In a fictional high school in the Ohio suburbs, a teacher’s question about a number pattern sparks a dialogue with a student that “look[s] under the hood of reason itself.” In an article for Nautilus, author Simon DeDeo, a professor of social and decision science at Carnegie Mellon University, tours concepts like pattern, simplicity, beauty, and universality over the course of the conversation between teacher and student, who ultimately use reason to question reason's own relationship to truth.

Read the dialogue, “Ian and the limits of Rationality,” in Nautilus (September 22, 2021)



Teacher: I don’t doubt, Ian, that you’re clever enough to come up with any extension of the pattern you like. And I admit that we do have a list of things we want you to know, that the prime number sequence is on that list, and you and I both agree it’s the best match from that list.

Practically, we need to evaluate your ability to remember what we want, and we like to make things a bit tricky because one day your boss will want you to read his mind in roughly the same way. Welcome to the real world.

But the real reason, if we were to get into it—and, honestly, I’d rather not—is that my rule is better than your rule because my rule is simpler. It’s short, it’s easy to tell someone. It’s elegant. And so if you were to somehow encounter the first few terms of this sequence in the real world—say, in the crash log for a computer program you wrote, or a list of cicada generation times—you’d do far better to think about whether it’s to do with primes, than with your elaborate construction...