180 EVOLUTION AND SOCIAL PROGRESS 



the grossest materialistic evolution, which they 

 mistake for gospel truth, are according to Kel 

 logg s own statement not seldom innocent of any 

 real acquaintance with science. Hence their blind 

 adherence to the recapitulation theory, as the 

 hypothesis of the Haeckelian biogenetic principle 

 is usually called. It is well worth quoting Vernon 

 Kellogg s words on this subject. Coming from 

 such a pronounced materialist they may possibly 

 be appreciated the better. He says : 



To my eyes, much biological sociology rests on two very in 

 secure bases; (i) a too slight acquaintance with biology on the 

 part of the biological sociologists, and, (2) an acceptance of, 

 and confidence in, certain biological theories which are cer 

 tainly unwarranted, and are not all shared by biologists 

 themselves. Biological science contains much that is proved 

 and certain; but also much that is nothing more than a working 

 hypothesis, provisional theory and anticipatory generalization. 



As the proved part is largely of facts of observation, isolated 

 and unrelated, and the unproved part is composed of the large 

 and sweeping generalizations, the plausible, provisional ex 

 planations, such as the various theories of heredity, of the 

 results of struggle, of the development of mutual aid, etc., i.e., 

 is exactly the sort of material that the sociologist needs to 

 weave into his biological foundations for the sociological study 

 of man, it is exactly this unproved part of biology that the 

 searching sociologist carries home with him from his excursions 

 into the biological field. 



The recapitulation theory looms up large and familiar in 

 biological sociology; it is mostly discredited in biology. The 

 inheritance of acquired characters serves as a basis for much 

 sociology; most biologists believe it is impossible. The 

 selection theories are gospel to some sociologists ; they are the 

 principal moot points in present-day biology. And so on. 



Biology is not as yet come to that stage in its development 



