EconTalk · Russ Roberts

A Mind-Blowing Way of Looking at Math (with David Bessis)

October 27, 2025·1 hr 22 min·5 clips

Mathematician David Bessis confesses that math books are not meant to be read—they're devices for calibrating intuition.

Russ Roberts opens with an unusually direct pitch. Whatever else happens in the interview, he wants listeners to read David Bessis's Mathematica, a book he says he has read twice. The praise is plain and strong. Then the conversation turns to a stranger question: what does it mean to know something mathematically before you can explain it? Bessis brings up aphantasia. A reader who could not make mental images still knew that a straight line sweeping across a circle could not cross it at three different points. That example does useful work. It pushes back on the easy idea that intuition is just a picture in the head. For some problems, Bessis says, the visual cortex may help. But mathematical certainty can also arrive as a nonvisual sense that the answer has to be so. Roberts then steers the discussion toward Kahneman's System 1 and System 2, and asks why that familiar contrast may need another layer. Some answers just appear. One plus one is two, and an elephant is bigger than a mouse, with no felt calculation. Other questions do not. Ask how many days ago you were born, and the method may be clear while the work still feels annoying. Bessis is not just sorting mental tasks into bins. He is trying to defend intuition without shrinking it into speed, imagery, or mental laziness. The ending turns uneasy. On AI and science, Bessis sees something powerful, hard to avoid, and maybe subtractive from work humans have treated as their own. Roberts lets that discomfort sit. Science may soon be impossible without AI, and people may not be ready for that dependence.

As heard by us

An exacting conversation about intuition, math, and how people know what they know.

Mathematics is treated less as formal technique than as a path into how the mind reaches certainty, with David Bessis arguing for a larger role for intuition than many readers were taught to permit.

Read the full review in PlayNext →

Why you'd press play

You want math to feel less like procedure and more like intuition.

Read the full recommendation in PlayNext →

Listen to the show on

Apple Podcasts Spotify

Play clips from this episode More from EconTalk