then is the one above deduced from it--that humanity must in the end become completely adapted to its conditions-- unquestionable also. Progress, therefore, is not an accident, but a necessity. Instead of civilization being artificial, it is a part of nature; all of a piece with the development of the embryo or the unfolding of a flower. The modifications mankind have undergone, and are still undergoing, result from a law underlying the whole organic creation; and provided the human race continues, and the constitution of things remains the same, those modifications must end in completeness. As surely as the tree becomes bulky when it stands alone, and slender if one of a group; as surely as the same creature assumes the different forms of cart-horse and racehorse, according as its habits demand strength or speed; as surely as a blacksmith's arm grows large, and the skin of a labourer's hand thick; as surely as the eye tends to become long-sighted in the sailor, and shortsighted in the student; as surely as the blind attain a more delicate sense of touch; as surely as a clerk acquires rapidity in writing and calculation; as surely as the musician learns to detect an error of a semitone amidst what seems to others a very babel of sounds; as surely as a passion grows by indulgence and diminishes when restrained; as surely as a disregarded conscience becomes inert, and one that is obeyed active; as surely as there is any efficacy in educational culture, or any meaning in such terms as habit, custom, practice; so surely must the human faculties be moulded into complete fitness for the social state; so surely must the things we call evil and immorality disappear; so surely must man become perfect." Social Statics, stereotyped ed. 1868, p. 78 f. {51}