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WILLIAM E. CASTLE 
physique and sound minds or skilled hands. In their produc- 
tion the elements of environment, education and family tradi- 
tion must not be disregarded, but after all due allowance is made 
for these factors, it is still true that heredity is an important 
element in producing good family strains no less than bad ones. 
Can a way be found, without undue interference with personal 
liberty, to increase the good human strains and to decrease the 
poor ones? 
Finally there is another problem which the human race must 
face in the light of biology as well as of history, that of popula- 
tion. There is a limit to the number of people who can live 
comfortably on a limited amount of land. It is true that the 
world supports much larger populations now than it did a few 
centuries ago and supports them in much greater comfort, due 
chiefly to advances in applied science, but still many countries 
are overcrowded. Overcrowding leads in time to poverty, 
famine, and war. Would not an intelligent control of the increase 
of population act as a deterrent to war and its attendant miser- 
ies? Our college graduates will not solve the problem by limiting 
the size of their own families. They have gone too far already 
in that direction and are not now replacing themselves in the 
population. Roolsevelt pointed out very clearly the consequences 
of this policy, which he denounced as ^Tace suicide.’’ He did 
not wish to see our children cheated of their birthright, and this 
■fair land won from the wilderness by the daring and toil and 
endurance of our fathers, abandoned by us to the swarming hordes 
of Europe, Asia and Africa. 
At the same time it is not wise for us to adopt a policy of non- 
intercourse with the rest of the world. The part is not greater 
than the whole. Our civilization is European civilization, the 
world civilization of today. When that falls, ours falls. What 
we need is intelligent study of the whole question of population, 
the factors that enter into its increase, its stabilization, and its 
ultimate control. The question should be approached in the 
academic spirit, without bias, without hysteria, without fanati- 
cism, in a spirit of fairness to all races and conditions of men. 
