What Caused the American Crack-Up?

F. Scott Fitzgerald wrote that "the test of a first-rate intelligence is the ability to hold two opposed ideas in the mind at the same time, and still retain the ability to function". His formula is justifiably famous, but it's worth noting that it comes from an autobiographical essay titled "The Crack-Up", which painfully detailed Fitzgerald's inability to pass his own test, and resulting descent into alcoholic dysfunction.