We have already seen that these relations are extremely close. On the one hand, sociology could not be constituted so long as higher biology had not reached a certain degree of development. History has furnished us with a proof of this: the state of infancy of biology contributed largely to the failure of Montesquieu’s and Condorcet’s sociological attempts. But, on the other hand, the study of the intellectual and moral functions, that is to say, the highest part of biology, can only be made from the sociological point of view. Here we have a kind of mixed domain, which properly belongs neither to the one nor to the other of the sciences. Could we not then consider sociology as a simple extension of biology, an extension which would be far more important in the case of the human species than in any of the others? Do we not do this implicitly when we attribute the study of the intellectual and moral functions to biology, since everything which bears the name of “moral science,” history, law, political economy, etc., finally rests upon these functions? What is the use of a new fundamental science for the study of phenomena which at bottom reduce themselves to biological phenomena? Comte protested against this interpretation of his doctrine.[235] According to him, sociology is no less irreducible to biology, than the latter is to chemistry. The sociological phenomena, independently of the more general laws which are common to them with the subjacent orders, have laws of their own which regulate them. If animal societies only existed as we see them to-day, it would perhaps not be impossible to consider sociology as an appendix of biology. But human society excludes any attempt of this kind. For it is social life which has made the extraordinary development of the intellectual and moral functions possible in man, and this development is the very definition of humanity. Now, the first consequence of this development is that biology properly so-called, no longer suffices for studying it. We need a new method in it, the method of historical observation. Already, were it for this reason alone, there can be no question of reducing sociology to biology. In the second place, when we pass from the individual to the collective organism, “the continued expansion and the almost indefinite perpetuity” of the latter makes it almost impossible not to separate it from the former in a scientific study.[236] Comte is not deceived by the analogy between the two kinds of organism. To speak accurately, sociology with him, hardly ever considers anything except a single organism. Let us leave aside the little that it says of animal societies. It represents the human race as constituting, in time and in space, “an immense and eternal social unity, whose various organs, individuals and nations, united by universal solidarity, each, according to a determined manner and degree concur in the evolution of Humanity.”