3S8 ANTIENT METAPHYSICS. Book V, 



never can underftand, as a phlloropher ouglit to underftand, the philo- 

 fophy of Mind, and the nature of Truth and Science. Thefe principles 

 are to be learned from Ariftotle's book of Categories, with the aflift- 

 ance of Porphyry's Introduction to that book, and of Ammonius*s 

 Commentary upon both the Introdudlion and the Book iifelf. There 

 are, I doubt not, Tome French or Englifh fyftems of logic which may 

 be of ufe to the reader ; but with thefe I am not much acquaint- 

 ed, nor defire to be more, becaufe I chufe to go to the fource it- 

 felf, being well aflTured, from what I know of them, that, if 

 they have not drawn from that fource, they have produced no- 

 thing that is valuable upon the fubjed. Not that I believe it to be 

 abfolutely impoffible, even as men are educated and live at prefent, 

 that our times fhould produce a great genius in philofophy ; but I 

 fay, that genius mufl: be taught, and by good maPiers ; and, that it is 

 impoffible, without fuch affiftance, for any mortal man to invent a 

 •whole fyftem of fcience. I think I may fay, without offence to any 

 modern philofopher, that Ariflotle had as acute and inventive a genius 

 in philofophy as any of them ; yet, I will venture to affirm, that, un- 

 lefs he had been taught, as he was, both by Socrates and Plato, and, 

 unlefs he had Rudied diligently, as it appears he did, the writings of 

 the more antient philofophers of the Ionic and Eleatic fchool, and of a 

 greater fchool than either of thefe, I mean the Pythagorean, from 

 which he took his book of Categories, the foundation of his 

 whole fyftem, he never could have difcovered the Syllogifm, (if 

 it be true that it is his difcovcry), nor produced that compleat 

 fyftem of logic to be found in his book of Categories, his firft 

 and fecond Analytics, his Topics, and his treatife of Sophifm, to 

 which the labours of all the ages fince his time have added no- 

 thing confiderable. Before him, many philofophers, no doubt, rea- 

 foned very well, and made great difcoveries; but they reafoned as the 

 women and children fpoke ; for, though women and children, who 

 have been well educated, may fpeak very well, they do it by mere ha- 

 bit, 



