society, however broad may be its benevolence. It is this dissatisfaction with and revolt against the idea that the state is going comfortably forward, which are cardinal elements in the conception of the development of society; for without such dissatisfaction there could be no better society, but merely a lifeless continuation or equally lifeless extension of what is good.
II. There is another and perhaps more important thought, for which philosophy is indebted to the doctrine of evolution. Romanes writes: "That there is a general tendency for lower forms to yield their places to higher is shown by the gradual advance of organization throughout geological time."[1] Mr. Spencer, in summing up the operation of the primary laws of animal existence, affirms that "by virtue of them life has gradually evolved into higher forms."[2] And Darwin himself says, "All the chief laws of palaeontology plainly proclaim, as it seems to me, that species have been produced by ordinary generation, old forms having been supplanted by new and improved forms of life."[3] Common to those three extracts is the principle that lower types of living things slowly disappear, and higher types come into existence. Scientists distinguish between the fact of evolution and the cause of the fact; all or nearly all being agreed as to the general fact, but still at variance as to the cause. The disputants, whether they regard the cause as 'natural selection,' or 'survival of the fittest,' or 'the carrying out of an inherent purpose,' are unanimous in the opinion that changes in the structure of living beings are at least not the result of conscious effort on the part of the modified organisms. The individual animal is in some relation to a universal cause, call it nature or what you will; and only by understanding this cause is it possible to know the full meaning of even the most trifling variation. Such, in the most general terms, is the theory advanced to account for the accepted fact of evolution.
The question is as to the influence of this broad fact and its associated theory upon the problems of thought. One striking
