In the sublime conception of the external universe and its present workings which we thus owe to the independent efforts of so many great progressive thinkers, and which has here been briefly and inadequately sketched out, Darwin's work in life falls naturally into its own place as the principal contribution to the evolutionary movement in the special biological department of thought. Within the more limited range of that department itself, the evolutionary impulse did not owe its origin to Charles Darwin personally; it took its rise with Erasmus Darwin, Buffon, and Lamarck, and it derived from our great modern English naturalist its final explanation and definitive proof alone. But just as the evolutionary movement in astronomy and cosmical thought is rightly associated in all our minds with the mighty theories of Kant, Laplace, and Herschel; just as the evolutionary movement in geology is rightly associated with the far lesser yet brilliant and effective personality of Lyell; just as the evolutionary movement in the derivative sciences is rightly associated with so many great still living thinkers; so the evolutionary movement in biology in particular rightly sums itself up in the honoured name of Charles Darwin. For what others suspected, he was the first to prove; where others speculated, he was the first to observe, to experiment, to demonstrate, and to convince.
It should be noted, too, that while to us who come after, the great complex evolutionary movement of the two last centuries justly reveals itself as one and indivisible, a single grand cosmical drama, having many acts and many scenes, but all alike inspired by one informing and pervading unity, yet to those whose half unconscious co-operation slowly built it up by episodes, piecemeal, each act and each scene unrolled itself separately as an end in itself, to be then and there attained and proved, quite apart from the conception of its analytic value as a part in a great harmonious natural poem of the constitution of things. Though evolution appears to us now as a single grand continuous process, a phase of the universe dependent upon a preponderating aggregation of matter and dissipation of energy, yet to Kant and Laplace it was the astronomical aspect alone that proved attractive, to Darwin it was the biological aspect alone, and to many of the modern workers in the minor fields it is the human and sociological aspect that almost monopolises the whole wide mental horizon. No greater proof can be given of the subjective distinctness of parts in what was objectively and fundamentally a single broad psychological revolution of the human mind, than the fact that Lyell himself, who more than any one man had introduced the evolutionary conception into the treatment of geology, should have stood out so long and fought so blindly against the evolutionary conception in the organic world. Indeed, it was not until the various scattered and many-coloured strands of evolutionary thought had been gathered together and woven into one by the vast catholic and synthetic intelligence of Herbert Spencer that the idea of evolution as a whole, as a single continuous cosmical process, began to be apprehended and gradually assimilated by the picked intelligences of the several distinct scientific departments.