The supreme requirement of our intellect is unity. Shall we ever reach this unity by using the objective method in the sciences? Evidently not. Even in each order of phenomena separately considered we do not see how to reduce the laws which we know to a single law of a more general character. And what are the laws known to us compared with those which elude our search, and which perhaps may do so for ever? Considered in its object, each one of our sciences reaches, so to speak, to infinity, far beyond our limited horizon. If then, in order to satisfy us, a _single_ conception of the world is necessary, we shall never obtain such a conception from the objective point of view. But if we change our point of view, if we refer the whole of the sciences to man, or better, to humanity, as a centre, we shall then be able to realise the unity which we seek. This is precisely what is made possible by sociology, by subordinating the hierarchy of the positive sciences to the final science of humanity. To consider the other fundamental sciences as “indispensable preliminaries,”[99] to represent the evolution which has brought them forth in turn as the very history of human progress; to verify the law of the three states in all our beliefs, and in all our knowledge; finally, to control all scientific research from the sociological point of view: this is what Comte understands by the conciliation of the two methods. The whole development of positive science from mathematics to sociology, lies between the new use which is made of subjective method and that which was spontaneously made of it by theological philosophy. When theological philosophy considered the knowledge of man and that of the world as interdependent, the instinct which animated it was a just one. But it was imagining instead of observing. It represented the world as filled with “causes” analogous to the will of man and equally capricious. The new subjective method rests, on the contrary, upon the very results of the positive sciences, brought to a synthesis in sociology. It takes as established that the intellectual and moral phenomena depend upon the biological laws, and that the biological laws themselves are subordinate to the laws of the inorganic _milieu_. But, since the “final systematisation of all these laws”[100] must always remain impossible from the objective point of view, the new subjective method undertakes it from the point of view of humanity as a centre.