444 PHYSICAL DETERIORATION & MICROBIC DISEASE 



the deterioration will vanish in the very next generation. Judging, 

 however, by the evidence given before various Royal Commissions 

 by multitudes of medical men and others, I have been very much 

 alone in this opinion until recently. We shall deal more at length 

 with the question immediately. 



727. If the physical use-acquirements are mere extensions of 

 growth made under the stimulus of nutriment, the same is more 

 rarely true of mental acquirements. Sensations, instincts, and 

 memory (all ' innate ' traits) differ sharply from the contents of the 

 memory (all ' acquired ' characters.) It is true that a few instinc- 

 tive emotional impulses (e.g. the parental) are extended by ac- 

 quirement. It is true also that we acquire through experience 

 emotional impulses to action and ' physical ' dexterities which are 

 close imitations of true instincts and instinctive movements. The 

 latter emotions and dexterities, however, are not usually extensions 

 of previously existing characters. For example, nothing like an 

 inborn love of a particular religion or of dexterity in handling a 

 billiard cue is inborn in the individual. These and their like are 

 entirely new creations due to experience and developed in the 

 individual in lieu of any one or more of a thousand alternative 

 emotions and dexterities equally possible of attainment. 



728. It follows that, in the case of mind more than in the case 

 of the body, there is scope for improvement without resort to 

 selection. The human being is capable of developing mentally so 

 greatly, in so many directions, and under the influence of so many 

 varieties of experience, that probably no man, no matter how 

 careful his training, nor what ideals moral, social, religious, 

 intellectual, practical, and so forth his educators had in mind, 

 ever received a perfect mental up-bringing, ever developed mentally 

 in as perfect adaptation to his total environment as was possible to 

 him. In the absence of perfect knowledge and wisdom, the choice 

 of his guardians has always fallen short of perfection. A man can- 

 not be taught all knowledge, and many useful or admirable mental 

 habits and attitudes are incompatible with others. Nevertheless, 

 as fitting the individual for his environment, the mental training 

 of most men somewhat approaches the ideal. And this is more 

 especially the case in savage and therefore comparatively simple 

 states of society. Sport, imitativeness, curiosity, and the instinct 

 to play with the contents of the memory, lay the foundations, and 

 the child's educators, consciously and unconsciously, strive to repro- 

 duce in him the traits which enabled them to survive in the 

 common environment. Other traits, even if ideally desirable, 



