5 4 ARISTO CRA C Y AND E VOL UTION 



Book i sociologists, complained of by Mr. Kidd and 

 Professor Marshall, to throw on these problems 

 any definite light is simply the natural and inevi- 

 table result of excluding the differences in question 

 altogether from their scientific purview. 



We will, in the next chapter, consider the whole 

 range of arguments used by Mr. Spencer and others 

 in justification of this error. 



