72 CREATIVE EVOLUTION CHAP. 



of very complex structure and very delicate function. 

 Here it is impossible to identify changes that are simply 

 solidary with changes which are also complementary. 

 The two senses of the word &quot;correlation&quot; must be 

 carefully distinguished ; it would be a downright 

 paralogism to adopt one of them in the premisses of 

 the reasoning, and the other in the conclusion. And 

 this is just what is done when the principle of correlation 

 is invoked in explanations of detail in order to account 

 for complementary variations, and then correlation 

 in general is spoken of as if it were any group of 

 variations provoked by any variation of the germ. 

 Thus, the notion of correlation is first used in current 

 science as it might be used by an advocate of finality ; 

 it is understood that this is only a convenient way of 

 expressing oneself, that one will correct it and fall back 

 on pure mechanism when explaining the nature of the 

 principles and turning from science to philosophy. 

 And one does then come back to pure mechanism, 

 but only by giving a new meaning to the word 

 &quot; correlation,&quot; a meaning which would now make 

 correlation inapplicable to the detail it is called upon 

 to explain. 



To sum up, if the accidental variations that bring 

 about evolution are insensible variations, some good 

 genius must be appealed to the genius of the 

 future species in order to preserve and accumulate 

 these variations, for selection will not look after this. 

 If, on the other hand, the accidental variations are 

 sudden, then, for the previous function to go on or 

 for a new function to take its place, all the changes 

 that have happened together must be complementary. 

 So we have to fall back on the good genius again, 

 this time to obtain the convergence of simultaneous 



