The Psychological and the Biological 5 



case what they are because the particular parents mated ; 

 but the particular parents mated because one of them 

 recognized the other. The psychological fact of recog- 

 nition is as necessary to the result as is the process of 

 reproduction. It is a rule, indeed, that for science all 

 facts are equal. Such a rule enables us to avoid the 

 recondite question as to which province is to take pre- 

 cedence in this case or that, provided we are deahng 

 explicitly with a problem to which both sorts of fact are 

 relevant. 



The recognition of psychological facts becomes especially 

 important in view of the separate way in which analogous 

 questions are often put in the two sciences of psychology 

 and biology respectively. The discussion of the respec- 

 tive spheres of these two sciences turns upon a distinc- 

 tion of points of view. On the one hand, the psychologist 

 as such, and for his science, must aim at the recognition 

 only of the facts which are psychic or mental ; that is, 

 of such as are facts to the consciousness in which they 

 occur. These alone are psychic, and these belong to in- 

 dividual psychology. So soon as we take up, however, the 

 standpoint of the observer, that of the scientific man who 

 essays to investigate some one else's consciousness y or that 

 of an animal, the procedure is now subject to different 

 rules and limitations of observation. To use the terms 

 of a recent distinction of terminology,^ the facts, while 

 psychological^ are yet to the observer not psychic. The 

 investigation which we set ourselves when we come to 

 discuss psychophysical evolution is * psychological ' in 

 this sense, that is, objective. In the earlier volumes of 



1 Cf. the writer's Dictionary of Philosophy and Psychology, art * F^chic 

 and Psychological.' 



