First steps: Skepticism

The Skeptics believed you could never be completely certain of the truth. For example, you can't really know what objects really are, only how they appear. Your senses could be fooling you. Pyrrho is considered to be the first skeptic philosopher, and his ideas were expounded by a philosopher with the unlikely name of Sextus Empiricus.

I first heard of Sextus Empiricus when I was reading “The Black Swan” by Nassim Taleb, and I thought he was making it up. That book does have fictional interludes in it, so it was possibly an invention. But I have found other references to this character, so I am now of the opinion that he did exist. Of course I couldn't be certain of this and still be a good skeptic.

Another Skeptic was Carneadus, and his brand of skepticism is known as Academic Skepticism, since he taught at the Academy in Athens. It appears that Skeptics spent most of their time trying to debunk the ideas of other philosophers, especially the Stoics, although Carneadus also took on the Epicureans.

I like the story of Carneadus's trip to Rome, where on one day he delivered an oration praising Roman justice, and the next day he refuted his own arguments and concluded that justice was impossible. The Romans didn't bother trying to argue with him, they just sent him back to Athens, where he could no longer confuse them with his philosophy.

Here's an overview article about Skepticism. Returning to Sextus Empiricus, he introduced ideas of empiricism to this philosophy. If you couldn't be certain of anything, at least you could have provisional beliefs. Then you could collect evidence for or against your beliefs. Sextus was a physician as well as a philosopher, and belonged to the empirical school of medicine, which believed in basing medical practice on experience. Given the state of medical theory at the time, this was probably a good idea.

To me, Skepticism seems less like a complete philosophy, and more like a useful tool, a way to think about and criticize ideas. In this way it resembles pragmatism. I find it interesting to introduce the idea of uncertainty into discussions about ethics. How can you find the correct way to act in a particular situation when you can't be completely certain of the facts of the matter, or even of the ethical principles that you believe in?