I need a word for the willful failure of reason

Kahneman's Thinking Fast and Slow is a brain dump of his research career and speculations about mind. The Wikipedia description isn't bad ...

... dichotomy between two modes of thought : System 1 is fast, instinctive and emotional; System 2 is slower, more deliberative, and more logical. The book delineates cognitive biases associated with each type of thinking, starting with Kahneman's own research on loss aversion. From framing choices to substitution, the book highlights several decades of academic research to suggest that people place too much confidence in human judgment...

The thing I like about Kahneman's framework is that it explains how smart people can do "dumb' things. System 1, for example, correlates well with IQ test results; people with a strong System 1 answer quickly and correctly. System 1 is snappy, fun, and easy. It's snap judgment and gut instinct.

System 2 though, System 2 is hard work. It takes time to train it. System 2 is graphics software without hardware acceleration; it's no fun.

Both Systems can give correct answers, but while Kahneman recognizes the power of System 1, his true love is the plodding logic of System 2. One of the more interesting chapters of the book is a rough heuristic for making predictions using System 1 instinct adjusted by Systems 2 logic.

For what it's worth, I think of myself as having a reasonable System 1, but a really good System 2.

Which brings me to the word I want; a word for people who have a strong System 1 but a weak System 2. I want a word for the Paul Ryans and GWBs of the world.

The word isn't "dumb" or "stupid". It's a word for a character flaw rather than a cognitive limitation, a word for someone who has the power to reason well but chooses not to practice it. It's a word for willful intellectual laziness.

Anyone have a good word? A knowledge of Latin might help...