Littré makes a fair division of credit among others as well as those already named, and concludes as follows: “Turgot had discovered that human conceptions, at first theological, afterwards become metaphysical and end by being positive. Kant had known that history is a natural phenomenon, subjected to a determinate course, and Condorcet, pushed harder than his predecessors by advancing time,” (he had been condemned to death) “had attempted to trace a table that should put in evidence the enchainment of the progresses of civilisation. These are great things, but they are still only rudiments; for neither Turgot nor his successors make use of the discovered law to found upon this general fact evolution; Kant, who perceives clearly the necessity of conceiving history as regulated by the conditions inherent to humanity, is unable to base this important notion on anything better than an _à priori_ idea” (the metaphysical principle that nature does nothing in vain, and that as human faculties do not reach their development in the individual, who is ephemeral, they must do so in the species, which is durable) “and thus he leaves it incapable of fixing the attention of a century whose tendencies were more and more positive; lastly Condorcet has no other guide than the negative philosophy of the eighteenth century in a work to which it could bring only contradiction.” John Stuart Mill says of Comte that “far from pretending to originality when he had really no right to do so, he was eager to attach his most original thoughts to every germ of a similar idea that he met with among his predecessors.” Speaking for himself, Littré says of the law of the three stages, “I do not reject it, I restrain it. As long as we remain in the scientific order and consider the conception of the world first theological, then metaphysical, finally positive, the law of the three stages has its full efficacy in directing the speculations of history.... But in history all is not comprised in the scientific order. M. Comte, who has said somewhere that it is necessary to suppose, at the beginning of humanity, certain notions that were neither theological nor metaphysical, has indicated the germ, I will not say of my objection, but of my restriction. In fact this law of the three stages comprehends neither industrial, nor moral, nor æsthetic development. It has however, the excellent character of being relative to the speculations in which evolution by filiation is most manifest and consequently of giving a positive notion of the march of history.”