METHODS 71 



what are the different ways of dogging or ducking with 

 relation to this or that circumstance. 



For such odd verbs we may substitute the verb " to 

 function" on condition that it be understood the word 

 comprises all the specific activity of the being considered, 

 under the circumstances considered. This manner of speech 

 will give to the word junction a meaning quite different 

 from that of the physiologist. There will no longer be 

 question of an artificial decomposition of the total activity 

 of an individual into several simultaneous parts which we 

 have no right to separate from each other. But it will be 

 the decomposition of a succession of total activities, each 

 of which is the result of two factors, the state of the animal 

 we consider and the surrounding conditions taken all 

 together at the moment we consider it. 



Each function thus defined will be singular, differing from 

 all others in the world. There are, indeed, too many 

 elements in each animal and too many also in the circum- 

 stances which determine its acts, for a being of one species 

 ever to find itself twice identically the same in identical 

 circumstances. So it would be an illusion to look for some- 

 thing common in the sum total of functions dog defined in 

 this way ; they will vary ad infinitum. It would be even 

 more impossible to find anything common to functions dog, 

 functions lizard, and functions pear-tree. Not even in the 

 nature of these functions can we find a general law ; but 

 we may discover one in the linking together of the successive 

 functions of one and the same individual and in the conse- 

 quences to a given individual of its exercising a given 

 function. 



We have not at our disposition the imaginary bioscope 

 which might enable us to recognize from mere inspection the 

 physical state peculiar to living substances. Here too we 



