THE ORIGIN OF VARIATIONS .50 



deduced by Spencer from his general conclusion, 

 reached in § 163 of " First Principles," that there 

 must always be a process of segregation, since evolu- 

 tion consists in a change from the homogeneous, not 

 to a " vague chaotic heterogeneity," but to an orderly 

 heterogeneity. The terminology is somewhat difH- 

 cult to those unfamiliar with it, but the reader is 

 merely asked to note Spencer's arrival by deduction 

 — i.e. reasoning from the general to the particular — 

 at the conclusion that segregation plays a part in 

 variation, ensuring that variation — which is only a 

 special case of universal evolution — is orderly and 

 not chaotic ; and that, in the case wo are considering, 

 it " prevents a homogeneous mean between the two 

 parents." In the next chapter we shall see how the 

 Abbe Mendel reached similar conclusions as to the 

 nature of variations by the opposite method to 

 Spencer's, by induction — i.e. reasoning from the 

 particular to the general — from the experimental 

 facts which he had observed. It is not a little 

 remarkable that Spencer's a priori reasoning, and 

 Mendel's a posteriori reasoning, should have coin- 

 cided in time. It is quite probable that on the very 

 day when Spencer wrote the paragraphs I have 

 quoted, Mendel had conducted experiments on peas ; 

 yet we may be almost certain that neither of them 

 had ever heard the other's name : and science was to 

 wait several decades before the work of the experi- 

 menter was to be brought into correlation with the 

 conclusions of the philosopher. 



