How is Ben Carson both so incredibly smart and so spectacularly stupid?

There are a lot of scientific prerequisites if you want to go to medical school — not just biology, but also chemistry and physics, even some math. By the time you get there, and certainly by the time you leave, you'll be long acquainted with the scientific method and the broad contours of scientific knowledge on those topics.

So imagine it's 1970 or so, and you're young Ben Carson, sitting in a biology class at Yale University. With your sharp mind and strong study habits, you don't have much problem understanding the material, grasping the copious evidence underlying the theory of evolution, all the fossils going back millions of years, how it all fits together in an endless process that affects everything from a towering redwood down to a microscopic virus. And yet, the whole thing sounds like an attack on the beliefs about the universe you were taught your whole life from your family and your church. How can you resolve this contradiction?

The resolution came somewhere along the way for Carson: Satan. Evolution is Satan's doing.

The fact that Carson believes this is a true puzzlement. Because Carson is an undeniably smart man. You don't get to be one of the world's most renowned neurosurgeons without the ability to understand complex systems, evaluate evidence, sift the plausible from the implausible, and integrate disparate pieces of data into a coherent whole. And yet he thinks that the theory of evolution is not just a great big hoax, but a hoax literally delivered to us from Hell.

Forgive me for my contemptuous tone, but that is what Carson actually believes. In a 2012 speech put up this week by Buzzfeed's Andrew Kaczynski, Carson says, "I personally believe that this theory that Darwin came up with was something that was encouraged by the adversary," and reveals that he plans to write a book explaining how the organs of the human body refute evolutionary theory. He also says the Big Bang is bunk, because the second law of thermodynamics says that entropy always increases, and there's too much order in the universe, what with things like galaxies and solar systems and planets. "Now that type of organization to just come out of an explosion? I mean, you want to talk about fairy tales, that is amazing." Someone should explain to him that order didn't arrive right out of the explosion, but over billions of years. You see, because of gravity...oh, never mind.

Carson's ideas about the Big Bang are quite similar to his beliefs about Islam, in that he picked up a snippet of information somewhere — there's a passage in the Koran that says this or that, there's a thing called entropy — and that snippet seemed to take hold of his rational faculties and beat them to a pulp.

To be clear, this isn't just about religious faith. There are millions upon millions of people in the world who believe fervently in a divine power, but who also acknowledge the truth of evolution. The Catholic Church, for instance, is quite clear that there's nothing incompatible between its theology and evolution. You can believe God set the process in motion or that God guides it down to the smallest detail; nothing about a belief in God prevents you from understanding and accepting what generations of scientists have discovered about the history of life on Earth.

So how do we explain this contradiction? All of us have some things we know a lot about and some things of which we're ignorant. Some of us are extraordinarily good at reading people and understanding social relations, but are helpless when it comes to math; others are just the opposite. Some of us pick up languages easily, others don't. Intelligence is complex and varied.

But what's so odd about Carson is that science is the very thing he was trained in, and the thing at which he excelled. Yet his religious beliefs are apparently so powerful that they completely overwhelm his ability to look objectively at any scientific area that might give some answers to what people once thought were purely metaphysical questions.

Training in science is also training in how to think — what sorts of questions can be answered in what sorts of ways, and how you know what you know and what you don't. That's why it's nearly as surprising to hear Carson offer as justification for his belief that no Muslim should be president, "Taqiyya is a component of Shia that allows, and even encourages you to lie to achieve your goals," as it is to hear him dismiss the Big Bang with a line about entropy. It isn't surprising that Ben Carson knows next to nothing about Islam; what is surprising is that, despite a career immersed in a very specialized field, he would think that he could listen to a couple of Glenn Beck rants and come to a deep understanding of a 1,400-year-old religion.

That's not to mention the fact that Carson's entire campaign for president is built on the rejection of knowledge and experience, in that he argues that all you need to succeed as president is common sense, even if you've never spent a day in government. That opinion, unfortunately, is widely held. As is, we should mention, belief in Satan — according to polls, a majority of Americans believe in the devil, so Carson is hardly alone.