If we venture into more ancient history, Plato's threefold division of the human soul into a rational element, a spirited active one, and an appetitive one, aiming at increase or gain, is immensely illuminating. As is well known, Plato said that society is the human soul writ large. In society he found three classes: the philosophic and scientific, the soldier-citizenry, and the traders and artisans. Hence the generalization as to the three dominating forces in human nature. Read the other way around, we perceive that trade in his days appealed especially to concupiscence, citizenship to a generous _élan_ of self-forgetting loyalty, and scientific study to a disinterested love of wisdom that seemed to be monopolized by a small isolated group. The distinctions were not in truth projected from the breast of the natural individual into society, but they were cultivated in classes of individuals by force of social custom and expectation. Now the prestige that once attached to the "instinct" of self-love has not wholly vanished. The case is still worth examination. In its "scientific" form, start was taken from an alleged instinct of self-preservation, characteristic of man as well as of other animals. From this seemingly innocuous assumption, a mythological psychology burgeoned. Animals, including man, certainly perform many acts whose consequence is to protect and preserve life. If their acts did not upon the whole have this tendency, neither the individual or the species would long endure. The acts that spring from life also in the main conserve life. Such is the undoubted fact. What does the statement amount to? Simply the truism that life is life, that life is a continuing activity as long as it is life at all. But the self-love school converted the fact that life tends to maintain life into a separate and special force which somehow lies back of life and accounts for its various acts. An animal exhibits in its life-activity a multitude of acts of breathing, digesting, secreting, excreting, attack, defense, search for food, etc., a multitude of specific responses to specific stimulations of the environment. But mythology comes in and attributes them all to a nisus for self-preservation. Thence it is but a step to the idea that all conscious acts are prompted by self-love. This premiss is then elaborated in ingenious schemes, often amusing when animated by a cynical knowledge of the "world," tedious when of a would-be logical nature, to prove that every act of man including his apparent generosities is a variation played on the theme of self-interest.