Address to the British Association 223 



of the ultimate morphological components of organisms, the 

 powers of the various aggregations of such components, i.e. of 

 the various ' tissues ' and the functions of the different special 

 aggregations and arrangements of tissues which constitute 

 * organs.' 



But as each Hving creature is a highly complex unity — 

 both a unity of body and also a unity of force, or a synthesis 

 of activities — it seems to me that we require a distinct kind 

 of physiology to be devoted to the investigation of such 

 syntheses of activities as exist in each kind of Hving creature. 

 I mean to say that just as we have a physiology devoted to 

 the several activities of the several organs, which activities 

 are the functions of those organs, so we need a physiology 

 specially directed to the physiology of the living body con- 

 sidered as one whole, that is, to the power which is the 

 function, so to speak, of that whole, and of which the whole 

 body, in its totality, is the organ. 



In a word, we need a physiology of the individual. This 

 science, however, needs a distinct appellation. I think an 

 adequate one is not far to seek. 



Such a line of inquiry may be followed up, whatever view 

 be accepted as to the nature of those forces or activities 

 which Hving creatures exhibit. But if we recognise, as I 

 myself think our reason calls on us to recognise, the exist- 

 ence in each living being of such a ' principle of individua- 

 tion ' as I have advocated the recognition of, then an inquiry 

 into the total activity of any living being considered as one 

 whole is tantamount to an inquiry into the nature of 

 its principle of individuation. Such an inquiry becomes 

 ' Psychology ' in the widest and in the original signification of 

 that term — it is the Psychology of Aristotle. 



Mr. Herbert Spencer has already made a great step 

 towards reverting to this original use of the term, for he has 

 made his * Psychology ' conterminous with the animal king- 



