Failure to appreciate the value of uncertainty is at the origin of much silliness in society. Are we sure that the Earth is going to keep from heating up if we don’t do anything? Are we sure of the details of the current theory of evolution? Are we sure that modern medicine is always a better strategy than traditional ones? No, we are not, in any of these cases. But if, from this lack of uncertainty, we jump to the conviction that we had better not care about global heating, that there is no evolution and the world was created six thousand years ago, or that traditional medicine must be more effective than modern medicine — well, we are simply stupid. Still, many people do make these inferences, because the lack of certainty is perceived as a sign of weakness instead of being what it is — the first source our knowledge.
Physicist Carlo Rovelli on “The Uselessness of Certainty” in This Will Make You Smarter