DiFFERENTSYSTEMS. (>^ 



fenfations be real or imaginary, whether they 

 exifl; without or within, whether it be God or 

 matter that we every wheie behold, is to us of 

 little importance : We are not lefs certain of 

 being uniformly aifeded in the fame manner 

 by the fame caufcs. The relations between our 

 fenfes and the obje<3:s which affedt them are 

 neceflary and invariable. It is upon this bafis 

 alone that the principles of philofophy ought 

 to be founded, otherwife our knovv'ledge mud 

 be ufelefs and fallacious. Can an harmonic 

 triangle create the fubftance of the elements \ 

 Is fire, as Plato afErms, an acute triangle, and 

 light and heat two properties of this triangle ? 

 Are water and air redtangular and equilateral 

 triangles ? Is the form of the element of earth 

 a fquare, becaufe, being the leaft perfect of 

 the four elements, it recedes as far as pofTible 

 from a triangle, without departing altogether 

 from its elfence ? Do males and females em- 

 brace each other for no other purpofe but to 

 complete the triangle of generation? Thefe Pla- 

 tonic ideas have two different afpeds : In fpe- 

 culation, they feem to proceed from fublime 

 principles; but the application of them in prac- 

 tice leads to nothing but falfe and childifh con- 

 clufions. 



Is it difficult to perceive that our ideas origi- 

 hate from our fenies alone; that the objecfts wd 

 regard as real exiflences are thofe concerning 

 Ifvhich the fenfes uniformly give the fame tefli-^ 



E 2 monyj 



