Adam Hochschild is the author of “King Leopold’s Ghost: A Story of Greed, Terror, and Heroism in Colonial Africa.”

NEWT GINGRICH seldom misses a chance to note that he is a historian. He lards his speeches with references to obscure events in the American past, talks about his time teaching at West Georgia College (not one of those effete Ivies), and has declared that the more than $1.6 million in fees he earned from Freddie Mac was for his work not, heaven forbid, as a lobbyist, but as a historian. And last year he was in the news for saying President Obama exhibited “Kenyan, anticolonial behavior.”

Mr. Gingrich would be our first president with a Ph.D. since Woodrow Wilson. Does his work as a historian tell us anything about him? Or, for that matter, anything about why, despite certain events in 1776, he considers “anticolonial” an epithet? To address these questions, a good place to start is his 1971 Tulane doctoral dissertation: “Belgian Education Policy in the Congo 1945-1960.”

A curious document it is — but not in ways that Mr. Gingrich’s enemies might hope for, since the dissertation is not filled with racism or drum-beating for colonialism’s glories.... The writer who emerges from the text is not the fire-breathing, slash-and-burn partisan attacker Mr. Gingrich’s critics portrayed from his time as House speaker, nor the profound, big-picture thinker Mr. Gingrich the candidate presents himself as. It’s the desk-bound policy wonk....

Woodrow Wilson’s Ph.D. dissertation boldly asserted that the founding fathers had gotten many things wrong, and advocated for this country something like the British parliamentary system. Soon published as a book, it was argued over for decades, and even scholars who disagreed with Wilson respected him, and his openness to changing his ideas. Mr. Gingrich may succeed in being elected president, but it is hard to imagine him, like Wilson after he left the White House, being elected president of the American Historical Association.