Ethics is not an abstract speculative science; it does not therefore belong to the hierarchy of the fundamental sciences. It is true that, at the end of his life, Comte added a seventh to the six sciences of the early list,[322] which precisely was ethics, that is to say the science of the laws which govern the emotions, passions, desires, etc., of man considered as an individual. But here it is more a question of ethical psychology than of ethics understood in the sense usual with philosophers. The latter, in Comte’s eyes, never constituted the object of a special science. As a matter of fact, either the laws of moral phenomena are studied, and this research, founded upon the positive knowledge of individual and collective human nature, forms a part of sociology. Or, starting from the knowledge of these laws, we ask ourselves what would be the best use for the power possessed by man of modifying phenomena; in this case it is an art whose rules must be determined. But for these rules to be rationally established, social science itself must be rationally founded. Thus, from the practical as from the speculative point of view, positive ethics depends upon sociology. I. In the XVIII. cent. Comte distinguishes three schools of Ethics: the utilitarian school, especially represented in his view by Helvetius; the Kantian School, which he knows through Cousin; and finally the philosophy of the moral sentiment; that is to say, the Scottish school; by none of the three is he fully satisfied. The Utilitarianism of Helvetius rests upon an inadequate psychology, which distorts human nature by denying against all evidence the existence of altruistic inclinations. He involuntarily tends to “reduce all the social relations to low coalitions of private interests.” The ethics of duty, as presented by Cousin, at any rate, organises “a kind of mystification, in which the so-called permanent disposition of each one to direct his conduct according to the abstract idea of duty would end in a small number of clever schemers taking advantage of the human race.” These remarks, in Comte’s mind address themselves less to the doctrine than to the person of Cousin. Finally the Scottish school was nearer to the truth than the others, since it admitted the existence of the altruistic tendencies beside the selfish ones. But it lacked precision and strength.