Retired neurosurgeon Ben Carson, already under fire for his foreign policy acumen, is now being criticized for his grasp of history, particularly that of Thomas Jefferson.

In a C-SPAN interview broadcast Sunday, Carson praised Jefferson as a Founding Father who “tried to craft our Constitution in a way that it would control peoples’ natural tendencies and control the natural growth of the government.”

Jefferson, however, did not participate in the development of the U.S. Constitution during a 1787 convention. As Carson himself pointed out in his book A More Perfect Union, Jefferson was serving as U.S. minister to France at that time.

The Washington Post, which reported on Carson’s flub, also noted that “it’s not the first time Carson has abused Jefferson’s history.” The Post reported:

“Thomas Jefferson himself said, ‘Gun control works great for the people who are law-abiding citizens and it does nothing for the criminals, and all it does is put the people at risk,’” he told Fox’s Neil Cavuto after the shootings at Umpqua Community College in Roseburg, Ore. in early October. Jefferson never said that.

The supposed Jefferson comment on gun control is listed among many “spurious” quotations by the Monticello Web site. “This is not something Jefferson wrote,” say the researchers at Monticello, but rather comes from a passage he included in his “Legal Commonplace Book.” The passage, they note, was written by Cesare Beccaria in his “Essay on Crimes and Punishments” and was copied by Jefferson.

Oddly, Carson’s footnote to the quote duly notes that it comes from Beccaria and not Jefferson.