Nicomachean Ethics

On ἐπισπήμη, from I. Post. Analyt. chap. i. and ii.

(Such parts only are translated as throw light on the Ethics.)

All teaching, and all intellectual learning, proceeds on the basis of previous knowledge, as will appear on an examination of all. The Mathematical Sciences, and every other system, draw their conclusions in this method. So too of reasonings, whether by syllogism, or induction: for both teach through what is previously known, the former assuming the premisses as from wise men, the latter proving universals from the evidentness of the particulars. In like manner too rhetoricians persuade, either through examples (which amounts to induction), or through enthymemes (which amounts to syllogism).

CHAP. II

Well, we suppose that we things (in the strict and proper sense of the word) when we suppose ourselves to know the cause by reason of which the thing is to be the cause of it; and that this cannot be otherwise. It is plain that the idea intended to be conveyed by the term is something of this kind; because they who do not really know suppose themselves thus related to the matter in hand and they who do know really are so that of whatsoever there is properly speaking Knowledge this cannot be otherwise than it is Whether or no there is another way of knowing we will say afterwards, but we do say that we know through demonstration, by which I mean a syllogism apt to produce Knowledge, i.e. in right of which through having it, we know.

If Knowledge then is such as we have described it, the Knowledge produced by demonstrative reasoning must be drawn from premisses and , and , and , and , and , for so the principles will be akin to the conclusion demonstrated.

(Syllogism, of course there may be without such premisses, but it will not be demonstration because it will not produce knowledge).

, they must be, because it is impossible to know that which is not.

, that is indemonstrable, because, if demonstrable, he cannot be said to them who has no demonstration of them for knowing such things as are demonstrable is the same as having demonstration of them.

they must be, and , and in time, , because we then know when we are acquainted with the cause, and , if causes, and , not merely comprehended in idea but known to exist (The terms prior, and better known, bear two senses for and are not the same, nor , and I mean, by and , such things as are nearer to sensation, but abstractedly so such as are further Those are furthest which are most universal those nearest which are particulars, and these are mutually opposed.)

And by , I mean , for principle means the same as first And the principle or first step in demonstration is a proposition incapable of syllogistic proof, one to which there is none prior. Now of such syllogistic principles I call that a θέσις which you cannot demonstrate, and which is unnecessary with a view to learning something else. That which is necessary in order to learn something else is an Axiom.

Further, since one is to believe and know the thing by having a syllogism of the kind called demonstration, and what constitutes it to be such is the nature of the premisses, it is necessary not merely to , but to , either all or at least some of, the principles, because that which is the cause of a quality inhering in something else always inheres itself more as the cause of our loving is itself more lovable. So, since the principles are the cause of our knowing and behoving we know and believe them more, because by reason of them we know also the conclusion following.

Further: the man who is to have the Knowledge which comes through demonstration must not merely know and believe his principles better than he does his conclusion, but he must believe nothing more firmly than the contradictories of those principles out of which the contrary fallacy may be constructed: since he who , is to be simply and absolutely infallible.

BOOK VII