388 D'ALEMBERT. 



his severer studies was found in teaching these little 

 ones. 



It has been alleged, and certainly has been some- 

 what found by experience to be true, that the habit of 

 contemplating necessary truth and the familiarity with 

 the demonstrative evidence on which it rests, has a 

 tendency to unfit the mind for accurately weighing 

 the inferior kind of proof which we can alone obtain 

 in the other sciences. Once finding that the certainty 

 to which the geometrician is accustomed cannot be 

 attained, he is apt either to reject all testimony, or to 

 become credulous by confounding different degrees of 

 evidence, regarding them all as nearly equal from their 

 immeasurable inferiority to his own species of proof 

 much as great sovereigns confound together various 

 ranks of common persons, on whom they look down 

 as all belonging to a different species from their own. 

 In this observation there is, no doubt, much of truth ; 

 but we must be careful not to extend its scope too far, 

 so as that it should admit of no exceptions. The fol- 

 lowing life affords one of the most remarkable of these ; 

 as far as physical science went, Laplace afforded 

 another; in several other branches he was, perhaps, 

 no exception to the rule.* 



The hold which their favourite studies have, and 

 keep over geometricians is not the least remarkable 

 proof of the gratification which they are calculated to 

 afford. I well know, to take one instance within my 

 own observation, that my learned and esteemed friend, 

 the present Lord Chancellor, a most successful student 

 of the mathematics in his earlier years, reverted to the 

 pursuits in which he had so often found delight, long 



* It is said that when the Emperor asked him -why he had left out the 

 consideration of a Supreme Intelligence in his speculations, he answered 

 that he conceived he could explain the phenomena without that hypothesis. 

 But when we look to his demonstration of the high improbability of the 

 system having been formed without an intelligent cause, (above four 

 millions of millions to one he proves it in his Calcul de Frobabilite,) we 

 cannot lend much faith to this Paris anecdote. 



