Man has to live by values, a fact brought out with a sort of dogged repetition by Tolstoi. To live is to value, no matter what else it may be. So Tolstoi rightly claimed, and he also said that to live as man is to rate things up and down, as good and as evil. It is to know, and to use a measuring rod which we often call a norm or standard. Tolstoi said that we do not know at all what life would be like without this constant valuing and rating of acts and things. If that is so, man is the more or less consciously valuing animal, and the materials for a philosophy of value are at least as old as mankind, though this philosophy becomes evident only in men such as Plato and Aristotle, Augustine, Aquinas and Kant.