Being Wrong - Kathryn Schulz [82]
So certainty is lethal to two of our most redeeming and humane qualities, imagination and empathy. It is ridiculed by philosophers as intellectually indefensible. (Voltaire called it “absurd,” and Bertrand Russell disparaged it as “an intellectual vice.”) It is widely excoriated as (in the words of the writer Will Durant) “murderous.” When we ourselves observe it in others, we find it laughable at best, despicable at worst. This is a singularly ugly portrait. So why do we continue to find certainty so attractive?
Imagine for a moment that a man is hiking in the Alps when he suddenly finds his progress blocked by a narrow but terrifyingly deep crevasse. There’s no safe passage around it, and he cannot retreat the way he came. The question, then, isn’t what the man should do; his only option is to leap over the chasm. The question is how he should feel about doing it.
This hypothetical scenario was devised by William James to help us think about the merits of certainty. While most of his fellow philosophers were criticizing it as intellectually untenable or morally repugnant or both, James decided to come to its defense. Or rather, to its partial defense: he, too, worried about the potential moral consequences of certainty—but, ever the pragmatist, he argued that it had also some distinct practical advantages. However intellectually honorable doubt might be, he pointed out, it would clearly serve our hypothetical hiker poorly. The better option would be for him to believe absolutely in his ability to leap over the crevasse.*
James meant by this that shaky ground should not always deter us from unshakable faith. There are countless instances when our own lives or the larger world have been changed for the better by a passionate conviction: that you can lower your cholesterol or get into medical school or secure a better future for your children; that polio can be eradicated or that the wilderness can be protected or that people with disabilities should not be prevented from rich and full participation in public life. As James put it, sometimes unswerving beliefs “help to make the truth which they declare.”
In these situations, certainty is the best choice because doubt is a bad one—counterproductive at best, dangerous at worst. But there are also occasions where certainty is the best option because doubt isn’t really an option at all. This was the (again, partial) defense of certainty offered by the philosopher Ludwig Wittgenstein. In the face of those of his colleagues who believed that certainty was intrinsically absurd, Wittgenstein argued that, sometimes, it is uncertainty that doesn’t make any sense. If we want to get through life in a functional fashion, he noted, we have no choice but to treat some of our beliefs as absolutely certain. These beliefs serve as a kind of bedrock on which to build the rest of our worldview; instead of questioning them, we use them to ask and answer all our other questions. “At the foundation of well-founded belief,” Wittgenstein wrote, “lies belief that is not founded.” Not ill-founded, mind you: just not founded at all.*
As an example of such a belief, Wittgenstein takes his conviction that he has two hands. This was the most extreme example he could have chosen, for the same reason that anosognosia is the most extreme example of error: because beliefs about our bodies are essentially immune to doubt. For this and other bedrock beliefs, he argued, we literally can’t provide any convincing grounds, because the belief itself is “as certain as anything that I could produce in evidence for it.” If someone were to ask him how many hands he had, Wittgenstein pointed out, “I should not make sure by looking. If I were to have any doubt of it, then I don’t know why I should trust my eyes. For why shouldn’t I test my eyes by looking to find out whether I see my two hands?” In this case and many others like it, he argued, it is doubt that is the absurdity, and certainty that is the only reasonable option.