is this: Every active force produces more than one change—every cause produces more than one effect.[3]

In the first part of the Essay many and varied facts are adduced to show that every kind of progress is from the simple to the complex. The aim of the second part is to show why this is so: it is 'because each change is followed by many changes'. From the beginning, the decomposition of every expended force into several forces has been perpetually producing a higher complication, and thus Progress is not an accident but a beneficent necessity. In a brief third part we are bidden to remember that

'after all that has been said the ultimate mystery remains just as it was. The explanation of that which is explicable does but bring out into greater clearness the inexplicableness of that which remains behind.... The sincere man of science, content to follow wherever the evidence leads him becomes by each new enquiry more profoundly convinced that the Universe is an insoluble problem.... In all directions his investigations bring him face to face with the unknowable; and he ever more clearly perceives it to be the unknowable'.[4]

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, were not accepted by a newer generation of thinkers. Still, to have taken a definite and, for all his detractors may say, an honoured position in the line of those who make history in the philosophy of life and mind—that could never be taken away from him.

It will perhaps be said that this emphasis on the philosophy of life and mind does scant justice to the range and sweep of Spencer's philosophy as a whole; and no doubt others will contend that the emphasis should be laid elsewhere; on the mechanical foundations; on evolution as a universal principle. It will be urged that Spencer widened to men's view the scope of scientific explanation. He proclaimed 'the gradual growth of all things by natural processes out of natural antecedents'.[10] Even in the Nonconformist letters 'there is', he himself says,[11] 'definitely expressed a belief in the universality of law—law in the realm of mind as in that of matter—law throughout the life of society as throughout the individual life. So, too, is it with the correlative idea of universal causation.' And if there be law it must at bottom be one law. Thus in First Principles Spencer propounded a sweeping and sonorous formula, which every disciple knows by heart, embodying the fundamental traits of that unceasing redistribution of matter and motion which characterizes evolution as contrasted with dissolution. Was it not this that he himself regarded as his main contribution to philosophy? Did he not himself provide a summary, setting forth the sixteen articles of the Spencerian creed; and is not this summary given a prominent position in the Preface he wrote to Howard Collins's Epitome of the Synthetic Philosophy? Do not these fundamental articles of his faith deal with ubiquitous causes, with the instability of the homogeneous and the multiplication of effects, with segregation and equilibration, and with the basal conception of the persistence of force? There is here, it may be said, no special reference to the organic and the superorganic. And why? Just because Spencer's interpretation is all-inclusive; because biology,