The Psychological Consequences of Heredity. 3 1 9 



in. 



We have now seen how, on certain hypotheses, heredity con- 

 tributes towards the creation of intelligence. We now propose to 

 turn aside from this radical solution, and to inquire how it contri- 

 butes towards its development. We here use the word intelligence 

 in a sense at once common and philosophic, as that faculty of 

 judgment, ratiocination, and abstraction which in conduct is 

 denominated prudence, good sense, tact, dexterity, penetration; 

 in art, inventiveness, taste ; in science, the faculty for discovery, 

 for generalization, and for detecting relations. Having already 

 proved by sundry facts from normal and morbid psychology and 

 from history the existence of intellectual heredity, we will take it ' 

 for granted here as an empiric law, and we will investigate its 

 consequences. ' 



If we consider heredity under purely ideal conditions, nothing 

 can be simpler than to determine its consequences : it fixes and 

 preserves the modes of intelligence as they appear. Thus some 

 variety of the intelligence humour, for instance appears in an 

 individual either by spontaneous variation, or by that chance 

 concurrence of causes which has been called spontaneity : now 

 if heredity alone were at work it would transmit this mental 

 modification uninterruptedly to all the succeeding generations. 

 But, as we have seen, it meets with hindrances of every descrip- 

 tion, which tend to weaken or even to destroy it. Yet if, in- 

 stead of considering isolated cases where heredity appears to be 

 at fault, we consider a large number of cases ; if we invoke what 

 has been called the law of numbers, the exception disappears, the 

 accidental vanishes, and the law, or, in other words, the essential 

 character, takes the chief place. Thus it is that heredity con- 

 tributes to the formation of national character. A certain turn of 

 mind may easily fail to be perpetuated in a family ; but if it is 

 common to a tribe, a people, a race, it is safe to say that it must 

 be perpetuated. We have seen how closely at bottom the French 

 mind resembles the Gallic mind, as described by Strabo, Diodorus 

 Siculus, and other ancient historians. Thus, in the formation and 

 conservation of the special character of a family or of a nation, 

 heredity is a very important factor. But not to dwell here on this 



