Chap. X. ANTIENT METAPHYSICS. i% 



figures our fenfe perceives nothing, except that they limit or bound fo 

 much of the furfice on which they are irifcribed. But, to have the 

 idea of a triangle, we muft know that it is bounded by three lines: 

 And we cannot have the idea of a fquare, without knowing that it 

 is bounded by four equal lines, forming as many right angles. 



In this manner we form the particular idea of any objed prefent- 

 cd to us by our fenfes. And, the next ftep, in the progrefs of our 

 ideas, is to abftrad: the idea, thus formed, from the body in which it 

 is inherent, and to form an idea of it feparated from that body. 

 And this operation of the mind fhows, that the firft ftep in form- 

 ing thofe ideas, is conceiving them as inherent in the body: For 

 otherwife they could not be abftraded from it ; fo that there 

 would be no fuch thing as an abfirac^t idea, which all the authors, 

 who treat of ideas, and Mr Locke among the reft, admit have a 

 real exiftence. 



The third ftep in the progrefs is to form what is called a general- 

 idea. And this is done by obferving, that other objeds of fenfe have 

 the fame peculiar or diftinguiftiing qualities, that we have obferved 

 in the fingle object, of which we have formed the particular idea : 

 Which qualities when we apply to thefe other objeds, we form 

 'what is called 2i general idea. 



The firft general ideas muft neceflarily be of fpeciefes, and of the 

 loweft fpeciefes, which have nothing below them but individuals. 

 And this is neceflary, our firft ideas being, as I have fhown, of in- 

 dividual things. From the fpecies our ideas rife to the genus, as 

 from our idea of the fpecies man or horfe^ w^e rife to the genus, 

 animal', and from a lower genus we afcend to a higher ; and io on 

 from lower to higher, till we come to the higheft genufcs of all, that 

 is the categories. 



Vol. V. Y Thus 



