76 ANTIENT METAPHYSICS, Book II. 



natural philofophy, mechanics, and aftronomy, wc do not abflraa: 

 the Form from the Matter, but confider them both together. In 

 pure mathematics, indeed, we do abftratft and confider the Forms 

 bythemfelvcs without the Matter ; and it is only with refpea to 

 this fcience, that the antient philolbphers fpeak of Ideas of Abftrac- 

 tion *. It is therefore true, that Ideas are confidered in the Matter, 

 as well as ivithout the Matter ; and therefore Ideas, and abftrad 

 Ideas, are not fynonimous terms. It is true, however, that the 

 Mind mud have fome notion of the Form as diftind from the Mat- 

 ter, though not confidered as adlually feparated from it ; and it is 

 this that diftinguirties eflentially the Ideas of the Man from the Sen- 

 fations of the Brute, who has no notion, either of the Form or of 

 the Matter, and, confequently, is incapable of diftinguifhing them. 



2clo^ Ideas are not general only, as is commonly believed, but alfo 

 particular ; that is to fay, they arc not only perceived in many par- 

 ticulars, but in one particular, fuch as an animal or a vegetable. If, 

 therefore, there were but one thing of the kind, as fome of the an- 

 tients fuppofed the fun to be, which, therefore, they faid was 7nona- 

 dicy ftill we Ihould have an idea of it, though there were neither 

 genus nor fpecies to which we could refer it ; for, to generalize, is no 

 more than to make that reference, the Mind having perceived a like- 

 nefs betwixt particular things, and in that way forming the Idea of a 

 genus or fpecies. Nor is there any thing to hinder a fenfation being 

 generalized by the Mind's perceiving that the fame fenfation arifes 

 from many different things : But it will not therefore become an 

 Idea, unlcfs the Mind perceive fomcthing of the nature and eflence 

 of the fenfation which diftinguifhes it from every other fenfation. 



Thus, it appears, that, though generalizing be, no doubt, an o- 

 peration of the Intelled, which is given to Man but denied to the 



Brute, 

 • Plato, nowhere, as I remember, fpeaks of fuch Ideas ; but Ariflotle and his 

 commentators fometimes mention them, and fay that they are 5"/ «2«<gi«-6«{ j but 

 they only apply the term to mathematical entities, fuch as lines, figures, and num- 

 bers. 



