398 ANTIENT METAPHYSICS. Book V. 



CHAP. IV. 



When the Propofttion is notfelf-evident^ then there muft he the Difcurfus 

 Mentis in order to prove it — l.he Nature of this Dilcurfus — All the 

 Difcurfus, houuever various^ reducible to the Syllogiflical Form — De- 

 finition of Syllogifm — For?n of the SyllogiJt7i explained by Arijlotle in 

 his firft Analytics — The Analyfis there mofl ^wonderful — Syllogifm 

 may he perfetl in its Fornix and yet the Conclifion may he jalfe^ dubiousy 

 or certain^ according to the Nature of the PremiJJes — What makes 

 the Syllogifm demonjlrative explained by Ari/lotle in his laft Analytics 

 ^—The Method obferved by Arijlotle in that great Work — The Nature 

 of Demonflration — Definition as necefjary for it as Axioms — Tiva 

 Kinds of Demonflration — the one dire(St — the other indiredl — or ex 

 abfurdo — 27?^ Difference hetivixt Analyfis and Demonftration — A" 

 nalyfis the Method of Difcovery in all Sciences — Similitude betwixt the 

 analytical Reafoning and the Demonf ration ex abfurdo — The Dialec- 

 tical Method of Reafoning dfferentfrom any yet mentioned — The Dia- 

 lectic of Arifotle quite different from that of Plato — Arijlotle* s Dia- 

 le£lic much praSiifed before his Time — but only reduced to an Art by 

 him — Nature of this Kind of Reafoning illujl rated by Examples, 



IF the mind do not perceive intuitively the connection betwixt the 

 praedicate and fubjc(ft, as in the cafe of axioms, or felf-evi- 

 dent propofitions, it can do it no otherwife than by the intervention 

 of other ideas, or by the ufe of middle terms, as they are called 



in 



