Donald Trump has named Ben Carson as his nominee to head the Department of Housing and Urban Development, but we have to wonder why.

Carson is an accomplished neurosurgeon. He has no background in housing, construction, mortgages, urban planning or municipal government. It’s true that he’s black, and it’s true that he grew up in an urban environment in Detroit, Michigan. But there are millions of people who meet that criteria, and thousands and thousands around the country who have some relevant work experience that might suit them for HUD director.

During the campaign, Trump said that Carson could not be trusted, and he said it in breathtaking terms:

…I don’t want a person that’s got pathological disease. I don’t want it. I’m not saying he’s got it, he said it.

This isn’t something that I’m saying, like “Oh, he’s pathological liar.” I’m not saying it! He said he’s got pathological disease. He actually said pathological temper.

And then he defined it as disease. So he said he has pathological disease.

Now. If you’re pathological, there’s no cure for that, folks.

Okay, there’s no cure for that. And I did one of the shows today. And I don’t want to say what I said. But I’ll tell you anyway. I said that if you’re a child molester, a sick puppy, you’re a child molester, there’s no cure for that. There’s only one cure—we don’t want to talk about that cure. That’s the ultimate cure. Well, there’s two, there’s death, and the other thing.

Comparing your opponent to a child molester, saying that they’re pathologically diseased, and suggesting that only death or castration can cure them, those are not normal political attacks.

Trump went after Carson in the most personal way:

Then he vacillated between implying that Carson is an unstable thug who can’t be trusted in office because of violent things that he wrote about in his memoir, and declaring that his memoir is obvious bullshit that only dupes would believe.

He told people that they would be fools to believe Carson’s story of religious conversion.

Nonetheless, Carson eventually forgave Trump and endorsed him. In return, Trump floated his name for HUD in early November. But that was quickly shot down by Carson and his team:

Carson said through aides earlier in November that he would not be joining the Trump administration. “Dr. Carson feels he has no government experience, he’s never run a federal agency,” Carson’s close friend Armstrong Williams said. “The last thing he would want to do was take a position that could cripple the presidency.”

So, he had his spokesmen go out and say that not only was he not qualified to run HUD or any other agency of the government, but that he would possibly “cripple” Trump’s presidency if he attempted to do it.

It seems that Trump didn’t take no for an answer and somehow convinced Carson that he would be an asset rather than a catastrophic burden. But I don’t know that the Senate, which has the responsibility for confirming Carson, should believe Carson’s present assessment of his capabilities more than his initial one.

By most accounts, Ben Carson is a nice guy, and he obviously has a scientific enough mind to do brain surgery and aftercare for his patients. But science isn’t a strength of his in other areas. His ideas on the Big Bang Theory demonstrate this:

“I find the Big Bang really quite fascinating. I mean, here you have all these highfalutin scientists and they’re saying it was this gigantic explosion and everything came into perfect order. Now these are the same scientists that go around touting the second law of thermodynamics, which is entropy, which says that things move toward a state of disorganization. So now you’re gonna have this big explosion and everything becomes perfectly organized and when you ask them about it they say, ‘Well we can explain this, based on probability theory because if there’s enough big explosions, over a long period of time, billions and billions of years, one of them will be the perfect explosion.’ … So I say what you’re telling me is if I blow a hurricane through a junkyard enough times over billions and billions of years, eventually after one of those hurricanes there will be a 747 fully loaded and ready to fly. (Carson adds that the Big Bang is “even more ridiculous” because there is order to the universe.) Well, I mean, it’s even more ridiculous than that ’cause our solar system, not to mention the universe outside of that, is extraordinarily well organized, to the point where we can predict 70 years away when a comet is coming. Now that type of organization to just come out of an explosion? I mean, you want to talk about fairy tales, that is amazing.”

Despite the fact that biology is foundational to medical science, Ben Carson believes that the theory of evolution is encouraged by the devil. He also thinks the Egyptian pyramids were built to store grain, which is so loopy than even Trump abused him on Twitter about it.

It’s a curiosity that someone can simultaneously be a brilliant surgeon and totally detached from the standards and mores of the “highfalutin” scientific community, and that makes Ben Carson interesting. In most areas of his life, his grasp of cause and effect is seriously deficient. Perhaps he has enough self-awareness about this fact to know that he can’t be trusted to run a government agency anymore than he can be trusted to plot a probe’s trajectory to Mars.

It would be hard to run HUD so badly that it would cripple the Trump presidency, but maybe it’s possible. If the Senate confirms Carson, I guess we’ll find out.