METHODS 73 



Let us designate A 1} A 2 , A 3 . . . the successive states 

 of an individual, its successive organs, according to our 

 definition ; and B l5 B 2 , B 3 . . . the successive sums total 

 of surrounding circumstances which intervene in deter- 

 mining the activities of the individual. We shall have 

 to consider any activity of our individual, any function 

 whatever, as the result of two factors, its state A 

 at the moment considered, and the sum total B of the corre- 

 sponding circumstances. 



In other words, any moment whatever of an individual's 

 life may be represented by the symbolic formula : 



A x B 



Life, all told, will be a succession of functions 1 , each of 

 which corresponds with a formula : 



A! X B! 

 A 2 x B 2 



A 3 x B 3 



But A 2 is the structural state of the organism after it 

 has accomplished the function (A t x Bi). The body, 

 therefore, passes from the state A t to the state A 2 under 

 the influence of the exterior conditions B 1} which have 

 determined it to execute the function (A t x Bi). 



Thus the general biological problem comes back to this : 

 what is A 2 with relation to A t influenced by circumstances 

 B! determining the function (A 1 x BJ. 



1 This must not be taken as equivalent to the well-known formula 

 of Herbert Spencer the adjustment between internal and external 

 relations which, indeed, is a way of considering the phenomena, 

 a descriptive method applicable to not-living matter as well as to 

 living beings. The true definition is to be found in the result of 

 function, in the law of functional assimilation, which is a theorem 

 demonstrated by experience ; the analysis into functions is an 

 d priori method. 



