Lecture notes for reading: Stanford Enclyclopedia of Philosophy 'Aristotle' §§1-5, First published Thu Sep 25, 2008: substantive revision Tue Aug 25, 2020

These notes were produced by cutting and pasting the text from the article, then turning that into lecture notes. There are passages remaining that are verbatim from that article, but it has been condensed and turned into outline form so we can review it efficiently in class. Cluttering up the notes with quotation marks every time the exact wording of the article is retained would be counter-productive because it would reduce clarity. Know therefore that there is a fair lot of verbatim language below from the article.
The titles in this list are those in most common use today in English-language scholarship, followed by standard abbreviations in parentheses. For no discernible reason, Latin titles are customarily employed in some cases, English in others. Where Latin titles are in general use, English equivalents are given in square brackets.

“Human beings began to do philosophy,” he says, “even as they do now, because of wonder, at first because they wondered about the strange things right in front of them, and then later, advancing little by little, because they came to find greater things puzzling” (Met. 982b12).

"As in other cases, we must set out the appearances (phainomena) and run through all the puzzles regarding them. In this way we must prove the credible opinions (endoxa) about these sorts of experiences—ideally, all the credible opinions, but if not all, then most of them, those which are the most important. For if the objections are answered and the credible opinions remain, we shall have an adequate proof." (EN vii 1, 1145b2–7)
Once you have surveyed our work, if it seems to you that our system has developed adequately in comparison with other treatments arising from the tradition to date—bearing in mind how things were at the beginning of our inquiry—it falls to you, our students, to be indulgent with respect to any omissions in our system, and to feel a great debt of gratitude for the discoveries it contains. (Soph. Ref. 184b2–8)
‘That from the earliest times logic has traveled a secure course can be seen from the fact that since the time of Aristotle it has not had to go a single step backwards…What is further remarkable about logic is that until now it has also been unable to take a single step forward, and therefore seems to all appearance to be finished and complete’ (Critique of Pure Reason B vii).
We think we understand a thing without qualification, and not in the sophistic, accidental way, whenever we think we know the cause in virtue of which something is—that it is the cause of that very thing—and also know that this cannot be otherwise. Clearly, knowledge (epistêmê) is something of this sort. After all, both those with knowledge and those without it suppose that this is so—although only those with knowledge are actually in this condition. Hence, whatever is known without qualification cannot be otherwise. (APo 71b9–16; cf. APo 71b33–72a5; Top. 141b3–14, Phys. 184a10–23; Met. 1029b3–13)

Some people think that since knowledge obtained via demonstration requires the knowledge of primary things, there is no knowledge. Others think that there is knowledge and that all knowledge is demonstrable. Neither of these views is either true or necessary. The first group, those supposing that there is no knowledge at all, contend that we are confronted with an infinite regress. They contend that we cannot know posterior things because of prior things if none of the prior things is primary. Here what they contend is correct: it is indeed impossible to traverse an infinite series. Yet, they maintain, if the regress comes to a halt, and there are first principles, they will be unknowable, since surely there will be no demonstration of first principles—given, as they maintain, that only what is demonstrated can be known. But if it is not possible to know the primary things, then neither can we know without qualification or in any proper way the things derived from them. Rather, we can know them instead only on the basis of a hypothesis, to wit, if the primary things obtain, then so too do the things derived from them. The other group agrees that knowledge results only from demonstration, but believes that nothing stands in the way of demonstration, since they admit circular and reciprocal demonstration as possible. (APo. 72b5–21)

We contend that not all knowledge is demonstrative: knowledge of the immediate premises is indemonstrable. Indeed, the necessity here is apparent; for if it is necessary to know the prior things, that is, those things from which the demonstration is derived, and if eventually the regress comes to a standstill, it is necessary that these immediate premises be indemonstrable. (APo. 72b21–23)
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We had perhaps better consider the universal good and run through the puzzles concerning what is meant by it—even though this sort of investigation is unwelcome to us, because those who introduced the Forms are friends of ours. Yet presumably it would be the better course to destroy even what is close to us, as something necessary for preserving the truth—and all the more so, given that we are philosophers. For though we love them both, piety bids us to honour the truth before our friends. (EN 1096a11–16)