Auguste Comte disliked and despised Plato, altogether preferring Aristotle to him as a philosopher; but it is fundamentally as a Platonist, not as an Aristotelian, that he should himself be classed--in this sense, that he valued knowledge above all as the means towards reconstituting society on the basis of an ideal life. And this is the first reason why his philosophy is called positive--to distinguish it as reconstructive from the purely negative thought of the Revolution. The second reason is to distinguish it as dealing with real facts from the figments of theology and the abstractions of metaphysics. Positive science explains natural events neither by the intervention of supernatural beings nor by the mutual relations of hypostasised concepts, but by verifiable laws of succession and resemblance. Turgot was the first to distinguish the theological, metaphysical, and mechanical interpretations as successive stages of a historical evolution (1750); Hume was the first to single out the relations of orderly succession and resemblance as the essential elements of real knowledge (1739); Comte, with the synthetic genius of the nineteenth century, first combined these isolated suggestions with a wealth of other ideas into a vast theory of human progress set out in the fifth and sixth volumes of his _Philosophie Positive_--the best sketch of universal history ever written. The positive sciences fall into two great divisions--the concrete, dealing with the actual phenomena as presented in space and time; the abstract, which alone concern philosophy, dealing with their laws. The most important of the abstract sciences is Sociology, claimed by Comte as his own special creation. The study of this demands a previous knowledge of biology, psychology {130} being dismissed as a metaphysical delusion and phrenology put in its place. The science of life presupposes Chemistry, before which comes Physics, presupposing Astronomy, and, as the basis of all, Mathematics, divided into the calculus and geometry. At a later period Morality was placed as a seventh fundamental science at the head of the whole hierarchy.