Drinking makes such fools of people, and people are such fools to begin with, that it's compounding a felony.

Benchley’s line is a characteristically dry, paradoxical joke: alcohol doesn’t merely reveal human foolishness, it amplifies it—turning an already error-prone species into something worse. By borrowing legal language (“compounding a felony,” i.e., making an offense more serious by adding another wrong), he frames drinking as an aggravating factor piled onto the baseline “crime” of human folly. The humor depends on exaggerated cynicism and mock-formal diction, a Benchley hallmark, and it also gestures toward early-20th-century American ambivalence about alcohol—where moral critique and convivial self-mockery often coexist.