These concluding paragraphs from a review by Lloyd Gerson of a recent exploration of relativism in ancient Greek philosophy (by Mi-Kyoung Lee) seem to me quite important. And they show something of the 'cash value' of Gerson's approach (discussed in some earlier posts on this blog):
The principal strength of this fine book is the meticulous
reconstruction of the epistemological views of Protagoras and
Democritus. The principal weakness of the book is owing to the fact
that Lee is also or especially concerned to explore the engagement with
Protagoras and Democritus by Plato and Aristotle. Not unreasonably, she
does this based on the hypothesis that an undercurrent of skepticism
was to be found among the ideas of the two Presocratic giants. The
problem with this is that both Plato and Aristotle criticize their
predecessors based on their own firm views about what knowledge is and
their convictions that the Protagorean and Democritean approaches
cannot attain it. Plato holds that knowledge is exclusively of
separate, intelligible reality; Aristotle holds that knowledge is
exclusively of what "cannot be otherwise." How these two views are
related is another story. But the criticism of Protagoras and
Democritus -- which is what this book is to a significant extent about
-- comes from these perspectives.
Lee does not say much about the views of knowledge that generate the
criticism. Admittedly, a thorough exposition of these is the subject of
one (or more) additional books. Yet without a more explicit discussion
of these views, the criticism of the skeptical tendencies in Protagoras
and Democritus is rather captious. One way to defeat a skeptic or to
disarm her is to agree that there is such a thing as knowledge and to
insist that the word "knowledge" is merely to be applied stipulatively
according to whatever socially rooted criteria happen to be convenient.
To be a skeptic about knowledge thus construed would indeed be foolish.
This way of dissolving the skeptical challenge has always been
attractive to some philosophers. But it is not the way followed by
Plato or Aristotle. Lee's book would have been even better if she had
taken seriously Sextus' remark to the effect that if skepticism can be
made to prevail, then Greek pretensions to wisdom will be unmasked for
what they are. Plato and Aristotle took skepticism as seriously as did
Sextus and for exactly the same reasons.