In The Importance of Being Earnest, the characters’ foolishness is the core of the comedy. Often, we don’t know whether a character says something contradictory or random in a serious way, or if the character is just joking. This ambiguity in tone makes readers both slightly uncomfortable and prone to laughter. Wilde shows his characters’ folly in a number of ways: spinning something that is out of human control as if it were a simple matter of mundane choice, inverting aphorisms so that they mean the opposite of what common sense dictates, and simply juxtaposing random things so that they create an absurd situation.
In The Importance of Being Earnest, the crux of Wilde’s humor depends on inversion of common sense and juxtaposition of random elements.