BIOLOGICAL EVOLUTION 65 
change in the evolutionary process when natural selection turned 
from the development of the organism to the development of 
intellectual power, “for man is enabled through his mental 
faculties ‘ to keep with an unchanged body in harmony with the 
changed universe.’”? He invents weapons, tools, and various 
stratagems, by which he procures food and defends himself. 
When he migrates into a colder climate he uses clothes, builds 
sheds, and makes fires.1_ Whata contrast this to that of the lower 
animals, who “ must have their bodily structure modified in order 
to survive under greatly changed conditions.” 
The development of intelligence and sagacity in earliest times 
enabled the tribes whose members were best endowed to supplant 
the other tribes, even as today in various parts of the world? 
With the development of men in society, progress became more 
rapid through imitation, reason and experience. Likewise were 
developed sympathy, fidelity, courage and obedience to authority. 
“A tribe possessing the above qualities in a high degree would 
spread and be victorious over the other tribes; but in the course 
of time it would, judging from all past history, be in its turn 
overcome by some other and still more highly-endowed tribe. 
Thus the social and moral qualities would tend slowly to advance 
and be diffused throughout the world.” 4 
From experience the value of co-operation was learned, habits 
formed and sympathy developed, which after many generations 
became fastened upon the organism as an instinct. Thus, too, 
originated other social virtues such as the praise and blame of 
fellow-men, love of approbation and dread of infamy, and remorse 
at the consciousness of failure in the performance of duty. Later 
the self-regarding virtues developed, such as temperance, chastity, 
etc., based on experience of the results of conduct.® 
As Darwin’s argument concerning the working of the law of 
natural selection among civilized nations is built so largely on the 
labors of such investigators as W. R. Greg and Francis Galton, 
we will pass over the subject for the present and turn to another 
1 Descent of Man, p. 152. 4 Ibid., p. 156. 
2 Ibid., p. 154. i Ibid., p. 157. 
3 [bid., p. 155. 6 Ibid., p. 158. 
