30 ESSAYS OF A BIOLOGIST 



with repetition ; then comes some simple degrees of 

 memory j then associative memory, as in birds and 

 mammals, for whom most reactions are not given in 

 the inherited constitution, but must be learnt ; then 

 rational memory, in which the power of generalization 

 liberates life from blind dependence upon the local and 

 the accidental ; and finally tradition, whereby the 

 amount of experience available to the developing race 

 is not constituted merely by the isolated and limited 

 experiences of its members, but by their sum. More 

 and more of the past becomes directly operative in the 

 present ; further and further into the future can the 

 aims of the present extend. 



Finally we can conclude with a high degree of 

 certainty that the psychical faculties — of knowing, 

 feeling and willing — have increased in intensity, 

 and also in their relative importance for the life of 

 the individual organism. 



We have condensed our summary into these six 

 general statements ; if we wish to reach a still more 

 general form, the most general form possible, we can 

 redistil it thus : During the course of evolution in 

 time, there has been an increase in the control exerted 

 by organisms over their environment, and in their 

 independence with regard to it ; there has been an 

 increase in the harmony of the parts of organisms ; 

 and there has been an increase in the psychical powers 

 of organisms, an increase of willing, of feeling, and 

 of knowing. 



