The first great skeptical philosopher of the ancient world was Pyrrho of Elis (circa 310–270 B.C.). After traveling with Alexander the Great as a court philosopher, Pyrrho returned home to teach great crowds of admirers and seekers. He was known for presenting philosophy as a way of life that aims at a calmness of the spirit and happiness of the heart.
Pyrrho believed that people should always be quick to question and slow to believe. He seemed to think that we too easily become convinced of things that trouble our minds and disturb our souls. So he practiced, and preached, withholding judgment as much as possible.
Some stories from the ancient world portray Pyrrho as far too calm, and even indifferent, concerning dangers in his daily environment. We are told that his friends were constantly saving his life, pulling him from the paths of speeding carts, from the edges of cliffs, and from other dangers. Commentators ascribe this to Pyrrho's skeptical disinclination to trust appearances, and thus to a philosophical disinclination actually to believe anything that appeared to be going on around him. Appropriately enough, many people are skeptical about such stories.
Other stories about Pyrrho seem more credible, and more likely attributable to his skepticism. We are told that he was once attacked by a fierce dog, that he reacted with fear, and that he later apologized to his friends for not acting consistently with his own philosophy. Another story does have him attaining this consistency of withholding judgment and experiencing inner calm as a result. He was on board a ship during a violent storm, but showed no fear. His terrified fellow passengers asked how he remained calm. We are told that, in the midst of the storm, he pointed to a little pig on deck calmly eating his food, and said that this is the unperturbed way a wise man should live in all situations.
Another ancient skeptic was the physician Sextus Empiricus. Appropriately enough, we are uncertain of the place and date of his birth, the date of his death, and where he lived. He seems to have lived in the second half of the second century A.D. and into the first quarter of the third century. We think he was Greek because of his facility with the Greek language and apparent knowledge of places in the Greek world. His works have been very influential and are the best sources for the arguments and positions of classic Greek skepticism.
Like Pyrrho, Sextus was no dogmatic naysayer about human knowledge. He didn't deny its possibility or actual occurrence. He was just extremely careful about committing belief to anything that went beyond immediate appearances and urged us on to similar caution.
Skeptics like Pyrrho and Sextus thought that we should live our daily lives in accordance with appearances, but that we should refrain from drawing any conclusions from those appearances as well as from holding any firm beliefs based on those appearances. The point of this caution was always the goal of unperturbedness of spirit, and ultimately a sort of peaceful happiness of life.
This is the ancient heritage of skepticism. But our use of skeptical questioning today is a bit different. We do not aim at the attainment of spiritual calmness but rather at intellectual enlightenment.