PSYCHICAL EVOLUTION 141 



The same great trunk impulses that animate men 

 animate also those more rudimentary but not less 

 real individuals below and around men. The 

 great primary facts of sex, of self-preservation, of 

 pleasure and pain, of life and death, of egoism and 

 altruism, of motherhood, of alimentation, etc. 

 all of these are found everywhere, down almost to 

 the very threshold of organic life. And they are 

 the antecedents of the same great tendencies as 

 those that control the lives of men. It is often 

 supposed by the superficial that the facts of sex 

 and alimentation, which are so prominent in other 

 animals, have been relegated to a very subordinate 

 place in the nature of man. But nothing could 

 be much farther from the truth. It has been said 

 that there are only two things that will induce the 

 typical African or Australian to undergo prolonged 

 labour hunger and the sex appetite. It is probable 

 that men not only primitive men, but the most 

 evolved races, including even poets and philoso- 

 phers will do more desperate and idiotic things 

 and undergo more trying experiences when 

 actuated by the sex impulse than from the effects 

 of any other impulse in human nature. This 

 impulse is especially overmastering in races like 

 the Italian and Spanish, and has been mentioned 

 by ethnologists as a probable factor in the deteri- 

 oration of these races. The sentiments of love, 

 marital affection, and family life control mankind 

 more completely than any other motives. And 

 next to these comes hunger. Let anyone who 

 imagines that only the non-human creatures are 



