A half-generation ago, Joseph Heller’s book Catch-22 was all but required reading on every college campus.

The title of the book refers to a certain clause in military law, a clause having to do with grounding mentally unstable combat pilots.

At one point Yossarian, the book’s main character, talks with Doc Daneeka about grounding an obviously unstable pilot by the name of Orr. Yossarian learns how the rule works: The doctor can ground Orr if Orr claims he’s unstable and asks to be grounded. But if Orr asks to be grounded, then that’s proof he’s not unstable, and he has to fly more missions. Or, as Heller puts it:

"There was only one catch and that was Catch-22, which specified that a concern for one’s own safety in the face of dangers that were real and immediate was the process of a r…