5^ ANTIENT METAPHYSICS. Book 11. 



and from which they are, by us, abftracted. But, in the language of 

 Plato, and the Pythagorean fchool, they are called fimply ideas, 



Thefe ideas are, if I miftake not, thtfiibjiantial or eljential forms of 

 the Peripatetics, fo much exploded, and even ridiculed by our modern 

 philofophers, but which 1 think muft neceflarily have an exiftence, 

 not only in the mind of the Deity, where all things exift, but in every 

 natural fubftance ; tho* 1 hold it to be impoflible that we can have any 

 direct or immediate comprehenfion of them, any more than we have 

 of the matter of fuch fubftances. But, as we can have fome idea of 

 ihef?iatter from analogy *, fo, in the fame manner, we may have fome 

 notion of this i7itenialform^\^\\\di conftitutes the effence of all natural 

 fubftances; and this notion we derive from the analogy of our own ideas, 

 which we form by abftradion from material fubftances. By this opera- 

 tion of the mind, we create a fpecies of beings, the ejftntial forms of 

 which we perfedly know ; whereas, the effence of the works of God 

 we can never perfedly know in this ftateof our exiftence. For example, 

 the effence of any material triangle, whether of earth or ftone, or of 

 whatever other matter, I never can know ; but when, from the earth or 

 ftone I abftrad the figure of a triangle, and form the idea of it without 

 the matter ; of this being, thus created by myfelf, I know perfedly 

 the efl'ence, and define it to be ' a figure bounded by three lines.'* 

 This is the eflential form of a triangle, from which all the properties, 

 that Euclid has demonftrated of it, refult. Now, in the fame manner, 

 I fay, that, of every natural fubftance, every animal^ for example, and 

 njegetable^ there is a form, from which refult all the properties of this 

 animal and vegetable, fuch as fgure^ fize, colour^ &c. ; all which are 

 perceptible by our fenfes ; but the internal form^ from which they all 

 refult, is not perceptible by our fenfes, nor even by our underftand- 

 ing, diredly and immediately, nor otherways than by the analogy I 

 have mentioned. 



Another 



* See the preceding chapter. 



