For this reason the things that we have said are not to be looked upon as proofs but rather as indications of the dulness of those who think differently, and who do not even recognise what is agreed on by everyone and is a matter of daily observation. As for the scientific proofs of all this, they are to be drawn from these principles of which I have already spoken — namely, that bodies act upon and are acted upon by each other in virtue of the Warm, Cold, Moist and Dry. And if one is speaking of any activity, whether it be exercised by vein, liver, arteries, heart, alimentary canal, or any part, one will be inevitably compelled to acknowledge that this activity depends upon the way in which the four qualities are blended. Thus I should like to ask the Erasistrateans why it is that the stomach contracts upon the food, and why the veins generate blood. There is no use in recognizing the mere fact of contraction, without also knowing the cause; if we know this, we shall also be able to rectify the failures of function. “This is no concern of ours,” they say; “we do not occupy ourselves with such causes as these; they are outside the sphere of the practitioner, and belong to that of the scientific investigator.” Are you, then, going to oppose those who maintain that the cause of the function of every organ is a natural eucrasia, that the dyscrasia is itself known as a disease, and that it is certainly by this that the activity becomes impaired? Or, on the other hand, will you be convinced by the proofs which the ancient writers furnished? Or will you take a midway course between these two, neither perforce accepting these arguments as true nor contradicting them as false, but suddenly becoming sceptics — Pyrrhonists, in fact? But if you do this you will have to shelter yourselves behind the Empiricist teaching. For how are you going to be successful in treatment, if you do not understand the real essence of each disease? Why, then, did you not call yourselves Empiricists from the beginning? Why do you confuse us by announcing that you are investigating natural activities with a view to treatment? If the stomach is, in a particular case, unable to exercise its peristaltic and grinding functions, how are we going to bring it back to the normal if we do not know the cause of its disability? What I say is that we must cool the over-heated stomach and warm the warm the chilled one; so also we must moisten the one which has become dried up, and conversely; so, too, in combinations of these conditions; if the stomach becomes at the same time warmer and drier than normally, the first principle of treatment is at once to chill and moisten it; and if it become colder and moister, it must be warmed and dried; so also in other cases. But how on earth are the followers of Erasistratus going to act, confessing as they do that they make no sort of investigation into the cause of disease? For the fruit of the enquiry into activities is that by knowing the causes of the dyscrasiae one may bring them back to the normal, since it is of no use for the purposes of treatment merely to know what the activity of each organ is.

Now, it seems to me that Erasistratus is unaware of this fact also, that the actual disease is that condition of the body which, not accidentally, but primarily and of itself, impairs the normal function. How, then, is he going to diagnose or cure diseases if he is entirely ignorant of what they are, and of what kind and number? As regards the stomach, certainly, Erasistratus held that one should at least investigate how it digests the food. But why was not investigation also made as to the primary originative cause of this? And, as regards the veins and the blood, he omitted even to ask the question “how?”

Yet neither Hippocrates nor any of the other physicians or philosophers whom I mentioned a short while ago thought it right to omit this; they say that when the heat which exists naturally in every animal is well blended and moderately moist it generates blood; for this reason they also say that the blood is a virtually warm and moist humour, and similarly also that yellow bile is warm and dry, even though for the most part it appears moist. (For in them the apparently dry would seem to differ from the virtually dry.) Who does not know that brine and sea-water preserve meat and keep it uncorrupted, whilst all other water — the drinkable kind — readily spoils and rots it? And who does not know that when yellow bile is contained in large quantity in the stomach, we are troubled with an unquenchable thirst, and that when we vomit this up, we at once become much freer from thirst than if we had drunk very large quantities of fluid? Therefore this humour has been very properly termed warm, and also virtually dry. And, similarly, phlegm has been called cold and moist; for about this also clear proofs have been given by Hippocrates and the other Ancients.

Prodicus also, when in his book “On the Nature of Man” he gives the name “phlegm” to that element in the humours which has been burned or, as it were, over-roasted, while using a different terminology, still keeps to the fact just as the others do; this man’s innovations in nomenclature have also been amply done justice to by Plato. Thus, the white-coloured substance which everyone else calls phlegm, and which Prodicus calls blenna [mucus], is the well-known cold, moist humour which collects mostly in old people and in those who have been chilled in some way, and not even a lunatic could say that this was anything else than cold and moist.

If, then, there is a warm and moist humour, and another which is warm and dry, and yet another which is moist and cold, is there none which is virtually cold and dry? Is the fourth combination of temperaments, which exists in all other things, non-existent in the humours alone? No; the black bile is such a humour. This, according to intelligent physicians and philosophers, tends to be in excess, as regards seasons, mainly in the fall of the year, and, as regards ages, mainly after the prime of life. And, similarly, also they say that there are cold and dry modes of life, regions, constitutions, and diseases. Nature, they suppose, is not defective in this single combination; like the three other combinations, it extends everywhere.

At this point, also, I would gladly have been able to ask Erasistratus whether his “artistic” Nature has not constructed any organ for clearing away a humour such as this. For whilst there are two organs for the excretion of urine, and another of considerable size for that of yellow bile, does the humour which is more pernicious than these wander about persistently in the veins mingled with the blood? Yet Hippocrates says, “Dysentery is a fatal condition if it proceeds from black bile”; while that proceeding from yellow bile is by no means deadly, and most people recover from it; this proves how much more pernicious and acrid in its potentialities is black than yellow bile. Has Erasistratus, then, not read the book, “On the Nature of Man,” any more than any of the rest of Hippocrates’ writings, that he so carelessly passes over the consideration of the humours? Or, does the know it, and yet voluntarily neglect one of the finest studies in medicine? Thus he ought not to have said anything about the spleen, nor have stultified himself by holding that an artistic Nature would have prepared so large an organ for no purpose. As a matter of fact, not a matter of fact, not only Hippocrates and Plato — who are no less authorities on Nature than is Erasistratus — say that this viscus also is one of those which cleanse the blood, but there are thousands of the ancient physicians and philosophers as well who are in agreement with them. Now, all of these the high and mighty Erasistratus affected to despise, and he neither contradicted them nor even so much as mentioned their opinion. Hippocrates, indeed, says that the spleen wastes in those people in whom the body is in good condition, and all those physicians also who base themselves on experience agree with this. Again, in those cases in which the spleen is large and is increasing from internal suppuration, it destroys the body and fills it with evil humours; this again is agreed on, not only by Hippocrates, but also by Plato and many others, including the Empiric physicians. And the jaundice which occurs when the spleen is out of order is darker in colour, and the cicatrices of ulcers are dark. For, generally speaking, when the spleen is drawing the atrabiliary humour into itself to a less degree than is proper, the blood is unpurified, and the whole body takes on a bad colour. And when does it draw this in to a less degree than proper? Obviously, when it [the spleen] is in a bad condition. Thus, just as the kidneys, whose function it is to attract the urine, do this badly when they are out or order, so also the spleen, which has in itself a native power of attracting an atrabiliary quality,if it ever happens to be weak, must necessarily exercise this attraction badly, with the result that the blood becomes thicker and darker.

Now all these points, affording as they do the greatest help in the diagnosis and in the cure of disease were entirely passed over by Erasistratus, and he pretended to despise these great men — he who does not despise ordinary people, but always jealously attacks the most absurd doctr............