On the Nature of Man

​5. Now I said that, whatever things I should declare man to be, I would show them to be always the same both according to custom and according to nature. I declare them to be blood, phlegm, and yellow and black bile. And of these, I say first that their names are distinguished according to custom, and that none of them has the same name as another; next, that their forms are separated according to nature, and that phlegm is in no way like blood, nor blood like bile, nor bile like phlegm. For how could these be like one another, when neither their colors appear similar to those who look at them, nor do they seem similar to the touch of the hand? For they are not equally hot, nor cold, nor dry, nor wet. It is necessary then, since they differ so much from one another both in form and in power, that they are not one, unless fire and water are one and the same thing. And you would know by these things that all these are not one, but each of them has its own power and nature. For if you give to any man a medicine which draws phlegm, he will vomit phlegm for you; and if you give a medicine which draws bile, he will vomit bile for you. In the same way, black bile is purged if you give a medicine which draws black bile; and if you wound any part of his body so that a sore is made, blood will flow for him. And all these things will happen for you every day and night, both in winter and in summer, as long as he is able to draw the breath into himself and let it go again; and he will be able to do so until he is deprived of one of these innate elements. And these aforementioned things are innate; for how could they not be? First, it is clear that man has all these things in himself always as long as he lives; next, he has been born from a man having all these things, and has been nourished in a man having all these things, as many as I now declare and demonstrate.

​6. Those who say that man is one seem to me to adopt this opinion: seeing people drink medicines and perish in excessive purgings, some vomiting bile, others phlegm, they thought each of these things to be the man, whichever they saw him die purging. And those who say that blood is the man adopt the same opinion: seeing men slaughtered and blood flowing from the body, they think this is the soul for the man; and they all use these testimonies in their arguments. Yet, first of all, in excessive purgings no one has ever died having been purged of bile alone. But when someone drinks a medicine which vomits bile, he vomits first bile, then phlegm; and then, in addition to these, they vomit black bile under compulsion, and finally they also vomit pure blood. They suffer the same things also from medicines that draw phlegm; for first they vomit phlegm, then yellow bile, then black bile, and finally pure blood, and in this state they die. For the medicine, when it enters the body, draws first what is most according to its own nature of the things present in the body, and then it also drags and purges the others. For just as things that grow and are sown, when they come into the earth, draw each what is according to its own nature present in the earth—and there is in it acid, bitter, sweet, salty, and all kinds of things—first of all, then, it draws into itself the greatest amount of that which is most according to its nature, and then it also draws the others. And the medicines do something of this kind in the body: those which draw bile first purge the most unmixed bile, and then mixed; and again, the medicines for phlegm draw first the most unmixed phlegm, and then mixed; and for those who are slaughtered, first the blood flows warmest and reddest, and then it flows more phlegmatic and more bilious.