818 Comparative Morphology of Chordates 



primates. But they are effective biologic factors in that they may 

 determine the survival or nonsurvival of human individuals and 

 groups. All that is best in man will somehow go on. From micro- 

 organism to primitive chordate and thence to man, there has been a 

 steadily progressive increase in range of adaptation to the world's 

 various environments, and primates made a tremendous step onward 

 when they shifted the main line of evolution from structural adapta- 

 tion of the body to modification of the environment and use of en- 

 vironmental energies to augment and supplement those of the body. 



As determining factors in what may lie before him, man's most 

 precious assets consist in that most recent evolutionary acquisition 

 of the vertebrates — namely, the complex of mental attributes which 

 we designate collectively as "ethical." These will serve, even more 

 potently than his intelligence, to carry him through the tempestuous 

 formative stage of his existence and bring him out into a well-ordered 

 world. Intelligent cooperation must replace selfish competition and 

 stupid collective brute force. Tolerance and respect for individual and 

 national liberty must replace unreasoning insistence that all indi- 

 viduals and all nations accept one ideology. A world rich in variety of 

 human cultures is vastly more interesting than the flat monotony of a 

 one-idea world. 



Each cell of the human body and the body as a whole are vitally 

 interdependent. If certain of its cells become functionally deranged, 

 the whole body may suffer illness. Misbehavior of the whole — e.g., as 

 by ingestion of poisonous food — is detrimental to its constituent cells. 

 A similar vital reciprocal relation exists between the human individual 

 and his race. The welfare of the race is merely the collective welfare of 

 its individuals. Mass misbehavior, as in world wars, is fatal to vast 

 numbers of individuals and detrimental to all. Any system, political 

 or economic, which enslaves and mechanizes individuals in order that 

 a group may acquire dominance of some sort is inherently a failure. 

 "All for one and one for all" is a sound biologic principle. In it, self- 

 interest and altruism strangely coincide. The individual may expect to 

 possess the right to life, liberty, and the pursuit (at least) of happiness 

 only when he fully concedes the same right to his fellows — and the 

 light to exercise that right stops at any point of impingement upon the 

 right of another individual. The immediate welfare of the human race 

 and the continuation of the upward progress of vertebrate evolution 

 are the responsibility of every human individual. The main line of 

 evolution has already been shifted from bodily structure into the 

 realm of ideas. It is now becoming apparent that the next step must 

 take us and our primate successors upward to the yet higher level of 

 ideals, 



