No one complains more loudly of this comparative failure than some of the most distinguished students of social science themselves. Professor Marshall, for instance, who has done more than any other English author to breathe into technical economics the spirit of evolutionary science, admits that Comte, who laid the foundation of sociology, and Mr. Spencer, who has invested it with a definitely scientific character, have brought to the study of “_man’s actions in society unsurpassed knowledge and great genius, and have made epochs in thought by their broad surveys and suggestive hints_”; but neither of them, he proceeds to say, has succeeded {11} in doing more than this. Mr. Kidd, again, whose work on _Social Evolution_, if not valuable for the conclusions he himself desires to substantiate, is curiously significant as an example of contemporary sociological reasoning, repeats Professor Marshall’s complaint, and gives yet more definite point to it. Having observed that “_despite the great advance which science has made in almost every other direction, there is, it must be confessed, no science of human society, properly so called_,” he justifies this observation by insisting on what is an undoubted fact, that “_so little practical light has even Mr. Herbert Spencer succeeded in throwing on the nature of the social problems of our time, that his investigations and conclusions are, according as they are dealt with by one side or the other, held to lead up to the opinions of the two diametrically opposite camps of individualists and collectivists, into which society is rapidly becoming organised_.” Now what is the reason of this? Here is the question that confronts us. That the methods adopted by the scientist in the domain of physics are applicable to social phenomena, just as they are to physical, has been not only established in a broad and general way, but demonstrated by a mass of minute and elaborately co-ordinated facts. Why, then, when we find them in the sphere of physics solving one problem after another with a truly surprising accuracy, do they yield us such vague and often contradictory results when we apply them to the solution of the practical problems of society? {12}