530 SOCIAL ASPECTS OF BIOLOGICAL RESULTS 



inherited in the same way, and at the same rate as the 

 physical. 



But one of the general points of this chapter may be illustrated 

 here. In proportion as we succeed in analysing out the biological 

 factors in our Natural Inheritance shall we see clearly what is 

 meant by " Social Heredity." What do we mean by it ? Not 

 merely that facts of family and stock inheritance may have 

 great social importance, whether they concern the history of 

 a dynasty or the physical deterioration of a proletariat ; not 

 merely that great biological generalisations, such as Filial Re- 

 gression, or the inverse ratio between rate of reproduction and 

 degree of individuation, have direct sociological relevancy ; not 

 merely that there are probably obscure laws of periodic re- 

 currence, such as " the law of generations " ; we mean especially 

 that complex process by which much of what is most precious 

 to us appears to be sustained from generation to generation in 

 a social heritage, by tradition, conventions, institutions, laws, 

 and the whole framework of society itself. It is here that 

 the biologist leaves off, and the sociologist must come in. 



5. Directive Factors in Evolution 



Selection. Passing now to the directive factors in evolution 

 in contrast to those which are originative and conservative, 

 we find practical unanimity in recognising the importance of 

 selective processes. We use a plural phrase in protest against 

 the persistent fallacy of taking a narrow and crude view of what 

 occurs in many different modes, at many different levels, and 

 with very varied degrees of intensity. 



Variety of Modes, Levels, and Intensity in Selective Pro- 

 cesses. As Darwin clearly indicated, the phrase " struggle 

 for existence " is to be taken in a wide and metaphorical sense. 

 In point of fact, it is in operation whenever and wherever the 

 degree of effectiveness of vital response is of critical moment, 



