Chap. IX. ANTI EN T METAPHYSICS. 459 



mojl general caufe ; fo that, if the proof be from a particular caufe^ 

 when there is one more general comprehending the /?(3r^zV«/(3r, it is 

 not demonftration properly fo called. 1 his he makes plain, not only 

 to thofe who have ftudied his logic, but to fuch as know a little of the 

 elements of geometry ; without which, it appears, that he thought no 

 man was capable of learning logic, or any other fcience. If a man, 

 fays he, only knows that an ifofceles triangle has its three angles equal 

 to two right angles, he has no fcience or demonftrative knowledge of 

 that propofition ; becaufe, though he may, no doubt, demonftrate that 

 an ifofceles triangle has its angles equal to two right ones, yet, if he 

 do not demonftrate it from its true caufe^ vizi the nature of the triangle 

 in general, he cannot be faid to know it fcientifically. Now, That all 

 triangles have their angles equal to two right ones, is the general 

 propofition. That one fpecies of a triangle, viz. the ifofceles, has this 

 property, is a particular propofition, comprehended under the general. 

 Now, I afk any geometer, Whether the caufe of an ifofceles triangle 

 having this property, is not, that all triangles have it ? or, as A- 

 riftotle has expreffed it. Whether it be not qua triangle, not qua 

 ifofceles triangle, that it has this property *? If fo, it is evident 

 that, at leaft in this inftance, the general propofition is the caufe 

 of the particular 'j and, for the fame reafon, it is fo, in every in- 

 ftance. 



Thus, it appears, not only from the authority of Ariftotle, but from 

 , the reafon of the thing, that, to fuppofe we have no idea of caufe and 



M m m 2 efe^y 



* See Analytica Pofteriora, lib. i. cap. 24. His words are, Etyxf ro h<rtv »^Uii 



tTTM^^eiy f«fl ri ic-cc-KiMi;, ec7^X^ y| T^cywvijv « alur^ in lerctrKiXi',, »i'ttov *i^if -^ ocvro, a (lege i) i 

 tioui tri Tg(y«v»». 'OAws ti, II ftev ^t>) e»T»j )J r^tyaiiov, tirx hiKyv(;ty, ovk av eo) «^o5"i<|<$. 



And, a little farther, he fays, E< ^ nvotu^ii *tsv ktt/ rvxx»yi7[A0i T»f ecirixc, hki io-j J~/« t«* 



T« K«d»/ot; V «iT<*rtge»' '•» yx^ y.xd' «VT» iTrce^^H t/, t«vt« «vt» «t/Ta( nnuf t« h x»ttX»Vf 



■XgUZOV ftlTtCV «Cg« T* KH$»XCV, 



