by Aristotle
35 · Why is it that short walks are fatiguing? Is it because one often comes to a standstill and there is no uniform movement in the joints, and this is [10] fatiguing?
36 · Why do those who stand still in the sun become warmer than those who move, and this although movement is productive of heat? Is it true that every kind of movement does not produce heat, but some kinds have a cooling effect, as happens, for example, when one blows upon or keeps in motion kitchen-pots which [15] have boiled up? If then the heat remains when one stands still and, doing so, heats us more than if it were in motion (for our own body always gives off a warm steam, which heats the neighbouring air, as though there were a burning brand there), then, if we remain motionless, the air surrounding us becomes warm for the reasons [20] already stated; whereas, if we move, a wind is set up which cools us, for wind always has a cooling effect.
37 · Why is it that those who ride on horseback water more freely at the eyes the quicker the horse goes, and those on foot the quicker they run? Is it due to the [25] fact that the air which meets them is cold? For cold causes the eyes to water; for by contracting and solidifying the flesh it purges out the moisture. Or is the reason the contrary of this, namely, that the heat causes perspiration, and watering at the eyes is a form of perspiration? Therefore both perspiration and watering at the eyes are [30] due to heat and are alike salty; and it is movement which causes heat. Or is it due to the impact of the air? For as blasts of wind coming from an opposite direction trouble the eyes, so too the quicker a man drives or runs the more does the air deal a gentle blow, and this causes the eyes to water, because the ducts of the eye are [35] rarefied by the blow; for every blow has the effect either of cleaving or crushing.
38 · Why is it that fatigue must be cured in the summer by baths, in the winter by anointing? Is it because the latter, owing to the cold and the changes which it causes in the body, must be got rid of by heat, which will cause warmth, and olive-oil contains heat? In summer, on the other hand, the body requires moisture; for the season is dry and chills are not engendered, because it is warm. A [885a1] sparing diet of solid food and a liberal indulgence in liquid nourishment are characteristic of the summer, the latter being peculiar to the summer, while the former is commoner than at other seasons; for indulgence in drinking is peculiar to the summer because of the dryness of the season, but a sparing diet is found at all seasons, but is more general in the summer; for then owing to the season more heat is engendered by food. [5]
39 · Why is it that those who are running vigorously experience the greatest shock, if any one impedes them in their course? Is it because a thing is being drawn apart most vigorously when it is being dragged or moved violently in a contrary direction? If therefore any one impedes one who is running and whose limbs are being vigorously thrust forward, the result is that he wrenches him back at the same [10] time as his limbs are still moving forward, and so the more vigorously he is running the more violent is the shock which he receives.
40 · Why is it that walking along roads over uneven ground is less fatiguing than along a flat, straight surface? Is it because an upright carriage is natural to [15] everybody, but walking over even surfaces is more fatiguing than over uneven ground, since walking over even ground causes a continuous strain on the same members, whereas walking over uneven ground distributes the strain over the whole body? Now walking in warm weather tends more to make the body thin than in cold weather; for it causes more strain upon the outer parts, and so causes thinness by [20] engendering perspiration. Walking in cold weather makes the flesh more solid and causes a great desire for food; for it engenders an increase of heat in the inner parts and, since they become less liable to be affected by the cold, it cleans the inner [25] region by increasing the heat there, while it makes the flesh firm, since it cannot prevail over the whole of it. In like manner walking uphill is a greater exertion and tends more to cause thinness than walking downhill. For walking uphill causes most strain to the loins (whereas walking downhill is most trying to the thighs, for the whole weight falls upon them and so usually causes fatigue in them); for as they are [30] forcibly carried7 upwards in an unnatural manner, heat is engendered. Walking uphill therefore induces perspiration and causes thinness by heightening the respiration and engenders pain in the loins; for the legs, being lifted with difficulty, cause the loins to bend and draw them up, which naturally causes a very great [35] strain. Walking on hard, resisting ground causes fatigue to the muscles and tendons of the legs; for it causes tension in the sinews and muscles, because the pressure upon them is violent. Walking on soft ground is fatiguing to the joints; for it causes [885b1] frequent bending of the joints, because the surface trodden gives way. This is the same problem.
[5] 41 · Why do we walk with difficulty up a steep slope? Is it because all progression is made up of raising the feet and putting them down again? Now raising the foot is unnatural and putting it down is natural, while putting the foot forward is a mean between the two. Now in walking up a steep slope the unnatural motion preponderates.
[10] 42 · Why are riders on horseback less likely to fall? Is it because owing to their fear they are more careful?
BOOK VI
PROBLEMS CONNECTED WITH THE POSITIONS ASSUMED IN LYING DOWN AND IN OTHER POSTURES
[15] 1 · Why is it that sitting down makes some persons fat and others lean? Is it because bodily conditions differ, some men being hot, others cold? Those therefore who are hot grow fat (for the body owing to its heat prevails over the nourishment); but those who are cold, owing to the fact that their body requires heat introduced [20] from without and derives it chiefly from movement, cannot concoct their food while they are at rest. Or is it because the hot are full of superfluities and require movement to expend them, while the cold are not so?
2 · Why is it necessary that the parts of the body should be distended, as happens when a man takes athletic exercise? Is it because the ducts must be purged [25] by their own breath?
3 · Why is it better to lie in a curved position and why do many physicians prescribe this? Is it because the stomach concocts food more quickly when it is kept warm, and it keeps warmer in this position? Furthermore it is necessary to give the vapours a place where they can settle; for then there is less likely to be pain from [30] flatulence. (It is on this account that swollen veins and abscesses of all kinds help to restore a healthy condition, because they form hollows in which they receive the vapours.) When the body then is extended no hollow is formed (for the internal organs occupy all the space); but a hollow is formed when the body is curved.
[35] 4 · Why is dizziness more likely to occur in those who are standing than in those who are sitting? Is it because, when one is still, the moisture all inclines to one part of the body? This is why raw eggs cannot be spun round and round but fall over. The same thing occurs when the moisture in the body is put in motion. So one [886a1] stands up after having been at rest, when one is in this condition; but one sits down after having been in motion, when the moisture is evenly and uniformly distributed.
5 · Why is it that sleep comes more readily if one lies on the right side? Is it because the conditions when we are awake and when we are asleep are the contrary of one another? Since, therefore, when we are awake we recline on the left side, the [5] contrary will occur when another principle, namely, the contrary, is at work. Or is it because sleep is the absence of movement? The parts then of the body which are most active must be at rest; and the parts of the body on the right are most active. So, if one is lying on this side, a waking principle is as it were enchained.
6 · Why does one feel numbness? And why more in the hands and feet than [10] elsewhere? Is it because numbness is a process of cooling, being due to deprivation of blood and its transference elsewhere? Now these parts, especially the feet, are least fleshy and most muscular, and so they are naturally disposed to cool quickly.
7 · Why do we find it comfortable to recline on the left side, but sleep better [15] on the right
side? Is it because by turning away we avoid looking towards the light, since in the dark sleep comes on more readily? Or is it because we keep awake when reclining on the left side, and in this position we can easily employ ourselves in any particular function; and so for the contrary purpose the contrary position1 is advantageous; for each position invites to a particular function. [20]
BOOK VII
PROBLEMS CONNECTED WITH SYMPATHETIC ACTION
1 · Why do men generally themselves yawn when they see others yawn? Is it [25] because, if they are reminded of it when they feel a desire to perform any function, they then put it into execution, particularly where the desire is easily stirred, for example, that of passing urine? Now a yawn is a breath and a movement of moisture; it is therefore easy of performance, if only one sees some one else yawning; for the yawn is always ready to come.
2 · Why is it that, although we do not imitate the action if we see a man stretching out his hand or foot or doing anything else of the kind, yet we ourselves [30] yawn if we see some one else doing so? Or does this not always occur, but only when the body happens to feel a desire and is in such a condition that its moisture becomes heated? For then it is recollection which gives the impulse, as also in sexual desire and hunger; for it is that which causes recollection to exist that provides the stimulus towards the condition observed in another person. [35]
3 · Why is it that if we stand by a fire we desire to pass urine, and if men stand near water (for example, near a river) they actually pass urine? Is it because [886b1] water in general reminds us of the water in our own bodies, and the neighbourhood of water incites our internal moisture to come out? Fire of itself dissolves anything which is solidified in the body, just as the sun melts the snow.
4 · Why is it that those who come into contact with certain diseases become [5] affected by them, but no one ever becomes healthy through contact with health? Is it because disease is a state of movement, while health is a state of rest? If so, disease can set up movement, but health cannot. Or is it because disease comes to us against our will, while health comes by our own wish? Things then which occur against our will are different from those which occur by our wish and deliberate choice.
5 · Why is it that not only do some unpleasant sounds make us shudder—for [10] example, when a saw is being sharpened, or pumice-stone cut, or a stone ground—but the signs of effects produced in others conveyed by the sight cause those very effects in ourselves? For our teeth are set on edge when we see others eating anything bitter, and some people faint when they see any one being [15] strangled. Is it because every sound or noise is a breath, and this penetrating into us naturally causes disturbance? Now it will cause greater disturbance if it comes either in great quantity or with an unusually violent impact, setting up a new condition or causing some alteration within us. Therefore breaths which, though large in bulk, are yet soft, stir the actual seat of sensation, and such have a pleasant [20] effect; but those which are rough, causing a violent impact, shake the seat of sensation and affect a wide area owing to the force of their impact. Now things which are cold also affect a wide area, for coldness is a kind of force; therefore, as has been already said, it causes shuddering. But things which are rough, because they cause a series of frequent impacts, striking on the base of the hair thrust it in [25] the opposite direction; for when the hair is thrust out, its ends must necessarily assume a contrary position, with the result that it stands upright; for hair always naturally lies flat. The direction taken by the breath which is conveyed to the body by the hearing is downwards from above. The sounds, therefore, which we have mentioned being harsh, the hair bristles for the reasons stated. The bristling occurs [30] more on the rest of the body than on the head, because the hair there is weaker and the effect produced is weaker. The sensation produced by hearing being blunter than that produced by sight, the effects produced by it are confined to the surface of the body; the bristling of the hair is an effect of this kind, so it occurs from many dissimilar causes. The sensation produced by sight being very distinct, its results too are correspondingly more distinct; therefore the same effects are produced by it as [887a1] occur in reality, but more mildly than in reality. But as a result of hearing our hair stands on end for fear, not of the actual sounds, but of the anticipation which they arouse; for it is an anticipation of grievous ill.
6 · Why is yawning caused by the sight of others yawning, and so also the passing of urine, particularly in beasts of burden? Is it due to recollection? For [5] when recollection occurs the part of the body concerned is stimulated. In men then, because their sensations are finer, when they see something stimulation and recollection occur simultaneously. But in the beasts the sight is not sufficient by itself, but they require another sense to be called into activity; so the sense of smell must also be employed, this being a more easily stimulated sense in unreasoning [10] animals. So the other animals always pass urine in the same spot as the first one; for the stimulus is most acute when the sense of smell is employed; and the sense of smell is called into play when they are near the spot.
7 · Why is it that when we see any one cut or burned or tortured or [15] undergoing any other painful suffering, we share mentally in his pain? Is it because nature is common to us all, and it is this which shares in the sufferer’s pain, when we see any of these things happening to him, through kinship with him? Or is it because, just as the nose and hearing according to their particular faculties receive certain emanations, so also the sight does the same as the result of things pleasant [20] and painful?
8 · Why is it that those who come into contact with phthisis or ophthalmia or scurvy become affected by them, but there is no contagion from dropsy or fevers or apoplexy and the rest? In ophthalmia is contagion due to the fact that the eye is very easily affected and more than the other senses assimilates itself to that which it [25] sees—for example, it moves when it sees something else moved—and so it very readily becomes disordered when it sees another eye in that condition? In phthisis is the contagion due to the fact that phthisis makes the breath weak and laboured, and those diseases are most quickly contracted which are due to the corruption of the breath, as is seen in plagues? He therefore who comes into contact with the sufferer [30] inhales this corrupted breath, and so himself becomes ill, because the breath is unhealthy; and he catches the disease from one person only, because that person exhales this particular breath, which is different from that which others exhale; and he catches the same disease, because, in inhaling the breath by which he becomes infected, he is inhaling just such breath as he would if he were already suffering from the disease. Scurvy is more catching than the other diseases, such as leprosy and the like, because it affects the surface of the body and causes a glutinous discharge (for this is the nature of itching diseases), and so this disease, being on the [35] surface of the body and glutinous, can be conveyed by contact. Other similar diseases are not so conveyed, because either they are not on the surface, or else, being on the surface, they do not remain there, because they are dry.
9 · Why do purslane and salt stop inflammation of the gums? Is it because [887b1] purslane contains some moisture? This is seen to be so if one chews it or if it be crushed together1 for some time; for the moisture is then drawn out of it. The glutinous matter sinks into the gum and draws out the acidity. For that there is an affinity between the disease and the remedy is shown by the acidity; for the juice of [5] the purslane has a certain acidity. Salt, on the other hand, dissolves and draws out the acidity. Why then do lye and soda not have this effect? Is it because they have an astringent instead of a dissolvent effect?
BOOK VIII
PROBLEMS CONNECTED WITH CHILL AND SHIVERING
[10] 1 · Why is it that those who are chilled become livid? Is it because the blood is congealed by the cold and, as it congeals, becomes black through the absence of heat? (A white colour, on the other hand, is to be attributed to fire.) For this reason also the flesh of the aged is particularly livid, because
it contains very little heat.
[15] 2 · Why is it that those who are chilled cannot sleep? Is it because any one who is chilled tends to hold his breath, but a sleeper exhales rather than inhales, so that it is difficult for one who is cold to sleep, since it is impossible to do contrary things simultaneously?
[20] 3 · Why is it that those who are ill or in pain or angry become more active under the influence of cold? Is it because a cold condition makes a man stronger?
4 · Why is it that athletes in good training do not bear the cold well? Is it because their condition is clean and airy and free from fat? Such a condition is easily accessible to the air, since it is permeable and does not contain any heat; fat, [25] on the other hand, is hot, unless it is saturated with moisture.
5 · Why are the extremities most affected by cold? Is it due to their narrow shape? Also the ducts in them, being narrow, hold little blood, and therefore little heat; for the blood is hot.
6 · Why are the feet more liable to become chilled when they are suspended [30] in mid air? Is it because the wind blows more underneath then? Or is it because the blood is contracted into a narrower space below, and so the rest of the foot is more easily chilled, because the heat leaves it?