The favourite medico-moral formula (whose originator was Ariston of Chios), "Virtue is the health of the soul," would, for all practical purposes, have to be altered to this: "Thy virtue is the health of your soul." For there is no such thing as health in itself, and all attempts to define a thing in that way have lamentably failed. It is necessary to know your aim, your horizon, your powers, your impulses, your errors, and especially the ideals and fantasies of your soul, in order to determine what health implies even for your body. There are consequently innumerable kinds of physical health; and the more one again permits the unique and unparalleled to raise its head, the more one unlearns the dogma of the "Equality of men," so much the more also must the conception of a normal health, together with a normal diet and a normal course of disease, be abrogated by our physicians. And then only would it be time to turn our thoughts to the health and disease of the sout, and make the special virtue of everyone consist in its health; but, to be sure, what appeared as health in one person might appear as the contrary of health in another. In the end the great question might still remain open: Whether we could do without sickness for the development of our virtue, and whether our thirst for knowledge and self-knowledge would not especially need the sickly soul as well as the sound one; in short, whether the mere will to health is not a prejudice, a cowardice, and perhaps an instance of the subtlest barbarism and unprogressiveness?