Comte’s most interesting and fertile leading idea is that the sciences conceived in this way are still in their infancy and do not deserve their name. Those who take them up should, in the first place, convince themselves of the fact that they prove no more in favour of spiritualism or materialism, of protection or of free exchange, than physics or chemistry prove in favour of the unity or the plurality of substances in the universe. In the school of the more advanced sciences men may be taught to distinguish between the objects of positive research and the metaphysical or practical questions. They will see also that the human mind did not begin by making this distinction in the case of inorganic and of living nature. For a long time it could only think of physical phenomena religiously. Without the admirable effort of the Greek men of science and philosophers, we might yet find ourselves in this period, and positive philosophy might still be awaiting the hour of its birth. To-day this philosophy has come into being. In order to prove finally established, it requires that individual and social human nature should become the object of a science as disinterested as physics and biology have already become. From that day alone will the “Social sciences” be definitely constituted. It is true that since in a certain way the object of these sciences is ourselves, it seems paradoxical to look upon them in the same way as if it were a question of salts or of crystals. We persist in believing that any knowledge of this order, as soon as it is acquired, admits of immediate applications to our condition or conduct. But this is an illusion. Is not the importance of the “_milieu_” in which we find ourselves, and of the forces which affect us from without for our welfare and even for our preservation which depends upon them at every moment, a simple matter of evidence? Nevertheless, we seek a purely abstract, scientific knowledge of the laws of phenomena, because we know that our effective power upon natural forces is subordinate to science. In the same way we separate physiology from therapeutics and medicine, and we especially await the progress of these from physiology. So in the same way, pædagogy, rational economy, politics, and in general all the social arts in the future will be subordinated to the theoretical science of the individual and social nature of man, when this science has been constituted by means of a purely positive method, and is no longer expected to “prove” anything but its laws.