively upon one alternative. Appetition, on the other hand, can move to action independently of reason, as we see in the case of the concupiscible desire which is a sort of appetite. He mentions this desire rather than the irascible because, unlike the irascible, it has no admixture of rationality (as he shows in Book VII of the Ethics). Clearly, then, the motive-principles are reducible to the one object of appetition.

             § 826. Next at 'All intellect then', he applies what has been said to a particular accidental factor in movement or action, explaining why we go amiss in our actions. 'All intellect', he says, 'is right', by which he means that we never err about the first principles of action, about such truths as 'it is wrong to do harm to anyone', or 'injustice is never right', and so on. Those principles correspond to the equally infallible first principles of the speculative reason. But as for the consequences of these first principles, if we apprehend them aright it is because our thought is consistent with our grasp of the principles, whereas if we deviate from the truth the fault lies in our reasoning. Appetition and imagination (motive-principles likewise) may be, on the other hand, either right or wrong. Hence if we act amiss it is, in the last analysis, because we fall short of what we intellectually know; and our previous conclusion stands, that the final motive-impulse comes from the object of desire.

             § 827. Now this object is either a real good or a seeming good: it is a real good if the mind's original correct judgement is maintained; it is only a seeming good if appetite or imagination cause a deflection from that judgement. Yet not every good is desirable as a cause of action, but only the good-as-term-of-action, i.e. a good that is actually related to our actions. And precisely as such no such good is always good in the same way; for it must vary in relation to ourselves. That is why the ultimate and absolute good, regarded in its universality, does not, as such, move us to act. Clearly, then, the final motive force derives from the soul itself acting through the appetitive power.

             § 828. Then at 'For those who divide', he rejects an old division of the motive parts of the soul into the rational, irascible and concupiscible potencies. If, he says, the intention was to enumerate the potencies which are really distinct from each other, others should have been included, namely the vegetative, sensitive, intellectual, deliberative and appetitive powers. These last two are distinguished in the same way and for the same reason as, in the Ethics, Book VI, Aristotle distinguishes the ratiocinative faculty, which has to do with contingent matters, from the scientific faculty which has to do with necessary objects. All these parts of the soul differ more than the irascible and concupiscible, which are both included in the sensitive appetite. Hence that old division was incomplete.

             § 829. Next, at 'Since appetites may' he meets an objection already touched upon, namely that if desire were a motive force, nobody would be continent; the continent, by definition, do not follow their desires. But this difficulty vanishes if we consider that in man there are contrary appetites, of which the continent follow one and reject the rest. Contrariety of desires springs out of an opposition between reason and the concupiscible appetite; and this happens 'in beings possessing a time-sense', i.e. that are aware, not of the present moment only, but of past and future as well. For sometimes the mind forbids a man to indulge a desire in view of what will happen in the future if it is indulged: thus a man in a state of fever sees with his mind that he ought to abstain from drinking wine. But desire prompts one to take things for the sake of 'what is now', i.e. in the present moment. For what is here and now pleasant seems absolutely pleasant and good if it is not related to the future.

             § 830. Then at 'The motive-force' he analyses the process of the movements in question; and this in three stages. First, he shows how the factors in movement are at once many and one. Next, at 'Since there are these three', he explains how they are interrelated. Finally, at 'Now, in short . . .' he briefly defines each of the factors on which movement depends. First, then, he observes that if the moving principles are considered formally and specifically they are reducible to one, to the object of desire or appetite; for this is the absolute starting point of movement, inasmuch as, being itself unmoved, it initiates movement through the mind or the imagination. And because the secondary motive-principles only move in virtue of their share in the primary one, therefore they all as such partake of the nature of this primary one. And yet, though specifically one, they are numerically many.

             § 831. Then at 'Since there are these three', he interrelates three factors in movement: (1) the mover, (2) the organ by which it moves, and (3) the thing moved. Now the mover is twofold: an unmoved mover, and a mover that moves through being moved itself In the case of animals, the unmoved mover is some actual good influencing desire through the intellect or imagination. The mover moved is the desire itself; for whatever desires is moved inasmuch as it desires, desire itself being a certain act or movement in the sense that we give to the term 'movement' when we apply it to activities that are consequent upon actuality, such as sensing and understanding. Then the thing moved is the animal itself. And the organ by means of which desire issues into movement is a part of the body; it is the primary motor-organ; hence it has to be treated along with the activities common to body and soul (and is, in fact, examined in the De Causa Motus Animalium). But here and now we are concerned particularly with the soul.

             § 832. Next, at 'Now, in short. . .', he briefly states his view on the organ of local motion. He says that the primary organic motive-principle must be such that the movement starts and finishes in the same point, proceeding in a circle, as it were, and having a swelling out at the starting point and a concavity at the end. For the contractual movement draws the organ into concavity, while the expansive impulse, whence movement begins, follows a swelling out of the organ.

             § 833. Now, granted that this primary organ is both the starting point and term of movement, it must, as starting point, be motionless, and, as term, in movement; and both these at once. For in any movement the starting point itself does not move, all movement must proceed from the motionless,--as, for instance, while the hand is moving the arm is still, and while the arm moves the shoulder is still. However, these two factors in the organ, the motionless and the moved, though distinct in thought, are substantially and spatially inseparable.

             § 834. And that the organ is both starting point and term (and therefore both motionless and moved) is clear from the fact that all animal movements consist of impulsions and retractions. In impulsion the motive force comes from the starting point, for the impelling agent thrusts itself forward against what is impelled. But in retraction the motive force comes from the term, for the drawing power draws something back to itself Thus the first organ of local motion in animals must be at once both a starting point and a term.

             § 835. So then there must be in it something that stays still and yet initiates motion. And in this it resembles circular movement: for a body revolving in a circle is kept as a whole in the same place by the immobility of the centre and the poles. In thought it may move as a whole, but not in reality. In reality it keeps to one place. But its parts are changing their places really, and not only in thought. And so it is with the heart: it remains fixed in the same part of the body while it dilates and contracts and so gives rise to movements of impulsion and retraction. Thus it is, in a sense, both motionless and moving.

433b 27-434a 21

THE PRINCIPLES OF MOVEMENT IN LIVING BEINGS, CONTINUED

             GENERALLY, THEN, AN ANIMAL IS SELF-MOVING Inasmuch as it is appetitive, as we have said. But there is never appetition apart from imagination; and all imagination is either rational or sensitive. It is in the latter, then, that other animals also participate.§§ 836-7