CHAPTER II 



Comparative Conceptions 



§ I. Recapitulation 



This way of looking at the two spheres of development 

 and evolution, as involving an application of the one prin- 

 ciple of parallelism, carries with it certain consequences of 

 considerable interest. In the first place, it requires us to 

 carry over into the genetic treatment of psychology the 

 same thorough-going genetic point of view which evolu- 

 tion postulates in biology. And with this goes the question 

 of the application to the facts of the one of the principles 

 already established for the other. The great law of recapit- 

 ulation at once comes to mind, the law with which we have 

 been having considerable to do in the earlier volumes of 

 this series. If we hold that mind and brain processes are 

 parallel as well in the species as in the individual, and also 

 hold that the brain series in the individual's development 

 recapitulates in the main the series gone through by his 

 species in race descent or evolution ; then it follows 

 that the law of recapitulation must hold also for the 

 mental. This has been recognized and the limitations of 

 it have been pointed out in Chap. I. of Mental Develop- 

 ment : 1 and a further general application of the idea to 



1 In that place, under the topic ' Analogies of Development,' the main 

 ' epochs ' of growth in each series, which illustrate the recapitulation of evolu- 

 tion by development, are briefly indicated. The following quotation from 

 that work presents a preliminary statement of the general thought which is 

 now worked out explicitly and with greater detail in these pages : " Assuming 

 then that there is a phylogenetic problem, — that is, assuming that mind has 



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