SCIENCE OF HISTORY. 531 



attainable degree of knowledge would enable us to foresee, 

 occur, when considerable numbers are taken into the account, 

 with a degree of regularity approaching to mathematical. 

 What act is there which all would consider as more completely 

 dependent on individual character, and on the exercise of 

 individual free will, than that of slaying a fellow creature ? 

 Yet in any large country, the number of murders, in propor- 

 tion to the population, varies (it has been found) very little 

 from one year to another, and in its variations never deviates 

 widely from a certain average. What is still more remarkable, 

 there is a similar approach to constancy in the proportion of 

 these murders annually committed with every particular kind 

 of instrument. There is a like approximation to identity, 

 as between one year and another, in the comparative number 

 of legitimate and of illegitimate births. The same thing is 

 found true of suicides, accidents, and all other social pheno- 

 mena of which the registration is sufficiently perfect ; one of 

 the most curiously illustrative examples being the fact, ascer- 

 tained by the registers of the London and Paris post-offices, 

 that the number of letters posted which the writers have for- 

 gotten to direct, is nearly the same, in proportion to the whole 

 number of letters posted, in one year as in another. " Year 

 after year," says Mr. Buckle, "the same proportion of letter- 

 writers forget this simple act; so that for each successive 

 period we can actually foretell the number of persons whose 

 memory will fail them in regard to this trifling, and as it might 

 appear, accidental occurrence."* 



This singular degree of regularity en masse, combined with 

 the extreme of irregularity in the cases composing the mass, 

 is a felicitous verification a posteriori of the law of causation 

 in its application to human conduct. Assuming the truth of 

 that law, every human action, every murder for instance, is the 

 concurrent result of two sets of causes. On the one part, the 

 general circumstances of the country and its inhabitants ; the 

 moral, educational, economical, and other influences operating 

 on the whole people, and constituting what we term the state 



* Buckle's History of Civilization, i. 30. 

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