LECTIO FOUR

             § 615. After showing that to perceive the acts of the particular senses, and to discriminate between their various objects, are activities not beyond the range of sensitivity as a whole, the Philosopher now addresses himself to the question whether rational judgement and understanding are beyond its range. And he does two things here: first, he proves that rational judgement and understanding are not activities of sense, which is the same as to show that sense and intellect are distinct faculties; secondly, at 'For imagination is other etc.', he shows that the image-forming faculty, which is a kind of sense, is other than the power to form opinions, which pertains to reason. The former argument subdivides into (1) a statement of the theory of the identity of sense and intellect, and (2) a refutation of this theory. To the statement itself he adds an explanation of the origin of this theory, and also some remarks of certain philosophers, which seemed relevant.

             § 616. First, then, he says that as the early philosophers defined the soul especially in terms of local motion and knowledge--which includes rational discernment and sensation--it would seem to have been their view that understanding and judging were the same sort of activity as sensing; for in both there is discernment and knowledge.

             § 617. Next, where he says 'The early philosophers', he shows that this is more than a mere inference from their general teaching, and that they explicitly taught that sensation and rational understanding were identically the same. But in order to understand the words which he quotes here of these philosophers, and their relevance to the present argument, we have to consider that no body can act directly upon what is purely incorporeal. Now the sense-faculties are in part corporeal, because of the bodily organs in which they exist. Therefore they are subject to the influence of the heavenly bodies,--though, even so, only indirectly, for neither the soul itself nor any of its powers is directly subject to the action of corporeal matter. Consequently, the imagination and sense-appetite are modified in various ways by the influence of the heavenly bodies. Brute animals are generally governed by this influence, since they are led entirely by their senses. Hence to suppose that heavenly bodies act directly upon the intellect and will is to admit that these faculties are corporeal. And this is what some of the early philosophers seem to have said.

             § 618. Empedocles, for instance, said that in man, no less than in other animals, the 'will is increased', i.e. prompted to act, 'in the present moment', i.e. according to its time-context; which itself depends on the disposition of the stars. It is the present moment that 'always affords them', i.e. to men and the other animals 'new objects of knowledge'; for all the animals, men included, envisage things differently at different times.

             § 619. To the same effect Homer speaks of the mind of mortal man being 'such as the father of gods and men' (i.e. the sun) 'brings into light'. He calls the sun the 'father of men' because of the part it plays in human procreation; for man is born from man and the sun. And the sun he calls the 'father of gods', either following the old view that made gods of the other stars which, the astronomers tell us, are governed somehow by the sun, or following the view that certain men are divine because generated by solar influence. And the sun is, of course, strongest in the daytime while it is visible and is moving across the upper hemisphere; hence the name of 'day-planet' given it by astronomers. So what Homer is saying is that the sun is the cause of understanding in men, and that their knowledge of things varies with the movement, situation and appearance of the sun.

             § 620. In point of fact Aristotle quotes only the beginning of Homer's line; neither the Greek text nor the Arabic gives us the rest of it. Aristotle relies on his readers remembering the whole of it from a part, as when one quotes the first words of a well-known verse of any author. But Boethius cites the whole of Homer's line, for the sake of his Latin readers who were not familiar with that poet.

             § 621. What has been said, then, makes it quite clear that if the stars do have a direct influence on the intellect and will, then there is no difference between the intellect and the senses. There is no difficulty, however, about admitting an indirect stellar influence upon intellect and will, in so far as these faculties act in conjunction with the faculties of sense. Thus any injury to the bodily organ of the imagination will impede the intellect; and the will is incited towards choosing or not choosing by sensuous desire. But since the will is never drawn of necessity, but remains free to follow or not the promptings of desire, human actions are never completely determined by astral influences.

             § 622. Next, he states the reason why this opinion arose. If you take away that by which things differ, they are left the same; and if rationality is removed from man he is left simply an animal. Now the difference between intellectual and sensuous cognition is that the latter is corporeal. Sensation cannot occur apart from the act of a bodily organ, whereas understanding, as we shall prove later, does not take place by means of such an organ. But to the early philosophers understanding seemed a corporeal action like sensation; hence they supposed that intellect and sense were the same.

             § 623. And how they thought of both activities as corporeal he next explains, saying that they maintained that the acts of discernment in both intellect and sensation arose from the presence of a likeness of an object (as it was said in Book I) in the knowing subject; and they thought this likeness was essentially corporeal, so that earth was known by earth and water by water, and so on with other objects. And consequently, sensing and understanding were both conceived of as functions of corporeal nature, and therefore as fundamentally the same.

             § 624. He goes on now, at 'But they ought', to criticise this opinion, first with regard to the premiss on which it depends, and then at 'therefore it is evident', directly in itself. So he remarks, first, that the philosophers who explained knowledge by the presence of a likeness should have also given some explanation of error; for error seems to be even more natural to animals, as they actually are, than knowledge. For experience proves that people easily deceive and delude themselves, whilst to come to true knowledge they need to be taught by others. Again, the soul is involved in error for a longer time than it spends in knowing truth, for to acquire this knowledge even a long course of study hardly suffices. (Now this argument is indeed valid against those early philosophers who regarded knowledge as natural to the soul in the sense that the soul, being constituted of the first principles of things, knew all that could be known, and knew it actually, not merely in potency.)

             § 625. But Aristotle's objection might be answered in two ways. One might say that since the early thinkers did not admit the existence of error (their view being, as we have seen, that all that seemed to be true was true) they did not need to explain error.

             § 626. Secondly, it might be answered that to explain knowledge as a contact of the soul with what is like itself is implicitly to explain error as the soul's contact with what is unlike itself. Hence, from the fact that the early thinkers did not explicitly render an account of error, he infers that either they identified truth with appearances, or that they held that the soul went astray into error by touching things unlike itself; since to touch the unlike seems the opposite of knowing the like.

             § 627. The first alternative is refuted in Book IV of the Metaphysics.

             § 628. So he proceeds to examine the second alternative, at 'It would appear'. The like and the unlike are obviously contraries. But in knowledge and in error the relation to either of two contraries is the same: if you know one, you know the other; if you err about one, you err about the other. Hence he says that knowledge and error are apparently the same with respect to contraries. It follows that touching a like thing cannot cause true knowledge if touching an unlike thing causes error; for in that case one would know one of a pair of opposites and be mistaken about the other.

             § 629. Then, at 'Now it should be evident', he attacks the theory in question directly, and shows that neither rational judgement nor understanding is the same as sensing; they belong to intellectual knowledge. Now the intellect as judging is said to have wisdom, whilst as apprehending it is said to understand. Showing therefore that rational judgement and sensation differ, he argues thus: sensation belongs to all animals, but wisdom is found in only a few; therefore they differ. And he allows wise judgement to 'a few animals', and not exclusively to man, because even certain brute animals have a sort of prudence or wisdom, in that they instinctively form correct judgements on what they need to do.

             § 630. Secondly, at 'Nor again', he shows the difference between understanding and sensation; and this in two ways; the first being as follows. Understanding may be 'correct' or 'incorrect'. 'Correct' understanding bears either upon speculative and necessary truths, and then it is called scientific; or upon a right ordering of practical action in the sphere of the contingent, and then it is part of prudence; or upon one of two alternatives, but without deciding finally in favour of this one, and while still admitting that the other might be the truth; in which case it forms a reasonable opinion. 'Incorrect' understanding is in each case the ' opposite of correct understanding; it results in spurious science or imprudent decisions or foolish opinions. Sensation, on the other hand, can only be 'correct', for the senses are infallible with respect to their proper objects. Therefore sensation and understanding are different.

             § 631. And since it might be objected that 'correct' understanding, at least, is the same as sensation, he adds that sensation is found in 'all animals' whilst understanding is found only in rational animals, that is, in men. For it is proper to man to come to an understanding of intelligible truth by way of rational enquiry; whereas the immaterial substances, which are in a higher degree intellectual, apprehend truth immediately without having to reason about it. Therefore 'correct' understanding is not the same as sensation.

             § 632. Next, when he says 'For imagination', he shows the difference between opinion, which is of the intellect, and imagining, which is of the senses. And here he does two things: first, he shows that imagining is not opinion; then he studies the nature of imagining, at 'Concerning understanding'. The former subdivides into three parts. First he states his aim, saying that another way to grasp the difference between sense and intellect is to consider that imagining differs from both, yet presupposes sensation (as will be shown later), and itself is presupposed by opinion. For it seems that, as imagining is to the senses, so is opinion to the intellect. When we sense any sensible object we affirm that it is such and such, but when we imagine anything we make no such affirmation, we merely state that such and such seems or appears to us. The word 'imagining' itself is taken from seeing or appearing. Similarly, when we understand an intelligible object we affirm that it is such and such; but when we form opinions, we say that such and such seems or appears to us. For, as understanding depends upon sensing, so opinion depends on imagining.

             § 633. In the second place, at 'It is evident', he proves by two arguments the difference between opinion and imagination. The first is this. Images can arise in us at will, for it is in our power to make things appear, as it were, before our eyes--golden mountains, for instance, or anything else we please, as people do when they recall past experiences and form them at will into imaginary pictures. But we are not free to form opinions as we please; one cannot form an opinion without resting it on some reason, true or false. Therefore opinion is not the same as imagination.

             § 634. The second argument at 'Further, when' is this. Opinion has an immediate effect on our affective nature; so soon as we opine that anything is disagreeable or frightening we feel sad or frightened. So also if anything is thought of as encouraging or promising, we at once feel hopeful or glad. But it is not so with imagining; for so long as anything appears merely imaginatively to us, it is as if we were merely looking at pictures of frightening or encouraging objects. Therefore opinion differs from imagining.

             § 635. Now the cause of this difference is that our affective nature is not impressed or swayed by the mere vision of things brought about by imagining; but only by things regarded as good or evil, useful or harmful; and this, in man, presupposes opinion with its positive or negative judgements as to the evil and terrible or the desirable and encouraging. Mere imagining passes no judgement on things. In brute animals, however, the affective power is swayed by natural instinct; which plays the same part in them as opinion in man.

             § 636. Thirdly, at 'There are, besides', he remarks that of the many forms of intellectual judgement, such as science, prudence and opinion, with their contraries, he does not intend to treat here. They are dealt with elsewhere, in the Ethics, Book VI.

427b 27-428b 9

IMAGINATION

WHAT IT IS NOT

             CONCERNING UNDERSTANDING, SINCE IT IS ONE thing and sensation another, while imagination seems to differ from both of these and from opinion also, let us settle first what imagination is, and then speak of the other matter [opinion].§ 637

             If, then, imagination is that by which we say that some phantasm arises within us, it follows (if we are not speaking metaphorically) that it is one of the faculties or dispositions in virtue of which we perceive and pronounce either falsely or truly. Such faculties are sensation, opinion, knowledge, understanding.§§ 638-40.

             That it is not sensation is evident. For sensation is either in potency or in act: the faculty of sight, or the actual seeing. But appearances occur when neither of these is present; as when we dream.§ 641

             Further, sensation is always to be found, in potency in all animals that are not defective. Not so imagination. § 642

             But if they were the same in act, it would happen that imagination was present in all animals. But this apparently is not so--e.g. in the ant, the bee, the worm.§§ 643-4

             Again, sensations are always true: but many phantasms are false.§ 645

             Again, we do not say, when we are functioning accurately with regard to sense-objects: 'that seems to us a man'; we say this rather when our sensation is indistinct; in which case it may be true or false.§ 646

             And, as we said before, such appearances come to men in their sleep. § 647

             And it is certainly not one of the qualities which are always truthful, such as knowledge or understanding: for imagination can be true or false. § 648

             It remains therefore to consider whether it is opinion. For opinion can be either true or false. But belief follows immediately on opinion, for one never finds a man not believing the opinion that seems to him to be true. But there is no such thing as belief amongst animals, although there is imagination in many.§ 649

             Further: belief attaches to all opinion, and is due to conviction, which in turn is due to reasoning. Now imagination is found in some beasts; but reason in none.§ 650

             It is therefore evident, on these grounds, that neither opinion accompanying sensation, nor through sensation, nor a combination of opinion and sensation, will constitute imagination.§ 651

             And it is clear that opinion would have simply the same objects as sensation. I mean, that an imagining of 'white' would be a combination of the sensed 'white' and the opinion that it is white'. For it would not be produced by an opinion of 'white' and a sensation of 'good'. To imagine, then, would be having an opinion of the same thing as what one senses--the same absolutely speaking.§ 652

             False appearances, however, are possible about which at the same time one holds a true opinion: and indeed the Sun seems to be a foot across, yet is believed to be greater than the inhabited world. Therefore it comes about, either that one discards the true opinion which one had formed, the thing itself remaining, and one neither forgets nor ceases to hold [that opinion]: or, if one still retains it, the same must be both true and false. But a false [opinion] is produced if there is an unnoticed transformation in the facts. Imagination therefore is neither one of these, nor constituted from these.§§ 653-4