Timaeus

​Timaeus: But if it flows in more abundantly, overcoming the fibers by its own heat and shaking them by boiling them into disorder; and if it becomes sufficient to retain its mastery to the end, penetrating to the race of the marrow and burning it, it unties from there the moorings of the soul, like those of a ship, and lets her go free. But when it is less, and the body, though melting, resists, it is itself overcome and either is cast out throughout the whole body, or, being forced through the veins into the lower or the upper belly, like a fugitive from a city in mutiny, escaping from the body, it produces diarrheas, dysenteries, and all such diseases. Now, the body that is diseased chiefly from an excess of fire produces continuous heat and fevers; that from air, quotidian fevers; that from water, tertian fevers, because water is more sluggish than air and fire; while that from earth, which is the fourth and most sluggish of these, being purified in fourfold periods of time, produces quartan fevers and is with difficulty rid of. And the diseases concerning the body happen to arise in this way, but those concerning the soul owing to the condition of the body in the following way. Indeed, we must agree that the disease of the soul is folly, and that there are two kinds of folly, the one madness and the other ignorance. Therefore, whatever affection a man suffers that causes him to have either of these, we must call it a disease, and we must posit that excessive pleasures and pains are the greatest of diseases for the soul. For when a man is overjoyed, or on the contrary suffering from pain, hastening to seize the one unseasonably and to avoid the other, he is unable either to see or to hear anything aright, but is in a frenzy and is at that moment least of all capable of participating in reason. And as for the man in whom the seed about the marrow becomes abundant and fluid, and who is like a tree naturally more fruitful than is symmetrical, acquiring many pains on each occasion and many pleasures in his desires and in the offspring concerning such things, and being for the most part of his life in madness because of the greatest pleasures and pains, having his soul diseased and foolish owing to his body, he is thought to be not diseased but voluntarily evil. But the truth is that incontinence in sexual pleasures has become, for the most part, a disease of the soul, due to the condition of a single class of substance which, because of the porosity of the bones, is fluid and makes the body wet. And indeed, almost all those things said about incontinence in pleasures and the reproach against them as though men were voluntarily evil, are not rightly reproached. For no one is voluntarily evil, but the evil man becomes evil because of some bad condition of the body and an uneducated rearing; and to everyone these things are hostile and happen against his will. And again, as regards pains, the soul in the same way, because of the body, acquires much evil.