by Aristotle
[25] 9 · Why is it that the parts of plants and of animals which are not instrumental are all round—in plants, for instance, the stem and the shoots, and in animals the calves, thighs, arms, and chest—and no whole or part is triangular or polygonal? Is it due, as Archytas used to say, to the fact that in natural movement [30] the proportion of equality is always present (for he holds that all things move in a proportion), and that this is the only proportion which can return to itself, and so it forms circles and rotundities wherever it occurs?
10 · Why do extremities always take rounded forms? Is it because nature makes everything as excellent and as beautiful as the available material permits, [35] and a rounded form is the most beautiful, being as uniform as possible?
11 · Why does a circular object when it is thrown at first describe a straight line, but, as it ceases to move, describe a spiral, until it falls? Does it describe a straight line at first, because the air on either side of it alike keeps it upright? The [915b1] inclination then to either side being equal, the line also which it describes must be of such a nature that it divides the space on either side of it equally, and such a line is a straight line. But when it inclines to one side, because the air on either side of it is not even, it no longer describes an equal line with its inner and with its outer edge, but is forced to describe a circular line. [5]
12 · Why is it that in magnitudes of uneven weight,14 if you set the lighter part of them in motion, the object thrown revolves in a circle, as happens for example with loaded dice if you throw them with the unweighted side towards you? Is it because the heavier part cannot travel at the same speed as the lighter when [10] hurled with the same force? Now since it must necessarily move, but cannot do so in the same manner, that is in a straight line, it must take an inward direction and revolve; just as, if part of the object had as a whole remained motionless owing to a weight in the centre, the part next to the person setting the object in motion would have moved so as to occupy the position of the part away from him, while the farther side would have moved towards him. But when the whole object moves and, as it [15] travels, has a weight in the middle, it must necessarily behave in the same manner.
13 · Why is it that objects which are travelling along, when they come into collision with anything, rebound in a direction opposite to that in which they are naturally travelling, and at similar angles? Is it because they move not only with the impetus which accords with their own nature but also with that which is due to the [20] agent which throws them? Their own impetus then ceases when they reach their own proper position (for everything comes to rest when it reaches the position to which it is naturally carried), but, owing to the extraneous impetus, it is forced to continue to move, not, however, in a forward direction, because it is prevented from doing so, but either sideways or in a direct line. Now every object rebounds at [25] similar angles, because it is travelling to the point to which it is carried by the impetus which was imparted by the person who threw it; and at that point it must be travelling at an acute angle or at a right angle. Since then the repelling object stops the movement in a straight line, it stops alike the moving object and its impetus. As [30] then in a mirror the image appears at the end of the line along which the sight travels, so the opposite occurs in moving objects, for they are repelled at an angle of the same magnitude as the angel at the apex (for it must be observed that both the angle and the impetus are changed), and in these circumstances it is clear that moving objects must rebound at similar angles. [35]
BOOK XVII
PROBLEMS CONNECTED WITH ANIMATE THINGS
1 · Why do those who are unsymmetrical appear larger when set side by side with other men than by themselves? Is it because that which is symmetrical is one, and symmetry more than anything else gives unity to a thing, and that which is one [916a1] tends to be indivisible, and the indivisible is smaller, whereas asymmetry by causing diversity creates a multiplicity? When things therefore are seen by themselves, their dimensions are less likely to be noticed; but this is not so when they are seen side by [5] side with one another. That then which is indivisible appears to be one, and the impression which it makes on the beholder is one because of its symmetry. But that which is unsymmetrical makes a greater impression, as though it were many, and appears greater because, though in reality only one, it seems to be many; for it partakes of the nature of magnitude, because it is continuous, and of number, [10] because of the inequality of its parts; and so being increased in both these respects, it naturally appears great by the side of that which is simple and one.
2 · Why do animals and plants grow more in length than otherwise? Is it because length increases three times over, width twice, and depth once? For length [15] is the first and original dimension, and so it increases both of itself, and secondly in combination with width, and thirdly in combination with depth. But width implies an increase in two dimensions only, in itself and at the same time in depth.1
In what sense must we understand the terms ‘prior’ and ‘posterior’? As those who lived in the time of Troy are prior to us, so are those who lived before them prior [20] to them and so on ad infinitum? Or since there is a beginning and a middle and an end of the universe, and when a man, as he becomes old, reaches the limit and turns again towards the beginning, that which is nearer to the beginning is earlier, what prevents our being nearer to the beginning than to the end, in which case we should [25] be prior? Just as the course2 of the firmament and of each of the stars is a circle, why should not also the coming into being and the decay of perishable things be of such a kind that these things again come into being and decay? This agrees with the saying that ‘human life is a circle’. To demand that those who are coming into being [30] should always be numerically identical is foolish, but one would more readily accept that they were identical in kind. And so we should ourselves be prior, and one might suppose the arrangement of the series to be such that it returns back in a circle to the point from which it began and thus secures continuity and identity of composition. For Alcmaeon declares that men perish because they cannot link [35] together the beginning to the end—a clever saying, if one supposes that he uses it metaphorically and the literal meaning is not insisted upon. If then human life is a circle, and a circle has neither beginning nor end, we should not be prior to those who lived in the time of Troy nor they prior to us by being nearer to the beginning.
BOOK XVIII
PROBLEMS CONNECTED WITH LITERARY STUDY
1 · Why is it that some people, if they begin to read, are overcome by sleep [916b1] even against their will, whereas others wishing to be overcome by sleep are kept awake by taking up a book? Is it because in those in whom movements of breath take place owing to the coldness of their nature or of melancholic humours, which [5] by their coldness engender an unconcocted excretion of breath—in such people, the intelligence, when it is set in motion and does not think of anything with concentrated attention, is checked by the second movement, which has a cooling effect, and this causes a tendency to sleep? But when they fix the intelligence firmly upon something, as happens in reading, they are impelled by the heating movement, [10] which is unchecked by anything, and so they cannot go to sleep. In those who are in a natural condition, however, when the intelligence, which is very powerful, stands at a single point and does not keep changing from one subject to another, every function in that region (whose inactivity involves sleep) is at a standstill;1 and when the intelligence stands still and is as it were weary, being situated in the head, it [15] weighs it down and produces sleep. But as long as the mind moves naturally, it does not go to sleep; for it is then that it is most alive, and wakefulness rather than sleeping is the cause of life.
2 · Why are contentious disputations useful as a mental exercise? Is it because they involve frequent victories and defeats? They therefore quickly instil a [20] spirit of rivalry; for, when men are victorious, they are induced by their joy to contend yet more, and, when they are defeated, they continue the strug
gle in hopes of turning defeat into victory. Those engaged in struggles of other kinds act in the same way, and so when fighting and getting the worst of it often refuse to come to terms.
3 · Why is it that in rhetorical displays men prefer examples and stories [25] rather than enthymemes? Is it because they like to learn and to learn quickly, and this end is achieved more easily by examples and stories, since these are familiar to them and are of the nature of particulars, whereas enthymemes are proofs based on generalities, with which we are less familiar than with the particular? Further, we [30] attach more credence to any evidence which is supported by several witnesses, and examples and stories resemble evidence, and proofs supported by witnesses are easily obtained. Further, men like to hear of similarities, and examples and stories display similarities.
4 · Why do we talk of an orator, or a general, or a business man as being [35] clever, but not use the term of a musician or of an actor? Is it because the powers of the two last are exercised apart from any desire of gaining an advantage (for their aim is pleasure), whereas the three first aim at some advantage? For a good orator [917a1] or general or business man is one who can gain some advantage, and cleverness consists mainly in getting the better of some one else.
5 · Why is the philosopher generally regarded as superior to the orator? Is it because the philosopher treats of the nature of injustice, while the orator says that such and such a person is unjust, and the orator states that such and such a person is [5] a tyrant, while the philosopher discusses the nature of tyranny?
6 · Why is it that some men spend their time in pursuits which they have chosen, though these are sometimes mean, rather than in more honourable professions? Why, for example, should a man who chooses to be a conjurer or an actor or a piper prefer these callings to that of an astronomer or an orator? Is it [10] because some men would prefer to undertake the more honourable professions but do not do so because they do not feel confident that they would succeed in them? Or is it because each man chooses the calling in which he thinks he can excel and devotes himself to that which he chooses, giving up the greater part of each day to it, in order that he may improve his own proficiency in it? Now when men have chosen [15] a calling from the first and have become accustomed to it, they lose the power of discriminating between the higher and the lower; for their mind is warped by their bad choice.
7 · Why is it that some persons, if they begin to read, are overcome by sleep even against their will, whereas those who wish to go to sleep are made unable to do [20] so if they take up a book?2 Is it because in those in whom movements of breath take place owing to the coldness of their nature or of melancholic humours, which by their coldness engender an unconcocted excretion of breath—in these when the intelligence is set in motion and does not think of anything with concentrated attention, the intelligence is checked by the second movement,3 and so they undergo [25] a great mental change and go to sleep (for the movement of breath is overcome)? But when they fix their intelligence on something, as happens in reading, they are impelled by the movement of breath unchecked by anything, and so cannot sleep. But in those who are in a natural condition, when the intelligence is fixed on one [30] thing and does not keep changing from one subject to another, every function in that region (the inactivity of which involves sleep) is at a standstill. (Similarly during a rout, if the leader halts, all the forces under his command halt also.) For naturally that which is light rises, while the heavy sinks. As long, therefore, as the mind moves naturally, it does not go to sleep; for it is then that it is most alive.4 When the mind [35] stands still and is as it were weary, the intellect undergoes a change, and the corporeal elements rise to the head and produce sleep. Reading might be expected to prevent sleep; but wakefulness is not due to the fact that we are thinking (for then our mind is most concentrated) but to the constant change; for the intellectual activities which cause wakefulness are those in which the mind searches and finds [917b1] difficulties rather than those in which it pursues continual contemplation; for the former cause lack of concentration, while the latter do not.
8 · Why is it that in contentious disputes no verbosity can ever occur? Is it because such reasoning is apparent deduction, and deduction involves only a brief [5] discussion; and, if it be prolonged, after a time the false reasoning is detected and the disputant can withdraw the premisses which he has granted?
9 · Why do we feel more pleasure in listening to narratives in which the attention is concentrated on a single point than in hearing those which are concerned with many subjects? Is it because we pay more attention to and feel more [10] pleasure in listening to things which are more easily comprehended, and that which is definite is more easily comprehended than that which is indefinite? Now a single thing is definite, but a plurality partakes of the nature of the infinite.
10 · Why do we like to hear of events which are neither very old nor quite new? Is it because we discredit events which occurred long before our time and take no pleasure in events which we discredit, while we can still as it were perceive very [15] recent events and so take no pleasure in hearing about them?
BOOK XIX
PROBLEMS CONNECTED WITH MUSIC
1 · Why do those who are grieving and those who are enjoying themselves alike have the flute played to them? Is it in order that the distress of the former may be lessened and the pleasure of the latter increased? [20]
2 · Why is it that, when the same person uses the same vocal power, the sound travels farther when he is singing or shouting with others than when he does so by himself? Is it because the doing of anything with a number of other people—compressing, for instance, or pushing something—does not produce an effect in simple proportion to the number of persons; but, just as a line two feet long describes a circle which is not double but quadruple that described by a line a foot long, so collective actions have greater force in proportion to their number than [25] when they are carried out separately? When, therefore, a number of persons sing together, the force of their voice unites, and impels the air simultaneously, so that it travels many times as far; for the voice produced by all is the multiple of each single voice.
[30] 3 · Why does the voice waver most when singing parhypate and to no less a degree than when singing nete and the higher notes, although the interval is greater? Is it because the interval is more difficult to sing and is in primary element? Now the difficulty is due to the straining and pressure of the voice; and these require an effort, and things which require an effort are more likely to fail.
[35] 4 · But why is parhypate difficult to sing, but hypate easy, although there is only a quarter-tone between them? Is it because hypate is accompanied by relaxation of the voice and also because after tension it is easy to slacken?1 It is probably for the same reason that what a man says with violence,2 he says with this note or paranete. For one must… with a consciousness of the character which one [918a1] is representing and under conditions most akin to it according to one’s purpose. But what is the cause of concordant music?3
5 · Why do men take greater pleasure in listening to those who are singing such music as they already know than music which they do not know? Is it because, [5] when they recognize what is being sung, it is more obvious that the singer is as it were achieving his aims, and this is pleasant to contemplate? Or is it because it is less4 pleasant to learn? And the reason for this is that in the one case there is acquisition of knowledge, in the other the use and recognition of it. Further, that which is familiar is always pleasanter than the unfamiliar.
[10] 6 · Why does recitation with a musical accompaniment have a tragic effect when introduced into singing? Is it owing to the resulting contrast? For the contrast gives an expression of feeling and implies extremity of calamity or grief, whereas uniformity is less mournful.
7 · Why did the ancients, when they gave the scale seven notes, leave in [15] hypate and not nete? Is this a false statement, since they left in both and omitted trite, or is the truer answer that th
e lower note contains the sound of the higher note,5 so that hypate gives the impression of the octave above better than nete for the high note is a sign of more force, while the low note is easier to utter?
8 · Why does the low note contain6 the sound of the high note? Is it because [20] the low note is greater and resembles an obtuse angle, while the high note resembles an acute angle?
9 · Why do we listen with greater pleasure to a solo when a man sings it to the accompaniment of a flute or lyre? Yet the same tune is sung note for note with or without accompaniment. For if there is more of the same thing, it ought to be still more pleasant when accompanied by a large number of flute-players. Is it because [25] the singer is more obviously achieving his aim when he is accompanied by a flute or lyre? And the accompaniment of a number of flute-players or lyres does not add to the pleasure, because it drowns the singing.
10 · Why, if the human voice is more pleasant than an instrument, is the voice of a man singing without words—as, for example, when singing nonny-noes—not [30] so pleasant as a flute or lyre? Or is it true that even in the case of an instrument we get less pleasure if it is not expressive of meaning? The instrument, however, has an advantage even in its actual effect; for while the human voice is pleasanter, instruments strike the note better than the human mouth, which is why they are pleasanter to hear than nonny-noes.