40 • GENERAL EVOLUTION. 



mals of the same species vary exceedingly in their sensitiveness 

 to exterior influences ; that is, they differ in the degree in which 

 the same object affects their consciousness. That which excites 

 one is unnoticed by another ; what fills one with alarm scarcely 

 rouses the attention of another. It is well known also that differ- 

 ences in the power of retention are to be found in the same spe- 

 cies of animals. The variations in persistence of memory are 

 very great. While, therefore, one individual of a species will ac- 

 quire a store of "contiguities," another of the same will possess 

 but few. In other words, the degree with which objects are 

 impressed on the consciousness, and the degree with which they 

 are returned to the consciousness, vary greatly in the same spe- 

 cies. Here we have the basis for the origin of totally different 

 unconscious habits and reflex actions, and consequent divergences 

 in the "location of growth-force." 



Those in which these impressibilities are most highly devel- 

 oped will accumulate mental acquisitions most rapidly ; in other 

 words, they will be the most intelligent of their species. While 

 others follow the old routine of once acquired and then inherited 

 habits, those in whom consciousness most frequently recognizes 

 events will originate new acts and new habits. 



Intelligence is a conservative principle, and always will direct 

 effort and use into lines which will be beneficial to its possessor. 

 Here we have the source of the fittest— i. e., addition of parts by 

 increase and location of growth-force, directed by the influence of 

 various kinds of compulsion in the lower, and intelligent option 

 among higher animals. 



Thus, intelligent choice, taking advantage of the successive 

 evolution of physical conditions, may be regarded as the originator 

 of tlie fittest, while natural selection is the tribunal to which all 

 the results of accelerated growth are submitted. This preserves 

 or destroys them, and determines the new ]wints of departure on 

 which accelerated growth shall build. 



If the above positions be true, we have here also the theory of 

 the development of intelligence and of other metaphysical traits. 

 In accordance with it, each trait appropriates from the material 

 world the means of perpetuating its exhibitions by constructing its 

 instruments. These react by furnishing increased means of exer- 

 cise of these qualities, which have thus grown to their full expres- 

 sion in man. 



