INTRODUCTION 



doubt whether, in this direction, he would have 

 altered any of his notable theses. The modern 

 controversy concerning the " Factors of Ev- 

 olution," the modern inquiry regarding the 

 " Heredity of Acquired Characters," the re- 

 cent researches into the origin of Instincts, — all 

 these topics have been alluded to in the course 

 of the foregoing notes. It is such matters as 

 these that, as I ventured to say at the begin- 

 ning of this Introduction, have " placed many 

 aspects " of the doctrine of evolution " in a de- 

 cidedly new light." It is tolerably plain that, on 

 the whole, regarding these newer issues, Fiske 

 would have remained on Spencer's side. Yet, 

 had he rewritten this book, he could not have 

 ignored topics so central in modern evolution- 

 ary discussion. Morever, in any restatement of 

 his views of Spencer's Psychology, Fiske would' 

 have been forced to take account of at least the 

 existence of modern Experimental Psychology, 

 — a branch of inquiry that did not exist when 

 he wrote, but that has set in new lights some 

 topics which he discussed. He would have been 

 obliged, also, to give some attention to those 

 efforts to attach these same recent psychological 

 investigations to the theory of evolution, which 

 are represented by books like Professor Bald- 

 win's " Mental Development in the Child and 

 in the Race." Modern cerebral physiology, so 

 cxlvii 



