A few years ago I was contacted by a self-described skeptic seeking counsel. He was in a sorry state, epistemically speaking. Indeed, he doubted that he had any knowledge at all and was seeking aid in terms of a refutation of his skepticism. He was troubled by his deep and abiding doubts and was seeking deliverance.
I began with a diagnosis. I observed that he had begun with a Cartesian assumption that knowledge required certainty. Once there, he had quickly discovered what philosophers call the “Cartesian circle,” a term that refers to the fact that those who begin with Cartesian assumptions can never attain the certain knowledge required to refute skepticism.
So what to do?
Since meeting the demand of certainty was not an option, I suggested a very different course of treatment: the skeptic should begin by turning his skeptical eye back on his initial assumption that knowledge requires Cartesian certainty in the first place. And so, I asked him, “Why are you more convinced that you know knowledge requires certainty than that you have two hands or that 2+2=4?” In short, it seemed like he was granting an undeserved conviction to the assumption that knowledge, by definition, requires certainty. Why believe that?
“Indeed,” I continued, “it seems to me that your analysis is self-refuting. You see if you could be wrong in believing that 2+2=4 then surely you could also be wrong in believing that knowledge requires certainty. Thus, if that possibility is sufficient to suspend belief in 2+2=4, then it is likewise sufficient to suspend belief in the claim that knowledge requires Cartesian certainty. But look at what then happens: once you suspend belief in that certainty demand, you get back your belief in 2+2=4 and that you have two hands, and most of your other mundane beliefs. In short, The Cartesian dragon has been slain!”
So how’d that work? Sadly, not as well as I had hoped. He nodded thoughtfully and we parted ways soon after. But months later I learned that he was still wrestling with that same skepticism. The problem, I suspect, is that he found himself doubting my analysis — and perhaps even that I existed in the first place to give it.
The Cartesian circle, it would seem, had won.