CHAPTER XX 

 THE PRINCIPLE OF CO-OPERATION 



Espinas (1878) approached his task of organizing the materials 

 available concerning animal societies with much the same point of 

 view that we have developed from a behavioristic and ecological 

 approach to the problem, the study of which has led to the present 

 volume. Espinas says in his introduction to Des societes animates, 

 "No living being is solitary. Animals, especially, sustain multiple 

 relations with the organisms of their environment; and, without 

 mentioning those that live in permanent intercourse with their kind, 

 nearly all are driven by biological necessity to contract, even if 

 only for a brief moment, an intimate union with some other member 

 of their species. Even among organisms devoid of distinct and 

 separate sexes, some traces of social life are manifested, both among 

 animals that remain, like plants, attached to a common stock, and 

 among the lowly beings which, before separating from the parental 

 organism, remain for some time attached to it and incorporated in 

 its substance. Communal life, therefore, is not an accidental fact 

 in the animal kingdom; it does not arise here and there fortuitously 

 and, as it were, capriciously; it is not, as is so often supposed, the 

 privilege of certain isolated species in the zoological scale, such as 

 the beavers, bees, and ants, but, on the contrary — and we believe 

 we are in a position to prove this statement abundantly — a normal, 

 constant, universal fact. From the lowest to the highest forms in the 

 series, all animals are at some time in their lives immersed in some 

 society; the social medium is the condition necessary to the conser- 

 vation and renewal of life. This is, indeed, a biological law which it 

 will be expedient to elucidate. Moreover, from the lowest to the 

 highest stages in the series, we detect in the development of social 

 habits a progression which, if not uniform, is at least constant, so 

 that each social group carries the perfecting of these habits a little 

 farther in one or another direction. Finally, social facts are subject 



352 



