LECTIO EIGHT

             § 107. Having stated Plato's opinion, Aristotle now proceeds to its refutation. Here we should note that often, in criticising Plato, it is not precisely Plato's own meaning that Aristotle criticises, but the obvious sense of his words. He has to do this because Plato's method of teaching was faulty; he constantly used figures of speech, teaching by symbols and giving his words a meaning quite other than their literal sense; as when he calls the soul a circle. So lest anyone should be led astray by this literal sense, Aristotle sometimes argues precisely against it, in criticising Plato.

             § 108. Against the above-mentioned opinion, then, he brings ten arguments, some of which bear on Plato's own view, and some on the literal sense of his words. Plato did not really mean that the intellect was anything quantitative or circular; he was talking metaphorically. Still, lest there should be any mistake about this, Aristotle argues on a literal interpretation of the words.

             § 109. In the first argument, then, he explains what 'soul' Plato had in mind, that it was the Soul of the Universe, and that 'that' (soul) which is 'of the whole', i.e. of the Universe, is exclusively intellectual, according to Plato. It is not vegetative, since it needs no nourishment; nor sensitive since it has no organs of sense; nor appetitive since appetite follows sensitivity. Indeed it could not in any sense be sensitive or appetitive, granted that the movement of the Universal Soul is circular; because neither sense nor appetite moves in a circle (for sense does not reflect upon itself) but only the intellect (which does reflect upon itself, as when a man knows that he knows). So Plato concluded that the World-Soul was only intellectual, and said that intellect itself was a sort of spatial magnitude and a circle.

             § 110. Aristotle denies this, saying that Plato was wrong in representing the soul as a spatial magnitude circular in shape, and in dividing it into two circles.

             § 111. And he points out where Plato went astray. In this matter of the nature of the soul we have to base our judgement concerning any of its faculties upon the act or operation of that faculty, and our judgement concerning the act or operation upon the object of this act or operation; for faculties are known by their acts, and acts by their objects. Thus in the definition of a faculty is included its act, and in the definition of an act its object. Now it is clear that a thing gets its unity from whatever gives it being and specific nature. If then the intellect gets its being and specific nature from the intelligible which is its object (I speak of the intellect in act, which as such is nothing before the act of understanding occurs) it is clear that if it is one and continuous, as Plato held, it will be so in the same way as intelligible objects are one and continuous. For the intellect is one only in the same way as its operation (understanding) is one; and its operation is one only in the same way as its object is one; since acts are differentiated according to their objects. Since then the intellect's object is intelligibles, and intelligibles compose a unity, not like a magnitude or a continuum, but like numbers which follow in a series, it is clear that the intellect is not, as Plato thought, a magnitude. It is either indivisible, as it is the nature of first principles to be, or, if it is continuous, it is so not as a magnitude but as number is; for as one number leads to another, so do we understand one object after another. And frequently several numbers terminate in one, as the premisses in a syllogism terminate in one conclusion.

             § 112. The second argument comes at 'How would it understand'. For it might be answered that Plato's reason for attributing magnitude to the intellect was not that there are many intelligibles, but that each intelligible by itself shows it to be a magnitude.

             § 113. But this will not do. For Plato maintained that the act of understanding was not a reception of intelligible forms into the mind, but a sort of contact (as of a circle, we have seen) due to the mind's going out to meet intelligible forms. But I ask you, how precisely does the mind understand by contact, if it is a magnitude? It must touch its object either with the whole of itself or with a part. But if with the whole of itself, then its parts are not needed and there is no necessity for supposing that the intellect is a magnitude or a circle. If, on the other hand, it touches with some of its parts, and thus understands in part, then either several of its parts are involved or only one. If only one, then again the other parts are superfluous and we need not suppose that the intellect has parts. But if it understands by touching with all its parts, these must be either points or quantities; and if points, then, since the number of points in any magnitude is infinite, the intellect would have to touch its object an infinity of times before it understood the latter at all; and thus it never would understand, since infinity cannot be traversed.

             § 114. Aristotle says 'points' not because he thought that a magnitude could be partitioned into points, but as disputing with Plato who regarded bodies as composed of planes, planes of lines, and lines of points; an opinion refuted by Aristotle in the Physics, Book VI, where it is shown that a point added to a point makes no difference.

             § 115. But if the mind understands by touching with quantitative parts, then, as each part is divisible into many, it must understand the same object many times over. Again, since any quantity is infinitely divisible into parts that are proportionately, not quantitatively, the same, it would follow that the mind understands the same thing an infinite number of times,--which raises difficulties. It would seem then that it touches its object once only, and that it cannot be called a magnitude, either with respect to many intelligibles or to only one.

             § 116. Notice that Aristotle is implying here that intellect is indivisible of its nature. What is intelligible in any thing is its essence or nature; which is present wholly in every part of it, as the specific nature is wholly present in each individual of the species; the whole nature of man in each individual man; and the individual as such is indivisible. Hence what is intelligible in anything is indivisible; and therefore so is the intellect.

             § 117. The third argument comes at 'Again, how'. Granted that the mind is indivisible, we can easily see how it can understand both the indivisible and the divisible. It understands the indivisible in virtue of its own nature which is indivisible; and the divisible by abstracting from divisibility. But once allow, with Plato, that mind is divisible, it becomes impossible to understand how it can think of the indivisible. Hence the difficulty of admitting Plato's theory.

             § 118. The fourth argument begins at 'It is necessary'. It runs thus. You say that intellect is circular and in movement. Now the movement of circles is a circling and that of the intellect is understanding; hence if intellect is a circle, understanding must be a circling. But this is false; for, since circular movement has no actual beginning or end, as is shown in the Physics, Book VIII, it would follow that understanding, the proper act of the intellect, never reached a term. But understanding has an actual beginning and end: hence it is not the same as circular movement, and therefore the intellect is not a circle.

             § 119. That understanding has an actual beginning and end can be proved in this way. All thinking is either practical or speculative. Clearly all practical thinking reaches a term or end; for it is all for the sake of something else, namely a work to be done, and in this work it terminates. And speculative thinking too has its proper end, namely ideas; for it always comes to rest in some idea: either in a definition, when the mind simply apprehends something, or in demonstrations, when it combines and distinguishes things. But the first demonstrations begin from absolute first principles and terminate, in their turn, in the conclusions of syllogisms.

             § 120. If it be objected that one conclusion follows another, and thus there is no definite end, I answer that conclusions are nevertheless not circular. For, as is shown in the Posterior Analytics, Book I, demonstration cannot go in a circle; it always goes in a straight line; and an infinite movement or progression in a straight line is impossible.

             § 121. Definitions too have a beginning and an end, for you cannot go on to infinity in the enumeration of genera; the most general genus has to be taken as the first one. Similarly in enumerating species; you cannot particularise to infinity, but must stop at the most particular species. Hence the most general genus is the beginning, and the most particular species is the term or end, in definitions. Clearly, then, every act of the mind has an actual starting point and term.

             § 122. The fifth argument begins at 'Further, if'. In a sense this argument depends on the previous one and is a part of it. It has been shown that if the intellect were a circle, as Plato thought, understanding would be a circling; and in the preceding argument Aristotle has shown that understanding is not a circling; which he now proves once more in the following way. The difference between a circular motion and any other motion lies in this, that the latter can never be repeated on the same quantity. This becomes clear if we think of the different kinds of movement in particular. Thus the movement of 'alteration' cannot be repeated in the same subject in the same respect; for the same thing is not in the same respect changed from white to black and black to white. So too in the movement of growth, the same thing cannot in the same respect both increase and diminish. So also in local movement; if this goes in a straight line it must have two actual terms; and if it is to be repeated, the term at the end of the movement must be used twice, once as end and once as beginning, and, since there must intervene a moment of rest at that term, it is not exactly the same movement. In circular motion alone can one and the same movement be many times repeated according to the same quantity; the reason being that in circular motion there are no actual terms; hence, no matter how often it is repeated, no interval of rest intervenes nor does the motion vary in any way.

             § 123. This being granted, Aristotle argues as follows. If you say that the intellect is a circle, then the act of thinking must be a circular motion. But this consequence is not admissible; therefore neither is the premiss.

             § 124. He then shows that the consequence is not admissible. Granted, he says, that the same circular movement is multiplied, that is, repeated, in the same respect. If thinking, then, is a circular movement, as you say, it will be repeated again and again as one and the same movement bearing upon one and the same object; and so the mind will think the same thing many times over. For the mind, in moving, touches and by this touching it thinks, as they say. If then its motion is circular it touches and thinks the same thing over and over again; which gives rise to difficulties.

             § 125. The sixth argument, at 'Moreover, intelligence' is as follows. If thinking is, as you say, a circular motion, it should be associated with movement, but in fact the contrary is true; thinking is associated rather with repose. This Aristotle himself teaches in Book VII of the Physics, where he says that if a man is to become wise he must first achieve an inward tranquillity; which is why the young and the restless are not, as a rule, wise. Wisdom and prudence are acquired, says Aristotle, by one who is content to sit down and be quiet.

             § 126. But lest it be said that, while this is true of simple apprehension, it is not true of syllogistic reasoning, he adds that reasoning also is more like a repose than a movement. Because, of course, before the syllogism is complete the mind and intellect are swaying from one conclusion to another and resting in neither; but when it is finished the mind holds on to one conclusion and rests in it.

             § 127. The seventh argument, at 'Again, that, etc.', runs as follows. Let us agree that thinking makes the soul happy. Now happiness cannot reside in anything violent or coercive, since it is the soul's perfection and last end. As then movement is not of the soul's essential nature, but is indeed alien to it, that operation in which the soul finds its happiness, namely understanding, cannot be a movement, as Plato maintained. But that movement is not of the soul's nature is implied by Plato's own theory, for he said that the soul was first constituted by numbers, and then that it divided into two circles and was reflected into seven, from which followed movement. According to this view, then, movement is in the soul not naturally but accidentally.

             § 128. The eighth argument, at 'It must be burdensome', goes as follows. It seems to have been Plato's view that it was not of the nature of the soul to be joined to the body; for he said that it was first constituted of the elements and then compacted with the body, so that it cannot leave the body at will. Well then; whenever one thing is united against its nature to another, and cannot leave it at will, the resulting state is painful; and whenever a thing deteriorates through its union with another thing the union is harmful and to be avoided. But ex hypothesi the union of soul and body is contrary to the soul's nature; nor can the soul break away at will; and the result is bad for the soul, as the Platonists are always saying. Apparently, then, union with the body is a painful and fearful thing for the soul; which hardly squares with Plato's own theory that the soul is composed of elements and compacted with its body from the beginning.

             § 129. The ninth argument, at 'It is not clear', is as follows. Plato speaks of the Soul of the Universe and says it moves round in a circle. But this provides no explanation of the circular movement of the heavens; that is to say, it does not define the cause of it. For if the heavens move in a circle, this must be due either to intrinsic principles or to some extrinsic purpose. If intrinsic principles are the cause, the 'nature' in question will be either that of the soul or of the heavenly bodies. But it cannot be the soul's nature, for circular movement is not of the essence of the soul, but is accidental to it; for, as we have said, the nature of the soul is to 'move in a straight line' which is then 'bent into circles'. Nor can the cause be the nature of the heavenly bodies, for body as such is not the cause of the soul's movements, but rather the soul of the body's. But, if the cause is an extrinsic purpose, one cannot, on Plato's principles, point to any definite end in answer to the question why the heavens move in a circle rather than in any other way; unless one brings in the will of God. God has indeed, for some reason, chosen to move the heavens rather than leave them motionless, and to move them in a circular way. But why he does this Plato cannot tell. However, as this matter belongs rather to 'other contexts', i.e. to another treatise (the De Coelo), we can leave it aside for the present.

             § 130. The tenth argument starts at 'Another absurdity'. It is effective not only against Plato, but against many others also. It runs thus. It is clear that there must always be some proportion between mover and moved, agent and patient, form and matter. Not every form suits every body in the same way, nor does every agent act upon every patient. Nor, again, does every principle of movement move everything capable of receiving movement. There must be some correlation and proportion between them by which the one is naturally the mover, the other the moved in each case. Now obviously these philosophers admitted that the soul was in the body and moved it. Since then they spoke of the nature of the soul, it seems that they should also have had something to say about the nature of the body; about why the soul is joined to the body and how the body is related to and contrasts with the soul. Their study of the soul was inadequate so long as they discussed it alone and neglected to explain the nature of the body that receives it.

             § 131. Indeed, we may associate their thesis (Aristotle goes on to say) with the Pythagorean fable that any soul can enter any body; the soul of a fly for instance might perchance enter the body of an elephant. This cannot in fact happen; for the body of each particular thing, and especially of living things, has its own form and species and type of movement: hence there are great differences between the bodies of a worm, a dog, an elephant and a gnat. When they say that any soul can enter any body, it is as if one were to say that the art of weaving could enter flutes, or that the art of the coppersmith could enter a weaver's loom. If it was in the power of these arts to enter bodies or instruments they would not do so indiscriminately, but the art of playing the flute would enter flutes, and not lyres, while the art of playing stringed instruments would enter stringed instruments and not flutes. In the same way, if there is a body for every soul, any soul does not enter any body; rather the soul shapes the body fit for itself; it does not enter a ready-made body. Plato and the others who speak only about the soul are too superficial; they fail to define which body answers to which soul, and the precise mode of existence of each in union with the other.

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