EVOLUTION AND ETHICS 221 



on their own chests, but clashes are said to be exceedingly 

 rare. Chimpanzees, too, form family groups; but they also, 

 at times, gather in rather large clans with loose leadership. 

 Much of the parental care within the family in all these 

 primates is basically like that of the human. 



Early human families joined to form larger groups quite 

 naturally, following the gregarious urge common to their 

 ancestral line. That the tendency was toward the formation 

 of tribes with distinct territories is very clear from the pre- 

 historic and historic record. Darwin endeavored to show 

 that tribal life placed certain restrictions on the individual 

 members in return for the greater capacity organization 

 gave in obtaining food. He pointed out that in this coopera- 

 tive unit (the tribe) the "great principle of acting for the 

 good of the species, could hold sovereign sway." Certainly 

 no tribe could "hold together if murder, robbery, or treach- 

 ery were common." There must be a readiness to sacrifice 

 for the common good; there must be courage and sympathy. 

 Selection, he thought, would obviously work quickly and 

 lethally against any unit the members of which were inces- 

 santly quarreling and who lacked innate impulsions toward 

 mutual aid. 



This was not new, but Darwin gave it emphasis even if 



some of his immediate followers did overlook it. Plato lonor 



..... ^ 

 before had pictured the harmonious society in which justice 



prevailed as being fit for survival. In such a society the just 

 man lived by good intent and desire, giving the full equiva- 

 lent of what he received, making the harmonious function- 

 ing of the elements in himself and in the society a coopera- 

 tive contribution to behavior. Disharmony was evil, whether 

 between man and himself, or man and society, or man and 

 nature. Kant had seen that there is a disposition toward so- 

 cial behavior, that the moral sense is innate; but Kant had 

 failed to see that the content of conscience is acquired, as 

 Aristotle had indicated, on the basis of experience and ob- 

 servation of life, not on theory. 



