At Harvard I took both math and physics courses all the way through, but I knew which was my subject. In mathematics, any principle you learned was simply true: you could apply it anywhere you liked and you’d never reach a falsehood. In physics, that wasn’t enough. You had to have some kind of deeper understanding to see that this principle was appropriate here and that one could be applied there. It made me uneasy.

Forty years on, what kind of mathematician have I become? One whose pride is that he doesn’t apply principles blindly but guided by deeper understanding! Indeed, not long ago I published an essay on “Inverse Yogiisms” all about mathematicians’ habit of following rigorous logic to misleading, though mathematically valid, conclusions.

Which brings me to two thoughts. One is that maybe I could have been a pretty good physicist after all. The other is that as a physicist, maybe I would have been a little less distinctive.

[3 February 2019]