Professor of Geology, Harvard University

Most overrated:

I nominate the general category of people who became icons for patriotic phrases but played no palpable role in our history. I’m sure that Nathan Hale was a fine young man, and I regret that he had to give up his one life, but nothing would be different (beyond a pious pronouncement memorized by generations of schoolchildren) if he had never lived.

Most underrated:

So much so that we do not even know his name. I nominate whichever early European settler first brought smallpox to the New World. Our conquest of the indigenous Indians may have been inevitable by dint of firepower (and racist ideology), but imperial expansion has been moved forward far more efficiently by disease than by the Maxim gun.