In advancing this latter hypothesis, Wallace declares that it no more impairs the theory of natural selection than the latter is weakened by the fact of artificial selection. Few, I think, will accept this proposition. The chief apology for Darwinism in the eyes of men of science, its great charm to all its partisans, lies in the pretensions which it puts forward of connecting organic origins, those of man as well as those of plants, with the single action of second causes; and to explain the present state of living beings by physical and physiological laws, just as geology and astronomy explain the present state of the material world entirely by the general laws of matter. In making the intervention of an _intelligent will_ necessary for the realisation of the human being, Wallace has set himself in opposition to the very essence of the theory. Such is the opinion of most Darwinists, who have treated him somewhat as a deserter. I am not therefore called upon to examine this latter hypothesis of Wallace. I am, however, at liberty to state that most of the facts, which have induced one of the founders of Darwinism to separate from his chief upon so important a point, retain all their value as objections. The mistake of Wallace consists in failing to see that his statements upon the subject of man apply equally to animals, and Claparède has justly reproached him with a want of logic on this point. He has been less happy in the answers which he has made to his old ally. Doubtless, he who regards the question exclusively from a Darwinian point of view, and accepts as true everything which I have endeavoured to shew to be false, will readily find a solution for many of the difficulties raised by Wallace. But his statements upon _latent aptitudes_, upon the superior faculties of the human mind, and upon the moral sense, are very difficult to refute. Claparède has only alluded to the former. Darwin has attempted to go further; but his theories and hypotheses upon these important questions do not appear to me to have given much satisfaction to the most devoted of his followers. I cannot here enter into a discussion, which, to have any value, should be carried to some length, and I refer the reader to the work upon the _Descent of Man_, and to my articles in the Journal des Savants.