(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 know 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 knowing 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 true and first, and incapable of syllogistic proof, and better known, and prior in order of time, and causes of the conclusion, 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).