There is I think a growing consensus of opinion that the first of these three parts, subsequently expanded and illustrated with astonishing wealth of detail in the volumes of the _Synthetic Philosophy_, contains the germ of all that is best in the teaching of Herbert Spencer; and that it was amid phenomena which admitted of interpretation from the biological, or quasi-biological, point of view that he found his most congenial sphere of work and the one in which his method was most effectively employed. The story of evolution is the story of inter-related changes. In any organic whole there are certain salient features of the historical sequence.[5] The parts get more different from each other, and they also get more effectively connected with each other; the individual whole gets more different from its environment, and it also preserves and extends its connexion with the environment; the several individuals get more different from others, while their connexion with others is retained and new connexions are established. Nowadays these central ideas may seem familiar enough; but that is just because Spencer's thought has been so completely assimilated. And then we must remember that these main principles are supplemented by a great number of ancillary generalizations, many of which have been incorporated in the scientific doctrine which is current to-day. We must bear in mind that of the _Biology_ Charles Darwin wrote:[6] 'I am astonished at its prodigality of original thought.' Of the _Psychology_ William James says[7] that of the systematic treatises it will rank as the most original. These are the opinions of experts. No discussion of sociology or ethics is complete if it ignores Spencer's contributions to these subjects. The _Ethics_, says James[8] is a most vital and original piece of attitude-taking in the world of ideals. It was his firm and often inflexible 'attitude' which was a source of strength in Spencer, though it was the strength of rigidity rather than that of sinewy suppleness. This was part of a certain 'narrowness of intent and vastness of extent' which characterized his mental vision. He was so obsessed with the paramount importance of biological relationships that in his _Sociology_, his _Ethics_, his _Psychology_, he failed to do justice to, or even to realize the presence of, other and higher relationships--higher, that is, in the evolutionary scale. But it was his signal merit to work biological interpretation for all, and perhaps more than, it was worth. It was on these lines that he was led to find a clue to those social and political developments, the discussion of which, in the _Nonconformist_ of 1842, constituted the first step from the life of an engineer to that other kind of life which led to the elaboration of the _Synthetic Philosophy_.[9] In his later years he was saddened to see that many of the social and political doctrines, for the establishment of which he had striven so strenuously,