LECTIO TWELVE

             § 765. Here the Philosopher turns to consider the intellect as compared with the senses; first explaining the kind of movement that sensation involves; and secondly, showing how this movement resembles that of the intellect. On the former point he observes that the sense-object appears to play an active part in sensation, in so far as sensitivity as a whole is, to start with, in potency. For the sense-object and the sense-faculty are not mutually exclusive things, as though, when one acted on the other it had to transform and alter the latter by destroying something within it. In fact, all that the object does to the faculty is to actualise it; so he adds that sensitivity is not passive to the change-producing activity of the sense-object in the ordinary sense of the terms 'passivity' and 'change', which generally connote the substitution of one of two mutually exclusive qualities for the other.

             § 766. Since, as he shows in the Physics, changes of bodies are of this latter kind, it is clear that if we call sensation a change we mean a different sort of change. Movement from one mutually exclusive quality to another is the actuality of a thing in potency; for while the thing is losing one quality, and so long as it still has not the other, its movement is still incomplete and it is in potency. And because the potential as such is imperfect, this kind of movement is an actuality of the imperfect; whereas the kind we are concerned with here is an actuality of what is perfect, -the response of a sense-faculty already actualised by its object. Only the senses in act can have sensations. So their movement is quite different from physical movement. It is this movement also which, together with understanding and willing, is properly called an 'operation' and this also is what Plato referred to when he said that the soul moves itself through knowing and loving itself.

             § 767. Next, at 'Sensation therefore', he likens the intellect's movement to that of the senses;--first showing how the senses move, and then, at 'Imaginative phantasms', how a similar movement takes place in the intellect. As regards the former point he says that, since the sensible object actualises our sensitivity without any accompanying passion (properly so called) or alteration, and the like also happens in intellection, as we have already seen, therefore sensation resembles the act of the intellect--that is to say, mere sensation, with its sensuous apprehension and judgement, resembles mere intellection, with its intellectual apprehension and judgement. Pure sensuous apprehension and discernment resemble intellectual understanding and discernment. But when the senses affirm (so to say) pleasure or pain in their act of perceiving, then appetite comes into play, i.e. a desire or avoidance of the object perceived. And note the phrase 'so to say'; for properly speaking affirmation and denial are acts of the intellect; but something like them occurs when pleasure or pain is experienced sensuously.

             § 768. And to show what pleasure and pain are, he observes further that the act of perceiving pleasure and pain takes place in the 'sensitive mean'; that is to say, it is the act of a certain midway faculty of sense--so called because the common sense is a sort of medium between the particular senses, like the centre of a circle in relation to lines drawn from the circumference. But not every act of the sensitive part is a sense of pleasure or pain. This perception relates precisely to the good and the bad as such. For the good of the senses--i.e. what suits them--gives pleasure; while what is bad, i.e. repugnant and harmful to them, causes pain. And pain and pleasure are followed, respectively, by avoidance and appetite (or desire); and these are a sort of activity.

             § 769. Thus the movement from sense-object to sense passes through three stages, as it were. There is first an awareness of the object as being in harmony or out of harmony with the sense: then a feeling of pleasure or pain; and then desire or avoidance. And although desiring, avoiding and mere sensing are different acts, still they are all acts of identically the same subject, though they can be distinguished in thought. This is what he means by adding that the 'desiring and avoiding'--i.e. that part of the soul which desires or avoids, is not divided in being nor distinct from the sensitivity; although in 'essence' they 'differ', i.e. are represented by different concepts. He says this against Plato in particular, who maintained that desire and sensation had distinct organs in different parts of the body.

             § 770. Next, at 'Imaginative phantasms', he compares the mind's movement to the process of sense-knowledge as he has described it. And he does two things here: he shows how the mind is related (a) to sense-objects, and (b) at 'The mind understands by abstraction' to objects beyond the range of sense. (a) divides into (i) an explanation of the way the mind is related to sense-objects in practical activity; and (ii) at 'And generally in practical affairs', a comparison of the practical and speculative intellects. And with regard to the former point, he first states and then, at 'This is comparable to the way', illustrates the resemblance between the mind's activity and that of the senses.

             First, then, he observes that phantasms are to the intellectual part of the soul as sense-objects to the senses; as these last are affected by their objects, so is the intellect by phantasms. And as sensation of the pleasant or painful is succeeded by desire or avoidance, so also the intellect, when it affirms or desires goodness or badness in an object it apprehends, tends either towards or away from that object.

             § 771. But note that Aristotle's use of terms here suggests a twofold difference between intellect and senses. For in the first place, when the senses apprehend their good and evil, this awareness is not immediately succeeded by pursuit or avoidance, but by pleasure and pain,--after which the sensing subject pursues or withdraws. The reason is that as the senses are not aware of goodness in general, so sense-appetition is not swayed by the good or the bad in general, but only by this or that particular good, pleasant to sense, or, by this or that particular evil, unpleasant to sense. The soul's intellectual part, on the contrary, is aware of goodness and badness in general; hence its appetition at once and immediately responds to this apprehension.

             § 772. The other difference appears in Aristotle's observing, unconditionally, that the intellect affirms or denies, whereas of the senses he only says that they affirm 'so to say'. The reason for this has already been given. And from what has been said he draws the further conclusion that if intellect is related to phantasms as the senses to their object, then just as the senses cannot sense without an object, so the soul cannot understand without phantasms.

             § 773. Then, where he says 'This is comparable', he explains the resemblance still further: (a) as regards the likeness between phantasms and sense-objects in relation to the intellectual soul; and (b)--at 'The intellectual faculty therefore' -as regards the avoidance or pursuit that follows the affirmation or denial of goodness or badness.

             First, then, he remarks that colour-affected air itself modifies the pupil of the eye in a particular way, i.e. it imprints on it a likeness of some colour, and that then the pupil, so modified, acts upon the common sense. Similarly our hearing, itself affected by the air, acts upon the common sense. And though there are several exterior senses, their reactions all come back to one point, which is a certain common medium between all the senses, like a centre upon which lines from a circumference all converge.

             § 774. And while this mid-point is a unity as a subject, its 'essence' is manifold, that is to say, the idea of it varies according as we relate it to the different senses. It is the faculty by which the soul sees the difference between the sweet and the hot, as we saw when we were considering it in itself; and now, relating it to the intellect, we may say that, as all sensible objects find a common terminus in the common sense, so do all phantasms in the intellect. And as in the one case many objects were said to be judged by a single principle, so in the other case also in a like proportion. Again, as to the number of objects judged: the intellect is related to both objects whose distinction it perceives as 'they' to one another, i.e. as the single common sense to the different sensibles whose differences it discerns.

             § 775. It makes no difference whether we speak of the non-homogeneous, i.e. of different sensibles differing in genus, for instance of white which is a colour, and sweet which is a savour; or of contrary qualities of the same genus, like black and white. For the common sense discriminates between both kinds of difference.

             § 776. For white, then, let us put A, and for black, B; so that, as A is to B, so is C to D; the latter standing for the phantasms of white and black respectively. Then, varying the proportions, A is to C as B to D: i.e., white is to the phantasm of white as black to the phantasm of black; and as the intellect is to C and D, so is the sense in question to A and B. If therefore C and D, the phantasms of white and black, are related to a unity in so far as they are judged by one intellect, they resemble in this A and B, namely white and black, which are judged by one sense; so that, just as the sense which discriminates these two is in itself one, but twofold in thought, so also is the intellect. And the same reasoning is valid if we take non-homogeneous objects--taking, for instance, A for sweet and B for white.

             § 777. Next, at 'The intellectual faculty', he explains what he said above, that in affirming or denying good or evil the mind either avoids or pursues; and so concludes that the intellectual part of the soul understands intelligible forms abstracted from phantasms. And just as, when sensible objects are actually present, the mind is impressed by whatever is congenial or abhorrent in them, so too, in the absence of such objects externally, the mind is induced to desire them or fly from them by their representations present in the imagination.

             § 778. And he gives examples. First, of the process that is started by sense-objects actually present--as when a man sees something fearful, for instance the confusion caused by a fire in a city; seeing the flames leaping he knows 'in general'--i.e. by some common faculty of judging, or perhaps according to what commonly happens--that a conflict is raging; and thus the mind is moved to pursue or flee by objects present exteriorly. But sometimes phantasms or ideas presented inwardly cause the soul to deliberate about things future or present, reckoning them to be desirable or horrible,--as though they were actually seen here and now.

             § 779. Next at 'And generally', he compares speculative with practical knowledge. Truth and falsehood, he says, i.e. true and false knowing, both in the sphere of action (the practical intellect) and outside that sphere (the speculative intellect), belong to the same category, whether good or evil. This can be taken in two ways: (1) That the thing understood, either speculatively or practically, may be either good or bad, and that it remains such from the point of view of either mode of understanding; or (2) that the knowing itself is, if true, a good for the intellect, whether it be speculative or practical; whereas if false, it is an evil for the intellect, again in both cases.

             § 780. Thus he is not reducing truth and falsehood to a common genus with good and evil, but truth and falsehood in action to a common genus with truth and falsehood in speculation. This is clear from his distinguishing 'in-action' and 'not-in-action' as 'absolute' and 'relative'. For the speculative intellect considers a thing as true or false universally or 'absolutely', whereas the practical intellect relates its apprehensions to particular things to be done; for doing is always in the particular.

             § 781. Then, at 'The mind understands', having already said that there is no act of the intellect without a phantasm, and that phantasms derive from sensation, the Philosopher begins to explain how we understand things that are outside the range of sensation. Here he proceeds in two stages: (1) he explains how we understand mathematical objects abstracted from sensible matter; and (2) he enquires whether we understand anything that is immaterial in being at 'Whether it is possible'. As regards the first point, note that of things joined in reality the mind may think, and think truly, of one without the other, provided that the concept of the one is not included in that of the other. If Socrates is both white and musical his whiteness can be understood without regard to his musical character; but I cannot understand 'man' if I do not understand 'animal', for the concept of man includes animal. Thus it is possible to distinguish mentally things conjoined in reality, and yet not fall into error.

             § 782. But if the conjoined things were understood as separate things the mind would err,--as, to take our former example, if it judged that the musical person was not white. Certain aspects, however, of sense-objects the mind simply considers in separation or distinctly, without judging them to exist separately. This is what he means by saying that what the mind understands by abstraction (even mathematical objects) it understands in the same way as, e.g., a snub-nose; understanding it precisely as a snub-nose, yet not in separation from sensible matter; for sensible matter, the nose, is included in the definition of a snub-nose.

             § 783. When, however, the mind understands actually anything precisely as curved, it abstracts from flesh; not that it judges the curved thing to be not flesh, but it understands 'curved' without regard to flesh; because flesh does not enter into the definition of a curve. And it is thus that we understand all mathematical objects,--as though they were separated from sensible matter, whilst in reality they are not so.

             § 784. But we do not so understand physical things; for in their definition (unlike mathematical objects) sensible matter is included. Yet in understanding them we still abstract a universal from particulars, in so far as the specific nature is understood apart from the individuating principles; for these do not enter into the definition. And the mind in act is its object; for precisely in the degree that the object is or is not material, it is or is not perceived by the mind. And just because Plato overlooked this process of abstraction he was forced to conceive of mathematical objects and specific natures as existing in separation from matter; whereas Aristotle was able to explain that process by the agent intellect.

             § 785. Next, at 'Whether it is possible', he puts a question about things that exist immaterially: whether, that is, our intellect, though conjoined with spatial magnitude (i.e. the body), can understand 'anything separated', i.e. any substance separated from matter. He undertakes to pursue this enquiry later,--not at present, because it is not yet evident that any such substances exist nor, if they do, what sort of thing they are. It is a problem for metaphysics. In fact, we do not know Aristotle's solution of this problem, for we have not the whole of his Metaphysics; either because it is not yet all translated, or possibly because he died before he could complete it.

             § 786. We should note, however, that when he speaks of the intellect here as not 'separated' from the body he refers to the fact that it is one of the powers of the soul, which is the actuality of the body; whereas speaking, at an earlier stage, of the intellect as 'separated' he was referring to its non-organic mode of activity.

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