Aristotle's Problems

...it withdraws the humor from the [stomach] for the necessity of digestion: and it is cooked there so late that they finish more slowly; for things which are dissolved by the vapor of water [are slower than] those by fire. Then, while it is ground more insistently, much wind is enveloped in it, which must first be consumed in the belly so that, at last, what remains of the meat, being now free, may be finished.

...concocted and exhaling on account of its quantity: being somewhat putrefied, it is of a foul odor.

Why do mustard and pepper and all acrid things, when applied to the skin, cause it to blister, yet when drunk do not at all harm the belly? Because they are transformed and digested before they can effect anything; and because the great moisture of the belly dissolves their acridity; otherwise, in an application upon the skin and its density, an occasion is provided for acrid things to take effect: and the skin is weak, whereas what is further inward possesses open pores and is more robust.

Why do those grieving and those rejoicing and laughing weep? Those grieving, because of the density of the pores in the eyes, squeeze out the moisture within them; for grief agitates the coldness and density of the pores. But those rejoicing, on the other hand, pour out moisture due to the rarity of the pores; however, in some with narrow pores of the eyes, tears are not produced in either case.

Why does paleness arise on the surface of the skin in those grieving? Because nature, together with the blood, penetrates inward, as we have said before, which was warming and thinning the surface.

Why is it common for those urinating to often emit a sound from both [outlets]? Since the bladder, full of urine, swells and narrows the rectum; presently, therefore, during the emptying, it provides an occasion for the exit of the spirit which is contained within the intestines. There are some who say the members are affected toward the excretion of the affection of a certain part.

Why do those looking at one yawning themselves yawn? Because nature is similarly affected by like things which exist in animals. And this is more intense in those devoid of reason. For thus, when one ass urinates, the others, being full of urine, also urinate together with it.

Why does one suffering from a disease of the eyes transmit the disease into the eyes of a healthy person, yet a healthy person does not transmit health to the sick one? Because the eyes are moist and soft and easily subject to diseases. Likewise, because health arises from a moderate temperament, while disease arises from an immoderate distemperament. Now, a moderate state is easily transmuted and turned by an immoderate one, as by its contrary. Is it not also that a certain immoderate disease of the eyes subverts health more quickly than it consists of a moderate temperament? Moreover, we know that a conversion occurs because of the natural parity and likeness of bodies.

Why do a coin and an apple appear larger in water than they are? Because the water joined to them receives the appearance of their color, which deceives, so that they seem larger; for this reason also the sun and moon and the other planets, when they reach the eastern or western horizon, are judged larger on account of the air which surrounds their bodies.

Why do quadrangular things at a distance seem round? Because since the sight cannot behold the angles from afar, as they are acute, it does not think it sees them; once these are removed by the deception of sight, the rest of the body appears round. It is clearly established that this happens by a deception of sight, just as an oar appears broken in water.

Why, when watching wood being cut from a distance, is the blow seen immediately, but the crash is heard a little later, though the blow and the crash happen at the same time? Because we have obtained sight as more subtle and swifter in its parts than hearing. Therefore, sight, being swifter, anticipates the blow in time; but hearing, being thicker in its parts, receives the blow later. By this reasoning, that also must be resolved: that in the clashing of clouds during a storm, when there is a twisted blow which is called thunder, and when those spirits catch fire they are named lightnings, as in the hurlings of fire and thunderbolts. First indeed we see the flash, and then later and a little more slowly we hear the thunder, although the stroke of the lightning occurs first or simultaneously with the thunder. Hence, therefore, sight, anticipating hearing as being of more subtle parts, sees the flash first. Thus, afterwards, hearing perceives the thunder, since it is thicker in its parts and consequently slow to receive.

Why, with the sight bare but the whole body covered in great cold, do we shiver in the body but not much in the face? Because of habituation. For the face is accustomed to be exposed to the air and perpetually joined to it; and so, since it is bare by custom, it has acquired a great bulwark against harsh incursions.

Why is yellow bile, remaining perpetually in the tunic which is called the choledochus (that is, the receiver of bile), most suitably accommodated to the body and does not consume it, yet when it comes to a tooth, a most hard body, it eats it away? For this reason, I say: because it seemed so to nature that it should inhabit that one body and for that very reason not destroy it. Since indeed a great medicine hindering disease is the name of nature. And I could offer no fewer infinite examples. In the womb, a ten-month-old infant remains for a short time without giving the pregnant woman any sense of weight; yet a light spirit coming into it excites pain, causing a sudden tension and intolerable heaviness. The windpipe is the receiver of spirit alone; but if cold or drink should rush into it, suffocation follows and a violent cough. For nature did not foresee this would happen; although in such a gathered and brief time, how could she have provided?

Why, of those who have entered the baths, when they come out washed, are some thirsty, but others not at all? Whosoever are drier and are moistened by the bath while thirsty, these are without thirst; for thirst comes from dryness; and especially since they are not resolved by the dry room; however, those who are more moist and without thirst, having stayed in air that is especially violently hot, and in a dry room, release their moisture through sweats and turn out thirsty.

Why do some of those who eat radishes belch something putrid, but others not? It must be said that...