viii THE EARTH BEFORE HISTORY 



actually be fixed for history in any definite fashion, it may be 

 assumed — at least, as a tentative hypothesis — that the facts of 

 which human evolution is woven, can be grouped in three quite 

 distinct orders. The first are the contingent, the second the 

 necessary, and the third those that relate to some inner logic. We 

 shall try to make use of and to harmonize the very diverse explana- 

 tions that have been attempted, by endeavouring to show that the 

 whole content of human evolution falls into these general divisions 

 of contingency, necessity, and logic. It seems to us that by this 

 tripartite division, history receives both its natural articulation 

 and its whole explanation. Indeed, this classification opens up 

 a deeper view of causality. It invites us to probe into the mass of 

 historical facts and to attempt to disentangle three kinds of causal 

 relations : mere succession, where the facts are simply determined 

 by others : relations that are constant, where the facts are linked 

 to others by necessity : and internal linkage, where the facts are 

 rationally connected with others. On this view of the nature of 

 the causes operating in history, a synthesis may not appear 

 easy, but it is at least conceivable. We have developed this 

 methodological hypothesis x at length elsevohere ; here we would 

 merely summarize briefly its general bearings. 



For societies to take form and to endure they must submit to 

 certain special and necessary conditions which we call institutions. 

 Wherever a society exists there are institutions — at any rate, 

 in outline. We encounter the same fundamental institutions 

 everywhere, although under different forms ; but this diversity 

 is not unlimited in its characteristics, a fact that is to be 

 explained, in part, by the differences existing in the very 

 structure of societies — that is to say, in the number of social 

 units and their concentration or density. " Sociology," when it 

 is conscious and scientific looks upon societies merely as such. 

 The proper work of the sociologist is the study of social organiza- 

 tion from the comparative point of view. In order the better to 

 define its essential functions as translated into institutions, and 

 in order to determine the connexions of these functions with the 

 social structure and their reciprocal inter-relationships , it isolates 

 the social element. This is one of the aspects of historical 

 synthesis, yet only one. A complete historical synthesis brings 

 this element, these necessities or social laws, into renewed contact 



1 La Synthesc en Histoire : Essaz critique et theorique, fan's, 1911 



