Chap. XX. A N T I E N T METAPHYSICS; 295 



to the nature of things, but the opinions of men. In this (snCe we 

 fay, that a thing is necejfary^ which happens conftantly and regularly, 

 without one inftance to the contrary. Of this kind is the defcent of 

 heavy bodies, the afcent of flame, the rifing or letting of the fun; for 

 thefe things, we know from experience, happen conftantly and uni- 

 formly : And, it is by experience and induction only, not ^ priori^ 

 that we know any thing of the qualities of natural things ; and there- 

 fore thefe events are nccejfary in a fenfe very different from that in 

 which we fay that the theorems of fcience are neceffary truths. Con- 

 tingent^ on the other hand, is that which does not happen conftantly 

 and regularly. Of this kind antient philofophy has diftinguilhed 

 three different fpeciefes ; for either the event happens more frequently 

 one way than another, and then it is faid to be %yri r« x«xv; of this kind 

 are the regular productions of nature, and the ordinary adions of men: 

 Or it happens more rarely, fuch as the birth of monfters, or other ex- 

 traordinary productions of nature, and many accidents that hap- 

 pen to man : Or, lafily^ it is betwixt the two, and happens as often the 

 one way as the other ; or, as they exprefs it in Greek, ixcn^ ijv^i. Of 

 this kind are fome things in nature, fuch as the birth of a male or fe- 

 male child ; a good or bad day in fome climates of the earth ; and many 

 things among men, fuch as good or bad luck at play. All thefe laft 

 mentioned events are in reality as neceffary as thofe firft mentioned, 

 fuch as the falling of heavy bodies, &c. But, as they do not happen 

 conftantly and uniformly, and, as we cannot account for their hap- 

 pening fometiines one way and fometimes another, we fay they are 

 contingent. 



GH AP. 



