Keith Hennessey served as director of George W. Bush National Economics Council from 2007 to 2009. And he wants you to know that Bush was a very smart man. Smarter than Hennessey. Smarter than the students at Stanford. Almost certainly smarter than you.

I'm inclined to agree, actually. You don't get to be president without being pretty smart. And Hennessey's story that Bush was smarter in private than he seemed in public is echoed by others who met one-on-one, or in small groups, with the 43rd President. In an interview with Playboy, for instance, New York Times columnist David Brooks says Bush "was 60 IQ points smarter in private than he was in public. He doesn’t want anybody to think he’s smarter than they are, so puts on a Texas act. It becomes so deep, it’s part of him now. I’ve rarely seen a person whose off-the-record manner is so different from his on-the-record manner.”

But all this just goes to show that raw intelligence is overrated. Bush was smart. Plenty of the people around him were smart. But he was a bad president. Presidential scholars rank him 38th -- and, remember, there have only been 43 presidents (Barack Obama is the 44th, but his term isn't up yet). He left office with dismal approval ratings, though he's since rebounded from unbelievably unpopular to merely unpopular.

No industry on earth had the IQ-scores-per-capita of the financial industry in 2007. And we saw how that turned out. To see Bush's failures -- or Wall Street's failures -- as a failure of insufficient intelligence is comforting, but very wrong. These are stories about how smart people can lead themselves and others down the wrong paths. To a large degree, they wouldn't be able to do it if they weren't smart, but that just proves that not all mistakes are dumb, and that being smart isn't the same thing as being wise, right or capable.