144 ELEVENTH REPORT. 



ment. This field, totally neglected by all psychologists from the time of 

 Aristotle until the time of Darwin, is now seen to be the one in which can 

 best be studied the phenomena that most urgently demand explanation. 

 The changes of personality; the sudden growth of instincts; the operations 

 of feelings and their function in mental life, all these when studied in children 

 l)y the aid of evolutionary principles, have thrown such a flood of light upon 

 the nature of mental processes as to render obsolete and useless all works 

 upon psychology that are based upon the conceptions of a pre-evolutionary 

 age. Jt is a field that would never have been cultivated under the paralyzing 

 influence of the doctrine that mind is a metaphysical entity using the body 

 merely as an instrument, but dependent upon it only as a means of expres- 

 sion and for producing motion in material things. 



Evolution has shown us, also, the kinship existing between men and other 

 animals in the psychological world. Unfortunate!}', psychologists have 

 generally not been acquainted with animal life and structures sufficiently 

 to study the subject with advantage, and zoologists have been too busy, or 

 too little informed al)out psychological processes to make such a study 

 profitable. Hence we find in this field of mental phylogeny the most diver- 

 gent and contradictory opinions maintained in places where we have the 

 right to expect the most profitable studies to be made, and the greatest 

 unity of method and conclusion to prevail. The doctrine of evolution/ 

 here, must be our guide out of the labyrinth. 



From this time forward it seems probable that psychologists will recognize 

 that natural selection, in its application to human development, at least, 

 has been a selection by means of characteristics that belong, not to the 

 ])hysical alone, nor to the psychical, but to the total complex of the psycho- 

 physical organism. There have been not two movements in evolution, 

 a physical and a psychical, but the two series have been carried forward 

 together, constituting a single genetic movement. This conception was 

 impossible so long as it was believed that the mind and the l)ody were two 

 different entities instead of being a single complex. It seems evident, now, 

 that the body has developed in consequence of the selection by psychic 

 processes of variations which without psychical selection would have been 

 destroyed or overlooked. The law of functional selection is necessary for 

 any satisfactory understanding of the method l)y which Darwinism is applied 

 to the human being at least, and functional selection depends upon psychical 

 processes. 



Equally necessary is it to take into account the variations of the body 

 in any attempt to explain the origin and real significance of mental pro- 

 cesses that have been the subject of study from the time of Aristotle down- 

 ward. It would have been impossible for the mind to develop by the selec- 

 tion of utilities for which the body presented no variations. Mind in man 

 has become what it is in consequence of the variations that the body has 

 exhibited. 



It seems that the dynamogenetic law has been thoroughly established 

 in psychology. But the law of dynamogenesis itself is an application of 

 the law of natural selection. Every conscious voluntary act is an example 

 of the Darwinian principle of natural selection and no act of consciousness 

 can produce a voluntary act unless the variation that has been psychically 

 selected has been previously established. 



Without any question, the prevailing psychology of today is German 

 psychology. Until recently, psychology was essentially an English science; 

 ])ut Fechner. Weber and Wunclt have directed it into such a path that it 



