more to the popular confusion of the subject than the notion that "Darwinism" and Evolution are the same thing. Mr. Darwin's fame rests chiefly upon the skill and perseverance with which he has worked out a single principle in its bearing upon the progressive diversity of organic life. The competitions of Nature leading to a struggle for existence, and that consequent winnowing which Mr. Darwin calls "Natural Selection," and Mr. Spencer calls "Survival of the Fittest," were recognized before Mr. Darwin's time: what he did, as I have before explained, was to show how this principle may aid in giving rise to new species from preexisting species. But this principle is secondary and derivative, and its operation may be traced, as Mr. Darwin has traced it, without going back to those primary forces, the resolution of which constitutes the radical problem of Evolution.
The principle which Mr. Darwin promulgated is a part of the great theory, and it has a philosophic importance, exactly in proportion to the validity of that larger system of doctrine to which it is tributary as an element. Not only has Mr. Darwin never taken up the question of Evolution from a scientific point of view, but it was not his aim to explain even the evolution of species in terms of ultimate principles, as a part of the universal transformation––that is, in terms of the redistribution of matter and motion; for it is in this way that all proximate principles, including Natural Selection, have to be expressed before the final interpretation is reached. This mode of dealing with the subject, the only thoroughly scientific method of its treatment, belongs to Mr. Spencer alone. As to his following Mr. Darwin, we have already seen that, two years before the "Origin of Species" was published, Mr. Spencer had reached the proof of Evolution as a universal law; had traced its dependence upon the principle of the Conservation of Force; had resolved it into its ultimate dynamical factors; had worked out many of its important features; had made it the basis of a system of Philosophy; and had shown that it furnishes a new starting-point for the scientific interpretation of human affairs.
Colonel Higginson imputes to Mr. Spencer, as a weakness, the propensity to write on a great number of subjects; I have shown, on the contrary, that he has been compelled to write upon many subjects from logical necessity, and has done so in unswerving devotion to the development of one class of ideas. It will be seen that he is now upon the same identical track of thought which he opened in his youth, to which he has consecrated his life, and which he has made his own. Thirty-two years ago he began to study the social condition and relations of men from the scientific point of view, and to treat of human society as a sphere of natural law. After eight years he published a treatise upon the question, which, although in advance of the times, only served to convince its author that the investigation was barely begun, and that, before any adequate social science was possible, the