Among the ancients Aristotle is the only thinker who furnishes us with a fully developed philosophical conception of man's relationship to the world about him, and then uses this conception as a basis for the determination of man's life in relationship with nature. Part of this philosophy finds its source in certain conceptions reigning among the ancient Greeks, ideas which he as a product of ancient life and civilization most naturally accepted; but another part of it, and a significant part too, is the result of Aristotle's own insight into human life and its meaning. In such studies we must remember that Aristotle was very critical of much in the Greek city-state; and, as a Macedonian he was more sympathetic with an agrarian economy than with the Ionian city economy. We can never understand Aristotle if we take him to be an Athenian, and assume that his sympathies were with Athenian mercantile democracy. He is not bound down to any one ancient economy and has a critical attitude towards all of them. What he has in mind are certain norms or ideals for human life and its relationship to nature, and on these he bases his whole system of social and economic thought and thus throws light upon the systems of social and economic life historically developed.