Chap. II. ANTIENT METAPHYSICS. 189 



ing abftraded and generalized, cannot become Ideas, I think it is as 

 evident, that, neither by feparating, compounding, or combining 

 them in any way, can they be Co transformed. 



But, it will be faid, that, though our Senfations are not themfelves 

 Ideas, they are the materials ouc of which the Mind makes them, 

 in the fame manner as an artift makes any piece of work out of 

 Timber, or Stone, or any other Material j and this I know is the 

 common opinion of thofe who derive all our Ideas from Senfa- 

 tion. 



But I (hould be glad to know how the Mind can operate upon its 

 Senfations, otherwiie than by abftrading, generalizing, feparating, or 

 compounding them ; and, if by none, nor all of thefe operations, no 

 Ideas can be produced, it is not to be conceived how Ideas are to be 

 made out of Senfations. — As to the woi-ks of art that are made out 

 of Stone or Metal, thefe materials only change their form, and the 

 piece of work produced is ftill Metal or ftone. But an Idea is not 

 a Senfation in any refpedt, but is as different from it as the Fonn of 

 the piece of work is from the Matter : And, as the Form has an o- 

 rigin quite different from the Matter, fo is the Idea derived from a 

 fource quite different from the Senfation. 



It is true, indeed, that, in this ftate of our exiftence, confined as 

 we are in this prifon of flefh and blood, we can have no Ideas with- 

 ■out imprefhons made upon that flefh and blood by external objeds. 

 But this is faying no more, than that our Mind at prefent cannot o- 

 perate without Senfations : But it will not from thence follow, that 

 'our Senfations are the Caiife of our Ideas ; for we muft diftinguifli 

 betwixt the Caufe and that without which the Cau/e cannot operate. 

 An animal cannot adt, or exert the fundions of the Animal Life, 

 without a certain degree of heat and moillure ; and yet heat and 

 moifture are not the Caufes of the Animal ading : I cannot fee an 



objedt, 



