PART I 1 



THE RELATIVE STRENGTH OF NURTURE 

 AND NATURE 



When we approach the fundamental problems of human life, and 

 endeavour to study the causes which make for the physical and mental 

 fitness of a nation, we are at once struck by the vast network of 

 associated factors, which render so complex any attempt at a solution 

 of the simplest problem in the relationship of nurture and environment 

 to human progress. 



We might for example discover that the mentally and physically 

 fitter child comes from the cleaner and less crowded home, and 

 therefore argue that the spread of such homes is a condition for 

 national progress. But further investigation may show that the 

 essential condition for such homes is the existence of mentally and 

 physically fit parents, and that the fitness of the children flows after 

 all from the parentage and not from the home. 



Or again if we take the problem of employment of mothers, we 

 might discover that employed mothers have the healthier children, 

 and we might on this ground oppose any attempt to restrict the 

 factory work of women during childbearing years. But on further 

 investigation we might ascertain that such mothers are, on the 

 average older and have older children, from whom time has weeded 

 the weaklings, and that the problem cannot be solved by the simple 

 question of the physique of the children of employed and unemployed 

 mothers, without regard to the age distribution of the children. 



Once more it is conceivable that we might find the deathrate 

 of innkeepers much in excess of the deathrate of the clergy, and 



1 This paper was originally delivered as the seventh of a course of Eight Lectures 

 on National Eugenics at the Galton Laboratory, 1909. 



