monstrations is assumed that this is predicated of that, yet not that very thing, nor that of which there is the same definition, and which reciprocates. To both however there is the same doubt against him who demonstrates by division, and against the syllogism thus formed, why man will be an animal biped pedestrian, but not an animal and pedestrian, for from the things assumed, there is no necessity that there should be one predicate, but just as the same man may be both a musician and a grammarian.
Chapter 7
How then will he who defines show the essence of a thing, or what it is? for neither as demonstrating from things which are granted will he render it evident that when they exist, it is necessary that something else should be, for demonstration is this, nor as forming an induction by singulars which are manifest, that every thing thus subsists, from nothing subsisting otherwise; since he does not show what a thing is, but that it is, or is not. What remaining method is there? for he will not indicate by sense nor by the finger.
Moreover how will he show what it is? for it is necessary that he also who knows what man is, or any thing else, should also know that he is, for no one knows with respect to non-being that it is, but what the definition or the name signifies, as when I say "tragelaphos," it is impossible to
