Themes
Names and identity
The whole plot turns on a name. Gwendolen tells Jack in Act I that her ideal has always been to love someone called Ernest, because 'There is something in that name that inspires absolute confidence', and Cecily says almost the same words in Act II. Neither woman asks whether the man is earnest in character, and both men respond by booking a christening rather than telling the truth. The joke closes when the Army Lists show that Jack was christened Ernest John all along, so that he has, as he says, been 'speaking nothing but the truth' without knowing it.
Double lives and Bunburying
Both heroes lead double lives for convenience. Jack invents a wicked brother so that he can escape to town; Algernon invents an invalid friend so that he can escape to the country. Algernon gives the habit a name, Bunburying, and treats it almost as a philosophy: 'one must be serious about something, if one wants to have any amusement in life.' The play punishes neither of them. When the two fictions collide in the garden at Woolton, both inventions are killed off, Ernest by a severe chill in Paris and Bunbury by being 'quite exploded', yet the deceivers still win the women they deceived.
Marriage and money
Marriage in the play is a matter of lists and incomes. Lady Bracknell interviews Jack with notebook and pencil, approving his smoking, his ignorance and his investments until the handbag ends the interview. In Act III she has doubts about Cecily until she hears of a hundred and thirty thousand pounds in the Funds, after which the girl's profile shows 'distinct social possibilities'. Moments later she announces that she does not approve of mercenary marriages. Even Lane has a view: in married households, he observes, the champagne is rarely of a first-rate brand.
Class and manners
Upper-class manners in the play are a performance that barely covers the claws. Algernon complains that the lower orders do not set a good example, while Lane drinks the champagne and lies gravely about the cucumbers. Lady Bracknell is glad that education has no effect in England, since otherwise it might lead to 'acts of violence in Grosvenor Square'. The tea scene in Act II turns politeness into a weapon: Gwendolen says she has never seen a spade, and Cecily answers by loading her cup with sugar and serving her cake instead of the bread and butter she asked for.
Seriousness and triviality
The subtitle promises a trivial comedy for serious people, and the characters turn the two words inside out. Jack thinks Algernon is 'hardly serious enough'; Algernon later retorts that Jack has 'such an absolutely trivial nature' because he is serious about everything. People are grave about food and clothes and light about death: Algernon eats muffins calmly so that the butter will not get on his cuffs, while Jack's deep mourning for a brother who never existed is played for laughs. Gwendolen states the rule in Act III: 'style, not sincerity is the vital thing.'
Fiction and romance
The play mocks the novels and romances its characters live by. Cecily invents an entire engagement in her diary, with a ring, a bangle, a quarrel and letters she wrote herself, and calls the diary 'meant for publication'. Miss Prism explains that in fiction 'The good ended happily, and the bad unhappily', and her own lost three-volume novel turns out to be the cause of the whole plot, since she put the manuscript in the perambulator and the baby in the handbag. The ending, with its foundling, its long-lost brother and its recognised handbag, parodies exactly that kind of story.