Herbert Spencer is a philosopher of a wider range. A believer in organic evolution before Darwin published his epoch-making work, he accepted at once Darwin's useful idea, and incorporated it as a minor part in its fitting place in his own system. But that system itself, alike in its conception and its inception, was both independent of and anterior to Darwin's first pronouncement. It certainly covered a vast world of thought which Darwin never even attempted to enter. To Herbert Spencer, Darwin was even as Kant, Laplace, and Lyell - a laborer in the special field who produced results which fell at once into their proper order in his wider synthesis. As sculptors, they carved out shapely stones, from which he, as architect, built his majestic fabric. The total philosophic concept of evolution as a cosmical process - one and continuous, from nebula to man, from star to soul, from atom to society - we owe to Herbert Spencer himself, and to him alone, using as material the final results of innumerable preceding workers and thinkers...

May I begin with a passage which I quoted from one of Mr. Spencer's own early works no less than eleven years since, in my little monograph on Charles Darwin? It occurs in an essay on The Development Hypothesis, in that long-defunct paper, the Leader. 
"Even could the supporters of the development hypothesis merely show that the origination of species by the process of modification is conceivable, they would be in a better position than their opponents. But they can do much more than this. They can show that the process of modification has effected, and is effecting, great changes in all organisms, subject to modifying influences... They can show that any existing species - animal or vegetable - when placed under conditions different from its previous ones, immediately begins to undergo certain changes of structure fitting it for the new conditions. They can show that in successive generations these changes continue, until ultimately the new conditions become the natural ones. They can show that in cultivated plants, in domesticated animals, and in the several races of men, these changes have uniformly taken place. They can show that the degrees of difference, so produced, are often, as in dogs, greater than those on which distinctions of species are in other cases founded. They can show that it is a matter of dispute whether some of those modified forms are varieties or modified species. They can show too that the changes daily taking place in ourselves - the facility that attends long practice, and the loss of aptitude that begins when practice ceases - the development of every faculty, bodily, moral, or intellectual, according to the use made of it, are all explicable on this same principle. And thus they can show that throughout all organic Nature there is at work a modifying influence of the kind they assign as the cause of these specific differences, an influence which, though slow in its action, does, in time, if the circumstances demand it, produce marked changes; an influence which, to all appearance, would produce in the millions of years, and under the great varieties of conditions which geological records imply, any amount of change." 
Now, by most readers at the present day, this passage would undoubtedly be at once set down as "Darwinian." But when was it written?...

Ses oeuvres