This distinction between the speculative and practical aspects of social science has a special importance, which will be explained and insisted on presently. But it is here mentioned only to show the reader how strong a combination of motives is impelling the present generation—the conservative classes and the revolutionary classes equally—to transfer to social science the interest once felt in physical; and how strong is the stimulus thus applied to sociologists to emulate the diligence and success of the physicists and biologists, their predecessors. Nor have diligence, enthusiasm, or scientific genius been wanting to them. As has already been observed, they have transformed social science altogether by applying to it the doctrines of evolution which physical science taught them, and have thus organically affiliated the former study to the latter. This is in itself a triumph worthy of the enterprise that has achieved it. But they have done far more than borrow from physics this mere general theory. They have established between physical phenomena and social an enormous number of analogies, so close that the one set assists in the interpretation of the other. They have borrowed from the physicists a number of their subsidiary theories, their methods of grouping facts, and, above {10} all, their methods of studying them. In a word, they are endeavouring to follow the masters of physical science along the precise path which has led the latter to such solid and such definite results. We have now, however, to record a singular and disappointing truth. Though men of science have, in the manner just described, been engaged for years in the field of sociological study; though the way was prepared for them by men like Comte, Mill, and Buckle; though amongst them have been men like Mr. Spencer, with capacities of the highest order, and though certain results have been reached of the kind desired, complaints are heard from thinkers of all shades of opinion that these results are singularly unsatisfactory and inconclusive when compared with the efforts that have been made in reaching them, and still more when compared with the results of corresponding efforts in the sphere of physics.