by Aristotle
[15] 7 · Why is it that we feel no pleasure in the contemplation or anticipation of the fact that the interior angles of a triangle are equal to two right angles, and similar geometrical truths—except in so far as we enjoy the speculation, and the pleasure of this is always the same and would be equally great if these angles were equal to three or more right angles—but we rejoice at the recollection of an [20] Olympic victory or the sea-battle at Salamis, and at the anticipation of such events, but not in their opposites? Is it because12 we rejoice in such events as having taken place or taking place, but as regards what happens in the course of nature the contemplation of the real state of affairs alone causes us pleasure, whereas actions [25] give rise to the pleasure caused by their results? Since, then, actions are various, their results too are sometimes painful and sometimes pleasant; and we avoid and pursue anything in accordance with pleasure and pain.
8 · Why do doctors continue their treatment only until health is restored? For the doctor reduces the patient, and next dries his body, then creates a healthy [30] condition and at that point stops. Is it because it is impossible for any other condition to be produced from health? Or, if it is possible, is it the task of another science, and will what is produced from health be something different? Now, if health is produced from conditions which are its opposite or are intermediate between health and sickness, it is obvious that the patient is sick because he is too moist or too dry or something else. The doctor, then, from a state of cold creates a [35] less extreme condition and, finally, a condition of a certain heat or dryness or moisture by change from the opposite or intermediate condition, until he achieves a state which is such as to constitute a condition of health; and from this no condition can be produced except one which is intermediate between health and sickness. The possessor of the art can, then, create some new condition; for, when he has reached a certain point, he can retrace his steps and undo his work; but the doctor’s art has nothing to do with such a course, for its aim is always to create a better condition. So neither the doctor’s art nor any other art will create anything else out of health; for [956b1] either nothing would be being produced, or else the opposite of health, if the same science were being employed (so too out of a house nothing could make its contrary): nor is there any other art13 which can make anything out of health, except as making a whole out of a part, as, for example, when the cobbler’s art makes a shoe out of the front part of a shoe; for these two things can be produced out of one another by two processes, one of composition and the other of destruction. [5]
9 · Why is it generally considered that the philosopher is superior to the orator? Is it because the philosopher spends his time in studying the actual forms of things, while the orator deals with what participates in them—the former considering what injustice and tyranny are, the latter urging that a certain individual is unjust or dealing with the character of a tyrant? [10]
10 · Why are theatrical artists generally persons of bad character? Is it because they partake but little of reason and wisdom,14 because most of their life is spent in the pursuit of the arts which provide their daily needs, and because the greater part of their life is passed in incontinence and often in want, and both these things prepare the way to villainy? [15]
11 · Why did the men of old institute prizes for physical contests but none for wisdom? Is it because in all fairness the judges should in the intellectual sphere be either the superiors or at any rate not the inferiors of the competitors? Now if those who were pre-eminent in wisdom had to compete and a prize had been offered, [20] they would have no one to act as judges. In athletic contests, however, anyone can judge by merely using his eyes. Further, the original institutor of the games did not wish to propose to the Greeks such a contest15 as would be likely to produce violent disputes and enmity; for when one is rejected or accepted in a contest of bodily [25] strength, men do not altogether harbour any grievance nor feel sentiments of enmity towards the judges, but they feel great wrath and indignation against those who decide their relative wisdom or worthlessness; and this is a quarrelsome and bad state of affairs. Furthermore, the prize ought to be better than the contest; for [30] in athletic games the prize is more desirable than, and superior to, the contest. But what prize could be found superior to wisdom?
12 · Why is it that man in particular thinks one thing and does another? Is it because the same science deals with contraries? Or is it because the intelligence has many objects, desire one? Now man usually lives by the intelligence, the animals by [35] appetite, passion, and desire.
13 · Why is it that some prudent men spend their time acquiring rather than using? Is it because they are following the habit of doing so? Or is it due to the pleasure of anticipation?
14 · Why do those who sleep deeply and most pleasantly see no visions? Is it because sensation and thought function because the mind is at rest? And this seems [957a1] to be knowledge because knowledge brings the soul to rest; for when it is in motion and being carried along it can neither have sensation nor think. Hence it is that children and those who are drunk and the insane are senseless; for, owing to the abundance of heat present in them, they are in a state of considerable and very [5] violent movement, but when this ceases they become more sensible; for, when the thought is undisturbed, they can control it better. Those who have visions during their sleep dream because thought is checked, and in proportion as it is at rest. For the mind is greatly moved during sleep, since, when heat collects in the interior from [10] the rest of the body, there is very considerable and violent movement; and it is not true, as most people suppose, that it is most at rest and by itself, and especially so when no vision is seen. The contrary is really true; for because it is in considerable movement and never rests for a moment, it cannot think. And it is naturally in most [15] movement when it sleeps most pleasantly, because it is then in particular that the greatest amount of heat collects in the interior of the body. That, when it is in motion, the mind cannot think, not only in its waking hours but also in sleep, is proved by the fact that one is least likely to see visions during the sleep which [20] follows the taking of food; now this is the time when the mind is most disturbed owing to the nourishment which has been introduced into the body. A vision occurs when sleep comes over us while we are thinking or letting things pass before our eyes. Hence we usually see things which we are doing or intend or wish to do; for it is [25] on these things that our thoughts and fancies most often dwell. And the better men are, the better are their dreams, because they think of better things in their waking hours, while those who are less well disposed in mind or body have worse dreams. For there is a close correspondence between the disposition of the body and the [30] images of our dreams; for, when a man is ill, the ideas proposed by his thoughts are bad, and furthermore, owing to the disturbance which reigns in his body, his mind cannot rest. It is for this reason that atrabilious persons start in their sleep, because, owing to the excess of heat, the mind is in a state of too much movement, and, when [35] the movement is too violent, they cannot sleep.
BOOK XXXI
PROBLEMS CONNECTED WITH THE EYES
1 · Why does rubbing the eye stop sneezing? Is it because by this means evaporation is given to the moisture? For the eye sheds tears after friction, and [957b1] sneezing is due to an abundance of moisture. Or is it because the lesser heat is destroyed by the greater? Now the eye when it is rubbed acquires more heat than is contained in the nose; and for this reason even if we rub the nose itself the sneezing stops.
2 · Why can one see more accurately with one eye than with both eyes? Is it [5] because more movements are set up by the two eyes, as certainly happens in those who squint? The movement of the two eyes, therefore, is not one, but that of a single eye is one; therefore one sees less accurately with both eyes.
3 · Why do the eyes tend to become very red in those who are angry, and the ears in those who are ashamed? Is it because the eyes are chilled in those who are [10] ashamed (for ‘shame dwells
in the eyes’), so that1 they cannot look straight in front of them? (Cowardice also involves a cooling in the same region.) Now the heat2 travels in a direction away from the forepart of the head, and the ears are situated in the opposite part of the head, and therefore they redden most under the emotion of shame. But under the influence of provocation assistance is sent to the more [15] sensitive and easily affected part, as though it were suffering violence; for in those who are frightened it fails altogether there.
4 · Why is it that, if one eye is held down, the other has a more intent gaze? Is it because the origins of sight in the two eyes are connected at one source? So when one eye moves, the common source of sight is also set in motion; and when this [20] moves, the other eye moves also. When one eye therefore is held down, all the movement will be concentrated on the other eye, which consequently will be able to gaze more intently.
5 · Why is it that those who are blind from birth do not become bald? Is it because the eye is injured by the presence of a large quantity of moisture in the region of the head? This is why they cauterize the veins round the temples of those [25] who suffer from running at the eyes (thus closing the ducts through which the humours flow), and scrape the head, cutting into the skin upon it. Since, therefore, it is the excretion gathering in the head which injures the eyes, this same excretion by collecting in too great quantities in the head might prevent the eyes from originally coming into being at all. And since the hair grows from excretions, and [30] the excretion in the head of those who are blind from birth is abundant, it is only natural that they are not bald.
6 · Why are those whose eyes protrude affected more than others by smoke? Is it because smoke reaches the projecting parts most quickly?
7 · Why is it that we can turn the gaze of both eyes simultaneously towards [35] the right and the left and in the direction of the nose, and that of one eye to the left or to the right, but cannot direct them simultaneously one to the right and the other to the left? Similarly, we can direct them downwards and upwards; for we can turn them simultaneously in the same direction, but not separately. Is it because the eyes, though two, are connected at one point, and under such conditions, when one [958a1] extremity moves, the other must follow in the same direction, for one extremity becomes the source of movement to the other extremity? Since, therefore, it is impossible for one thing to move simultaneously in contrary directions, it is impossible also for the eyes to do so; for the extremities would move in opposite [5] directions if one moved up and the other down, and the source of the movement of both of them would have to make corresponding movements, which is impossible. The squinting of the eyes is due to the fact that the eyeballs possess a moving principle and turn, to a certain extent,3 upwards and downwards and sideways. When, therefore, being so placed that they are in a similar position to one another [10] and midway between an upward and a downward and an oblique movement, the two eyeballs catch the visual ray on corresponding points of themselves, they do not have a squint and their gaze is perfectly steady (though when they catch the visual rays on corresponding points of themselves, although the vision does not squint they [15] differ.) Yet, if you turn up the whites of the eyes, part of the pupil is obscured, as for example in those who are about to sneeze; others have oblique vision, madmen for example; in others the gaze is turned towards the nose, as in tragic masks and in those who are nervous, for their glance denotes concentrated thought. But those who keep their gaze fixed on one point without having their eyeballs similarly situated, or who have them similarly situated but do not keep them fixed on the [20] same point, both these have squints; they therefore scowl and screw up the eyes, for they try to fix one eyeball in the same position as the other; so they leave one eye alone and try to bring the other into position. If the vision of both eyes does not rest on the same point,4 they must squint; for the same thing happens as in those to [25] whom, when they press under the eye, a single object appears double, for in these too the source of vision is disturbed. If, therefore, the eye is moved upwards, the terminus of the vision is lowered; if downwards, it is raised. And if the position of [30] one eye is changed, the object of the vision therefore seems to move up or down, because the vision also does so, but it does not appear double unless the vision of both eyes is in use. A similar squint5 occurs also in one whose eyes do not correspond, causing him to see double; but this is due to the position of the vision, because it is not in the middle of the eye.
[35] 8 · Why do those who are short-sighted write in small characters? For it is strange that those who have not acute vision should do what requires such vision. Is it because small things appear large when they are near at hand, and the short-sighted hold what they are writing close to their eyes? Or is it because they screw up their eyes when they write? For owing to the feebleness of their sight, if [958b1] they write with their eyes wide open, the vision, being dispersed, can only see dimly; but when the eyes are screwed up, it all falls on one point, and, since it forms a small angle, it necessarily causes the writing of small characters.
9 · Why can some people see more clearly after suffering from ophthalmia? Is it because their eyes are thus purged? For often the external thickening blocks [5] the vision, but is dissolved when the eye discharges. Hence also it is beneficial that the eyes should be made to smart, with onion for example; but a substance of the opposite kind, such as marjoram, has an adverse effect.
10 · Why are those who see with only one eye less liable to disturbance of the vision? Is it because their mind is less affected, and so the disturbance of the vision [10] is less felt?
11 · Why do objects appear double to those whose eyes are distorted? Is it because the movement does not reach the same point on each of the eyes? So the mind thinks that it sees two objects when it really sees one twice. A similar phenomenon occurs if one crosses the fingers; for a single object appears to be two to a single person touching it twice. [15]
12 · Why is it that the senses on the right side of the body are not superior to those on the left side, but in all other respects the right side of the body is superior? Is it a question of habit, namely, that we accustom ourselves immediately to perceive equally well with the senses on both sides of the body? And it seems that the superiority of the right-hand parts of the body is due to habit, for we can accustom ourselves to be ambidextrous. Or is it because to feel sensation is to be [20] passive, and the right parts of the body are superior in that they are more active and less passive than the left?
13 · Why is it that in all other respects the right side of the body is superior, but in sensation the two sides are alike? Is it because we habitually practise the equal use of sensation on both sides? Moreover, to feel sensation is to be passive, and [25] the superiority of the right side of the body is shown in activity, not in passivity.
14 · Why is physical exercise detrimental to acuteness of vision? Is it because it makes the eye dry, as it does the rest of the body? Now dryness hardens [30] every kind of skin; so it has that effect also on the skin covering the pupil. This is also the reason why the aged have not acute vision; for their eyes have a hard and wrinkled surface, and so the vision is obscured.
15 · Why do the short-sighted, though they have not acute vision, write in small characters? Yet it is characteristic of acute vision to see what is small. Is it [35] because, having weak sight, they screw up their eyes? For when the sight proceeds forth in a concentrated glance it sees better, but when the eye is wide open its vision is dispersed. So owing to the feebleness of their sight they bring their eyelids close together, and, because their vision proceeds from a small area, they see magnitude [959a1] on a small scale, and the characters which they write are on the same scale as their vision.
16 · Why do the short-sighted bring their eyelids close together when they look at anything? Is it due to the weakness of their sight, so that, just as a man in [5] looking at a distant object puts his hand up to his eyes, they close the eyelids to look at objects near at hand? They do so in order
that the vision may proceed forth in a more concentrated form, since it passes through a narrower opening, and that it may not be immediately dispersed by passing out through a wide aperture. A wider vision, however, covers a larger field.
17 · Why is it that if the eye be moved sideways a single object does not [10] appear double? Is it because the source of sight is still in the same line? It can only appear double when the line is altered upwards or downwards; and it makes no difference if it is altered sideways, unless it is also at the same time altered upwards. Why, then, is it possible in sight for a single object to appear double if the eyes are in a certain position in relation to one another, but impossible in the other senses? Is it [15] not the case also in touch that one thing becomes two if the fingers are crossed? But with the other senses this does not happen, because they do not perceive objects which extend to a distance away from them, nor are they duplicated like the eyes. It takes place for the same reason as it does with the fingers; for then the touch is imitating the sight.
[20] 18 · Why is it that, though in the rest of the body the left side is weaker than the right, this is not true of the eyes, but the sight of both eyes is equally acute? Is it because the parts of the body on the right side are superior in activity but not in passivity, and the sight is passive?
19 · Why is it that when we keep our gaze fixed on objects of other colours [25] our vision deteriorates, whereas it improves if we gaze intently on yellow and green objects, such as herbs and the like? Is it because we are least able to gaze intently on white and black (for they both mar the vision), and the above-mentioned colours come midway between these, so that, the conditions of vision being of the nature of a [30] mean, our sight is not weakened thereby but improved? Perhaps, just as we take harm from over-violent physical exertion but moderate exercise is beneficial, so too is it with the sight; for we over-exert the sight if we gaze intently on solid objects, but we do not strain it in looking at objects which contain moisture, since there is nothing in them to resist the vision. Now green things are only moderately solid and [35] contain a considerable amount of moisture; they therefore do not harm the sight at all, but compel it to rest upon them, because the admixture of their colouring is suited to the vision.