Human Infancy and the Recapitulation Theory 91 



evolution of intelligence has derived added support from the 

 views currently held of the historical increase in complication 

 of the nervous system, especially of the cerebral portions. The 

 original segmental nervous system has been successively inte- 

 grated, first by co-ordinating centers of limited scope, and suc- 

 cessively by hierarchies of increasing range and inclusiveness. 

 This evolution has been in the main one of gradual progression 

 in a given direction, and those portions associated with intelli- 

 gence are regarded as being peculiarly illustrative of this order. 

 In a passage in which he characterizes the method of his work 

 on the evolution of mind Hobhouse speaks somewhat explicitly 

 of the homologies existing between human and animal modes 

 of intelligence. Referring to the stages in mental evolution as 

 summarized in Chapter XV of his book, this writer says, 



"The fourfold method of correlation differing stage by stage 



(a) in respect of the factors explicitly taken into account, and 



(b) therewith in extent of the sphere comprehended, appears to 

 the writer to be realized in human consciousness as we run the 

 gamut from philosophical reflection down to the quasi-mechan- 

 ical response of habit. Whether these stages into which de- 

 veloped human reason can be analysed correspond to stages by 

 which it grew is of course another question a question only to 

 be answered by a much wider knowledge of animal psychology 

 and of the distinct processes of human development than we at 

 present possess. If we accept evolution, analogy suggests that 

 human intelligence is a specific and higher development of a 

 more general form of intelligence. Hence, if we cut away the 

 higher development, we should come to something roughly 

 common to man and the higher animals. If we cut further, 

 we should come to something common to man and a wider 

 class of animals, and so forth. But there is a caution to be 

 borne in mind. No two species will come to a quite identical 

 development. No part of the physical structure of man, I 

 suppose, is precisely equivalent to the homologous part in 

 another mammal, still less in another vertebrate of a different 

 class. It is the same with the mental structure. We must not 

 expect to find any animals whose intelligence falls readily into 

 any classification based on the analysis of human experience. 

 We can only expect to find homologous developments. That 

 being understood, it may be said that the method of the preced- 

 ing chapters, so far as they relate to animals, has been to analyze 

 out the phases of intellectual development as distinguishable in 

 human experience, and to discover what homologous structures 



