44^ Truth and Fafihood. [Book X, 



conformity of the idea with the name; in other words, 

 that in the minds of different perfons the fame name 

 lhall fuggeft the fame idea. 2ndly, A conformity of 

 the idea with fome real exiftence. 3dly, A confor- 

 mity of one idea with another. 



The caufe that a perfon affirms the truth of the 

 propofi.ion, twice two is four, is the entire coincidence 

 of the vifible and tangible idea of twice two with that 

 of four, as impreiTed upon the mind by different ob- 

 jects. We fee every where that twice two and/"#r are 

 only different names for the fame imprefTion. Where 

 the numbers arc fo large, that we are not able to form 

 any diftinft vifible ideas of them, as when we fay, 

 twelve times twelve is equal to one hundred and forty- 

 four, a coincidence of the words arifmg from fome 

 method of reckoning, and refembling the coincidence 

 of words, which attends the coincidence of ideas in the 

 firrpler numerical propofidons, is the foundation of 

 our rational affent ; for we often do, and might always 

 verify the fimpleft numerical propofitions by reckoning 

 up the numbers *. 



Thofe judgments, which relate to determining the 

 probability of future events, appear to be little more 

 than accurately remembering, and felecling fuch prin- 

 ciples as relate to the matttr in contemplation. We 

 can guefs at the future only from the pail. As when 

 certain appearances happen, we remember, that the 

 "fame apppearances were formerly attended with cer- 

 tain ccnfecjuences ; the whole event is therefore pre? 

 fented to our minds, though not yet completed. The 

 great difficulty is, to recollect accurately in what par- 

 ticular circuraflances the prefent matter, agrees with 

 the pall, and the degree of probability will be in ad 

 exact proportion to the circumftances in which they 

 agree. 



* Hartley on Man, Prop. 38. 



Thus 



