Who Is the Greatest Modern-Day Thinker?

The e-mail gods recently delivered this interesting query from a reader named Derek Wilhelm:

I go to the University of Richmond, which requires [us] to take a class called Core, where we read famous historical books. (Gandhi, Marx, Plato, Augustine, just to name a few). Anyway, my question for you is: Who do you think is the greatest modern-day thinker?

I love this question. It first requires you to define what a “thinker” is, and also raises the question of what incentives exist in the modern world to be a thinker. Also, is someone a great thinker if they’re never able to communicate their thoughts to a broad audience?

On a related note: The Times recently ran a piece about a rise in college philosophy majors; interestingly, the Wall Street Journal published a piece shortly thereafter (sorry, can’t find a link, but here’s a reprint of the pertinent info) ranking the first-year salaries for 16 selected college majors: engineers were first (at $48,707) and philosophers were dead last (at $28,234).

Once you’ve thought about what it means to be a thinker, then comes the hard part of thinking about who best fits the description.

So who are your nominees, and why?