All who, on attempting to speak or to write on medicine, have assumed for themselves a postulate as a basis for their discussion—heat, cold, moisture, dryness, or anything else that they may fancy—who narrow down the causal principle of diseases and of death among men, and make it the same in all cases, postulating one thing or two, all these obviously blunder in many points even of their statements,Or, reading καινοῖσι κτλ., of their novelties. but they are most open to censure because they blunder in what is an art, and one which all men use on the most important occasions, and give the greatest honours to the good craftsmen and practitioners in it. Some practitioners are poor, others very excellent; this would not be the case if an art of medicine did not exist at all, and had not been the subject of any research and discovery, but all would be equally inexperienced and unlearned therein, and the treatment of the sick would be in all respects haphazard. But it is not so; just as in all other arts the workers vary much in skill and in knowledge,Or manual skill and intelligence. so also is it in the case of medicine. Wherefore I have deemed that it has no need of an empty postulate,Or, reading χαινῆς, a novel postulate. But the writer’s objection is not that the postulate is novel, but that it is a postulate. A postulate, he says, is empty in a sphere where accurate and verifiable knowledge is possible. Only in regions where science cannot penetrate are ὑποθέσεις legitimate. For this reason I read κενῆς. as do insoluble mysteries, about which any exponent must use a postulate, for example, things in the sky or below the earth. If a man were to learn and declare the state of these, neither to the speaker himself nor to his audience would it be clear whether his statements were true or not. For there is no test the application of which would give certainty.

But medicine has long had all its means to hand, and has discovered both a principle and a method, through which the discoveries made during a long period are many and excellent, while full discovery will be made, if the inquirer be competent, conduct his researches with knowledge of the discoveries already made, and make them his starting-point. But anyone who, casting aside and rejecting all these means, attempts to conduct research in any other way or after another fashion, and asserts that he has found out anything, is and has been the victim of deception.Or, with the reading suggested, both deceives and is deceived. His assertion is impossible; the causes of its impossibility I will endeavour to expound by a statement and exposition of what the art is.Or, reading ὅτι ἔστιν, that the art really is an art, really exists. In this way it will be manifest that by any other means discoveries are impossible. But it is particularly necessary, in my opinion, for one who discusses this art to discuss things familiar to ordinary folk. For the subject of inquiry and discussion is simply and solely the sufferings of these same ordinary folk when they are sick or in pain. Now to learn by themselves how their own sufferings come about and cease, and the reasons why they get worse or better, is not an easy task for ordinary folk; but when these things have been discovered and are set forth by another, it is simple. For merely an effort of memory is required of each man when he listens to a statement of his experiences. But if you miss being understood by laymen, and fail to put your hearers in this condition, you will miss reality. Therefore for this reason also medicine has no need of any postulate.

For the art of medicine would never have been discovered to begin with, nor would any medical research have been conducted—for there would have been no need for medicine—if sick men had profited by the same mode of living and regimen as the food, drink and mode of living of men in health, and if there had been no other things for the sick better than these. But the fact is that sheer necessity has caused men to seek and to find medicine, because sick men did not, and do not, profit by the same regimen as do men in health. To trace the matter yet further back, I hold that not even the mode of living and nourishment enjoyed at the present time by men in health would have been discovered, had a man been satisfied with the same food and drink as satisfy an ox, a horse, and every animal save man, for example the products of the earth—fruits, wood and grass. For on these they are nourished, grow, and live without pain, having no need at all of any other kind of living. Yet I am of opinion that to begin with man also used this sort of nourishment. Our present ways of living have, I think, been discovered and elaborated during a long period of time. For many and terrible were the sufferings of men from strong and brutish living when they partook of crude foods, uncompounded and possessing great powersOr strong qualities.—the same in fact as men would suffer at the present day, falling into violent pains and diseases quickly followed by death. Formerly indeed they probably suffered less, because they were used to it, but they suffered severely even then. The majority naturally perished, having too weak a constitution, while the stronger resisted longer, just as at the present time some men easily deal with strong foods, while others do so only with many severe pains. For this reason the ancients too seem to me to have sought for nourishment that harmonised with their constitution, and to have discovered that which we use now. So from wheat, after steeping it, winnowing, grinding and sifting, kneading, baking, they produced bread, and from barley they produced cake. Experimenting with food they boiled or baked, after mixing, many other things, combining the strong and uncompounded with the weaker components so as to adapt all to the constitution and power of man, thinking that from foods which, being too strong, the human constitution cannot assimilate when eaten, will come pain, disease, and death, while from such as can be assimilated will come nourishment, growth and health. To this discovery and research what juster or more appropriate name could be given than medicine, seeing that it has been discovered with a view to the health, saving and nourishment of man, in the place of that mode of living from which came the pain, disease and death?

That it is not commonly considered an art is not unnatural, for it is inappropriate to call anyone an artist in a craft in which none are laymen, but all possess knowledge through being compelled to use it. Nevertheless the discovery was a great one, implying much investigation and art. At any rate even at the present day those who study gymnastics and athletic exercises are constantly making some fresh discovery by investigating on the same method what food and what drink are best assimilated and make a man grow stronger.

Let us consider also whether the acknowledged art of medicine, that was discovered for the treatment of the sick and has both a name and artists, has the same object as the other art,I.e. that of dieting in health. See Chapter VII. and what its origin was. In my opinion, as I said at the beginning, nobody would have even sought for medicine, if the same ways of life had suited both the sick and those in health. At any rate even at the present day such as do not use medical science, foreigners and some Greeks, live as do those in health, just as they please, and would neither forgo nor restrict the satisfaction of any of their desires. But those who sought for and discovered medicine, having the same intention as the men I discussed above, in the first place, I think, lessened the bulk of the foods, and, without altering their character, greatly diminished their quantity. But they found that this treatment was sufficient only occasionally, and although clearly beneficial with some patients, it was not so in all cases, as some were in such a condition that they could not assimilate even small quantities of food. As such patients were thought to need weaker nutriment, slops were invented by mixing with much water small quantities of strong foods, and by taking away from their strength by compounding and boiling. Those that were not able to assimilate them were refused even these slops, and were reduced to taking liquids, these moreover being so regulated in composition and quantity as to be moderate, and nothing was administered that was either more or less, or less compounded, than it ought to be.