276 Heredity and Environment 



races shows that evolution may be guided to human advantage 

 by intelligent elimination and selection, and probably any heredi- 

 tary improvement of the human race must be accomplished by 

 this means, though of course such elimination and selection can 

 apply only to the function of reproduction. The method of evo- 

 lution by the elimination of persons, the destruction of the weak 

 and cowardly and antisocial, which was the method practiced in 

 ancient Sparta, is repugnant to the moral sense of enlightened 

 men and cannot be allowed to act as in the past; but the worst 

 types of mankind may be prevented from propagating, and the 

 best types may be encouraged to increase and multiply. This is 

 apparently the only way in which we may hope to improve per- 

 manently the human breed. 



2. No Improvement in Human Heredity within Historic 

 Times. The improvement of environment and of opportunity for 

 individual development enables men at the present day to get 

 more out of their heredity than was possible in the past. Advance 

 of civilization has meant only improvement of environment. But 

 neither environment nor training has changed the hereditary ca- 

 pacities of man. There has been no perceptible improvement in 

 human heredity within historic times, nothing comparable with 

 the changes which have occurred in domesticated animals. In- 

 deed no modern race of men is the equal of certain ancient ones. 

 Galton has pointed out the fact that in the little country of At- 

 tica in the century between 530 and 430 B.C. there were pro- 

 duced fourteen illustrious men, one for every 4,300 of the free 

 born, adult male population. In the two centuries from 500-300 

 B. C. this small, barren country with an area and total popula- 

 tion about equal to that of the present State of Rhode Island but 

 with less than one-fifth as many free persons produced at least 

 twenty-five illustrious men. Among statesmen and commanders 

 there were Miltiades, Themistocles, Aristides, Cimon, Pericles, 

 Phocion; among poets ^Eschylus, Euripides, Sophocles, Aristo- 

 phanes ; among philosophers and men of science Socrates, Plato, 

 Aristotle, Demetrius, Theophrastus ; among architects and artists 



