Jonathan Zimmerman: Newt Gingrich, Pseudo-Historian

Jonathan Zimmerman teaches history and education at New York University. He is the author of "Small Wonder: The Little Red Schoolhouse in History and Memory."

Who knew my profession could be so lucrative?

That was my bemused first reaction to Newt Gingrich admitting that he took $300,000from the mortgage giant Freddie Mac in exchange for his "advice as a historian." Now sources are reporting that his total fee might have been as high as $1.8 million, which is more than some historians will make in a lifetime.

But here's what you need to know about Gingrich: He's not a real historian. Sure, he's got a Ph.D. in the field, and yes, Gingrich has written more than 20 books. But when he left academia for Congress in 1978, he also left behind the most basic canons of our discipline: rigor and humility. Put simply, we're supposed to know what we're talking about. And when we don't, we're supposed to say so.

That's what I learned on my very first day of graduate school, almost a quarter-century ago. The world is infinitely complicated, a professor told us, and we'll only be able to study a very small slice of it. And even when we think we understand that tiny piece, someone else will come along to prove us wrong....