viii PREFACE 



With the growth of Butler's reputation "Life and 

 Habit" has had much to do. It was the first and 

 is undoubtedly the most important of his writings on 

 evolution. From its loins, as it were, sprang his three 

 later books, " Evolution Old and New," " Unconscious 

 Memory," and " Luck or Cunning ? ", which carried its 

 arguments further afield. It will perhaps interest 

 Butler's readers if I here quote a passage from his 

 note-books, lately published in the " New Quarterly 

 Eeview " (Vol. III. No. 9), in which he summarizes his 

 work in biology : 



" To me it seems that my contributions to the theory 

 of evolution have been mainly these : 



" 1. The identification of heredity and memory, and 

 the corollaries relating to sports, the reversion to 

 remote ancestors, the phenomena of old age, the causes 

 of the sterility of hybrids, and the principles under- 

 lying longevity all of which follow as a matter of 

 course. This was ' Life and Habit ' [1877]. 



" 2. The re-introduction of teleology into organic 

 life, which to me seems hardly, if at all, less important 

 than the ' Life and Habit ' theory. This was ' Evolu- 

 tion Old and New ' [1879]. 



"3. An attempt to suggest an explanation of the 

 physics of memory. This was ' Unconscious Memory ' 

 [1880]. I was alarmed by the suggestion and fathered 

 it upon Professor Hering, who never, that I can see, 

 meant to say anything of the kind, but I forced my 

 view upon him, as it were, by taking hold of a sentence 

 or two in his lecture, 'On Memory as a Universal 

 Function of Organised Matter/ and thus connected 

 memory with vibrations. 



"What I want to do now (1885) is to connect vibra- 

 tions not only with memory but with the physical con- 

 stitution of that body in which the memory resides, 



