Earnestness, which implies seriousness or sincerity, is the great enemy of morality in The Importance of Being Earnest. Earnestness can take many forms, including boringness, solemnity, pomposity, complacency, smugness, self-righteousness, and sense of duty, all of which Wilde saw as hallmarks of the Victorian character. When characters in the play use the word serious, they tend to mean “trivial,” and vice versa. For example, Algernon thinks it “shallow” for people not to be “serious” about meals, and Gwendolen believes, “In matters of grave importance, style, not sincerity is the vital thing.”
For Wilde, the word earnest comprised two different but related ideas: the notion of false truth and the notion of false morality, or moralism. The moralism of Victorian society—its smugness and pomposity—impels Algernon and Jack to invent fictitious alter egos so as to be able to escape the strictures of propriety and decency. However, what one member of society considers decent or indecent doesn’t always reflect what decency really is. One of the play’s paradoxes is the impossibility of actually being either earnest (meaning “serious” or “sincere”) or moral while claiming to be so. The characters who embrace triviality and wickedness are the ones who may have the greatest chance of attaining seriousness and virtue.