1. We should distinguish two kinds of knowledge, knowledge of fact and knowledge of reasons, where what the reasons account for are the facts.
2. Knowledge proper involves both facts to be accounted for and reasons which account for them; for this reason Socrates claimed to know nothing; when we start to research, we may or may not be familiar with many facts, but whether this is so or not we cannot tell until explanations and reasons begin to become available.
3. For explanations and reasons to be available, they must derive ultimately from first principles, but these first principles do not come ready-made; they have to be devised by the inquirer, and how this is done itself needs explanation.
4. It is not done in one fell swoop; at any given stage researchers build on the work of their predecessors right back to their earliest predecessors who are lay inquirers. Such progressive scrutiny is called

"dialectic," starts with the ideas of the Many and ends (if it ever ends) with the ideas of the Wise.

1. Among the methods used in dialectic (or "argumentation") is system-building, which in its turn involves higher and higher levels of abstraction. So first principles will be, roughly speaking, the smallest and most conceptually economical principles which will account for the data which the theory has to explain.
2. The progress toward an acceptable body of first principles is not always tranquil; disputes, paradoxes, and obstructions to progress abound, and when they are reached, recognizable types of emendation are called upon to restore progress.
3. So the continuation of progress depends to a large extent on the possibility of "saving the phenomena," and the phenomena consist primarily of what is said, or thought, by the Wise and, before them, the Many.