294 THE PRINCIPLES OF HEREDITY 



the size of the brain and the degree of intelligence. Brains 

 may be developed under various forms of use. For example, 

 a man may acquire a knowledge of classics, or mathematics, 

 science, commerce, and so on. Presumably the most severe 

 study would tend to develop the brain most ; but the effect 

 on the intelligence might not be commensurate. Thus 

 Chinese statesmen are all literati; their studies are ex- 

 tremely arduous ; their brains are large ; but they are not 

 especially renowned for wisdom. IrPbrief terms stupidity 

 may be acquired as well as intelligence ; and it may be 

 acquired at the cost of much labour. 



468. Apart, however, from this innate capacity to make 

 acquirements, are the acquirements actually made by virtue 

 of it ? We cannot doubt that an English child reared by 

 Australian Blacks would make acquirements very similar to 

 those of his educators. Indeed he could make no other. 

 There does not perhaps exist a potential senior wrangler 

 among the Blacks, but judging from such children of savage 

 parentage as have been reared in civilized communities, the 

 average Bushman can be brought under fit training to 

 resemble closely in his mental traits the average English- 

 man. Except in relation to narcotics, the incapacity to 

 become civilized is physical, not mental. It follows that by 

 far the greater part of the mental differences between races, 

 probably all that is observable, is due, not to innate mental 

 peculiarities (instinct and capacity), but purely to acquire- 

 ments. We have noted the extreme parsimony of Nature. 

 Except as regards a few bi-products (e.g. the delight in 

 narcotics) she evolves only those traits which are useful to 

 the race, while she steadily eliminates all those which are 

 useless. It is not believable, therefore, that Natural 

 Selection can have produced such inborn mental differences 

 between races as are meant when it is said that the English- 

 man is " by nature " resolute, the Frenchman mercurial, the 

 Italian excitable, the Dutchman phlegmatic, the West 

 African cruel, and so forth. For it can hardly be that the 

 environment in which the English evolved has so differed 

 from the environments in which the French, the Italians, 

 the Dutch, and the West Africans have evolved, that survival 

 of the fittest in the case of Englishmen has caused in them 

 a greater evolution of resolution and the nervous structures 

 which in that case must be correlated to resolution than it 

 has caused in the other nations named. It can hardly be 

 that the Frenchman is inherently mercurial because the 

 environment of his ancestry was such that superior vivacity 



