Positivism was a system. Agnosticism was at least a phase of thought. The broadening of the conception of science and the invasion of every area of life by a science thus broadly conceived, has been an influence less tangible than those others but not, therefore, less effective. Positivism was bitterly hostile to Christianity, though, in the mind of Comte himself and of a few others, it produced a curious substitute, possessing many of the marks of Roman Catholicism. The name 'agnostic' was so loosely used that one must say that the contention was hostile to religion in the minds of some and not of others. The new movement for an inclusive science is not hostile to religion. Yet it will transform current conceptions of religion as those others never did. In proportion as it is scientific, it cannot be hostile. It may at most be indifferent. Nevertheless, in the long run, few will choose the theme of religion for the scientific labour of life who have not some interest in religion. Men of these three classes have accepted the doctrine of evolution. Comte thought he had discovered it. Spencer and those for whom we have taken him as type, did service in the elaboration of it. To the men of our third group, the truth of evolution seems no longer debatable. Here too, in the word 'evolution,' we have a term which has been used with laxity. It corresponds to a notion which has only gradually been evolved. Its implications were at first by no means understood. It was associated with a mechanical view of the universe which was diametrically opposed to its truth. Still, there could not be a doubt that the doctrine contravened those ideas as to the origin of the world, and more particularly of man, of the relations of species, and especially of the human species to other forms of animal life, which had immemorially prevailed in Christian circles and which had the witness of the Scriptures on their behalf. If we were to attempt, with acknowledged latitude, to name a book whose import might be said to be cardinal for the whole movement treated of in this chapter, that book would be Darwin's _Origin of Species_, which was published in 1859.