1881 ON MENTAL EVOLUTION 101 



tion of even knowing how he is killed. Of course, in 

 a general way I quite understand and agree with 



- that Spencer has done but little service to 

 science. But I believe that he has done grea.t 

 service to thinking, and all the mathematicians in the 

 world would not convince me to the contrary, even 

 though they should all deliver their judgment with 

 the magnificent authority of a -. 



Coming now to the diagram, I am much obliged 

 to you for your suggestions. The ' Descent of Man/ 

 with all its references upon the subject, and also 

 your paper on the ' Baby,' were read, and the results 

 embodied in the diagram, so I am very glad you did 

 not take the needless trouble of consulting these 

 works. By ' Love ' I intend to denote the complex 

 emotion (dependent on the representative faculties) 

 which, having been so lately smitten myself, I am 

 perhaps inclined to place in too exalted a position. 

 But you did not observe that I placed ' Parental Affec- 

 tion ' and ' Social Feeling ' very much lower down. 



In my essay I carefully explain the two cases 

 of Drosera and Dionaea as being the best hitherto 

 observed for my purpose in establishing the prin- 

 ciple of discrimination among stimuli, as a principle 

 displayed by non-nervous tissues. 



April 22, 1880. 



As soon as I received your first intimation about 

 Schneider's book I wrote over for it, and received a 

 copy some weeks ago. I then lent it to Sully, who 

 wanted to read it, so do not yet know what it is 

 worth. I, together with my wife who reads French 



