if it were the definite expression of some true physical and efficient cause, to which he only claims to add some subsidiary help from another physical cause which is wholly separate. But if natural selection is a mere phrase, vague enough and wide enough to cover any number of the physical causes concerned in ordinary generation, then the whole of Mr. Spencer's laborious argument in favor of his "other factor" becomes an argument worse than superfluous. It is wholly fallacious in assuming that this "factor" and "natural selection" are at all exclusive of, or even separate from, each other. The factor thus assumed to be new is simply one of the subordinate cases of heredity. But heredity is the central idea of natural selection. Therefore natural selection includes and covers all the causes which can possibly operate through inheritance. There is thus no difficulty whatever in referring it to the same one factor whose solitary dominion Mr. Spencer has plucked up courage to dispute. He will never succeed in shaking its dictatorship by such a small rebellion. His little contention is like some bit of Bumbledom setting up for Home Rule—some parochial vestry claiming independence of a universal empire. It pretends to set up for itself in some fragment of an idea. But here is not even a fragment to boast of or to stand up for. His new factor in organic evolution has neither independence nor novelty. Mr. Spencer is able to quote himself as having mentioned it in his "Principles of Biology" published some twenty years ago; and by a careful ransacking of Darwin he shows that the idea was familiar to and admitted by him at least in his last edition of the "Origin of Species." Mr. Spencer insists that this fact is evidence of a "reaction" in Darwin's mind against the sole factorship of natural selection. Darwin was a man so much wiser than all his followers, and there are in his book so many indications of his sense of our great ignorance, that most probably he did grow in the consciousness of the necessary incompleteness and shortcomings of his own explanations. But there was nothing whatever to startle him in the idea of heredity propagating structural change, through functional use and disuse. This idea was not incongruous with his own more general conception. On the contrary, it was strictly congruous and harmoniously subordinate. He did not profess to account for all the varieties which emerge in organic forms. Provisionally, and merely for the convenience of leaving that subject open, he spoke of them as fortuitous. But to assume the really fortuitous or accidental character of variation to be an essential part of this theory, is merely one of the many follies and fanaticisms of his followers.
Although, therefore, the particular case chosen by Mr. Herbert Spencer to illustrate the incompetency of natural selection.
