EVOLUTION 25 



Returning now to the earlier history of the modem 

 doctrine of Evolution, it is admitted that the publication 

 of the Origin of Species gave such an enormous stimulus 

 to evolutionary thought that Spencer's writings received 

 much greater attention than would otherwise have been 

 accorded to them. The highly abstract reasoning and the 

 more purely deductive treatment in the First Principles 

 and its successors did not appeal to the majority of 

 scientific workers with such force as Darwin's more con- 

 crete method of deahng with the problem of organic 

 evolution. Spencer himself, with that candour which 

 throughout marked his attitude toward his great con- 

 temporary, has admitted this influence in specific terms 

 in relating the history of the revision of the first (1855) 

 edition of his Principles of Psychology :— 



' The tacit assumption, and towards the close of the 

 work the avowed belief, that all organisms had arisen by 

 evolution, and the consequent conception miming through- 

 out the whole work that the phenomena of mind were to 

 be interpreted in conformity with that hypothesis neces- 

 sarily (in 1855), roused not sjmipathy, but antipathy. 

 It was only after the pubUcation of Mr. Darwin's Origin 

 gf Species, some four years subsequently, and only after 

 this work — drawing so much attention, causing so much 

 ^ntroversy — ^began presently to affect deeply the beliefs 

 of the scientific world, that the views contained in the 

 Principles of Psychology came to be looked at more 

 sympathetically.' ^ 



In attempting to estimate the relative parts played by 

 Darwin and Spencer in moulding evolutionary thought 

 we must, as before urged, bear distinctly in mind that 

 fundamental difference in method of attack — the expres- 



p. 356, ed. 1900. To prevent possible misunderstanding it may also 

 be advisable to emphasize that the hypothesis of multiple synthesis 

 now suggested has no relationship to the hypothesis of the ' multiple 

 origin ' of species so ably discussed by Professor Poulton in his latest 

 •work, Charles Darwin and the Origin of Species, Appendix A, p. 247. 



' Duncan's Life and Letters, p. 140. Darwin admits (Origin, 6th ed., 

 p. 428) that the foundation on which Psychology had been based by 

 Spencer was ' well laid '. 



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