Our own Morgan Meis in the excellent Radical Society:
The skeptic is generally portrayed as standing, on purpose, outside the normal flow of life. The skeptic refuses to assent to things that most people take for granted, perceiving the world through a protective lens of doubt and incredulity. The skeptic is the one who pauses just as everyone else jumps in.
The funny thing about this picture is that it characterizes an attitude almost exactly opposite to what some of the earliest skeptics actually proposed. For them, the most important thing to be skeptical about was the very tendency for human beings to worry about knowledge. Once you start worrying about whether you really know things or not, it sets off a whole chain of intellectual moves that, to the skeptic, get you nowhere. Skepticism is not about nay-saying and arch looks; it is about getting us back into the normal flow of life, with, perhaps, a renewed and deeper sense of how flowing that flow really is.
Sextus Empiricus was just that kind of skeptic. Phyrronian Inquiries, his most influential work, was probably written sometime in the second century AC and lost soon thereafter before being rediscovered during the Renaissance. Its influence since then has been, at best, subtle. Problem is, Sextus wasn’t always the clearest writer. Frankly, he wasn’t always the clearest thinker either. Phyrronian Inquiries is a pretty tiresome book after the first fifteen pages or so. Against the Mathematicians (the other major work we have from Sextus, a rambling polemic against all strains of academic thought in the late Hellenistic world) is downright unreadable garbage. Sextus’ brand of skepticism is exhilaratingly contemporary at times, as we shall see; but Against the Mathematicians reminds us that the obsessions of past ages can be impenetrable indeed.
More here.