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IV. 



CHANCE. 



I. 



" How can we venture to speak of the laws of chance ? 

 Is not chance the antithesis of all law?" It is thus 

 that Bertrand expresses himself at the beginning of 

 his "Calculus of Probabilities." Probability is the 

 opposite of certainty ; it is thus what we are ignorant 

 of, and consequently it would seem to be what we 

 cannot calculate. There is here at least an apparent 

 contradiction, and one on which much has already 

 been written. 



To begin with, what is chance ? The ancients 

 distinguished between the phenomena which seemed 

 to obey harmonious laws, established once for all, 

 and those that they attributed to chance, which were 

 those that could not be predicted because they were 

 not subject to any law. In each domain the precise 

 laws did not decide everything, they only marked 

 the limits within which chance was allowed to move. 

 In this conception, the word chance had a precise, 

 objective meaning ; what was chance for one was 

 also chance for the other and even for the gods. 



But this conception is not ours. We have become 

 complete determinists, and even those who wish to 



