He said, "If the one tribe included a great number of courageous, sympathetic and faithful members who are always ready to aid and defend each other, this tribe would succeed better and conquer the other."
다윈이 말하길, "한 종족이" "항상 서로를 보호하고 돕는" "용기있고, 동정심 많고, 충성스러운 구성원으로" "종족을 이루고 있다면," "이 종족이 더 성공적이고" "다른 종족을 정복 할 것이다."