That this is a play about identity is heralded by the presence of two sets of identical twins who have been separated since they were babies. In Ephesus, each twin is constantly mistaken for his brother, leading him to question who he is. Antipholus S., on one hand, feels that he lost part of his identity when he was separated from his mother and brother, and arrives in Ephesus hoping to complete himself by finding them once more. Antipholus E., on the other hand, believes he knows exactly who he is: a well-established merchant of Ephesus, with a wife, a comfortable home, and a solid reputation as a businessman. Both Antipholuses find their assumptions about their identity shaken up. Antipholus S. is soon questioning his sanity and assuming that witches have put a spell on him. Antipholus E. loses all the 'props' that make up his self-identity in the confusion of events - wife, home, gold chain, and reputation.
Egeon, like Antipholus S., is also looking to complete his identity by finding his lost family.
Adriana, meanwhile, is a complex mix. She fiercely asserts her independence and power within her marriage, but at the same time she has so utterly sunk her identity into her role as wife that she believes that she and her husband are one indivisible whole. Because she thinks that the absence of one partner irreparably takes something away from the other, she over-reacts when Antipholus E. is absent from home. When, at the end of the play, the Abbess rebukes her for driving Antipholus E. mad with her jealous fits, she takes the message to heart and it is implied that she will change her behavior within the marriage.
Luciana's sense of identity within marriage contrasts with Adriana's. She believes that men are naturally lords over their wives, and wants to learn to obey before she learns to love. But she pairs up with Antipholus S., who spontaneously offers to take a submissive role in the relationship: he wants her to teach him how to think and speak, transform him, and create him anew. If she marries him, it seems that she will not merely obey and submit to him.
At the end of the play, the characters have their identities restored to them, thanks to the Abbess, who has the largest overview of the truth.
Debt is a theme that arises in almost every scene of the play. It appears in two forms: material debt (money and goods) and social or marital obligations. The play opens with the shocking incident of Egeon's incurring a massive debt of a thousand marks merely for being in the wrong place. If he cannot raise the money, he will pay with his life. The incident highlights the inhumanity of debt and the law that supports its demands. The law itself was created as a result of a perceived debt incurred by the city of Syracuse to the city of Ephesus. This came about when the city of Syracuse began to force Ephesian merchants to pay a ransom or forfeit their lives. Thus Syracuse created a harsh law for which Ephesus is paying it back.
The sense created by the Syracuse-Ephesus story and the entire theme of debt is that of a cruelly binding chain of cause and effect that ties the characters up in fear, deception, distress and jealousy, and banishes love, forgiveness, and friendship.
Antipholus E. has, in the view of his wife, neglected his marital obligations to her, thereby incurring an emotional debt. He tries to pay her off with a concocted story that he has been overseeing the making of her gold chain, so the gold chain, in a sense, becomes his manner of paying his debt. Then she unwittingly locks him out of his house, and to spite her and 'pay' her back, he decides to give the chain to the Courtesan instead - his way of denying that he owes anything to a wife he considers disloyal. The Courtesan in turn gives Antipholus E. a ring in exchange for the expected chain - but never receives the chain, and so is uncomfortably conscious of his outstanding debt to her. When Angelo is not paid by Antipholus E. for the chain (Antipholus E. did not receive it), he has the latter arrested in spite of the fact that they have been friends and business associates. The sense is, once again, that monetary values have gained an inhumane ascendancy over such values as friendship and love.
In the final scene, all outstanding debts are paid except, significantly, Egeon's ransom. The Duke, in his mercy, waives this debt, and thereby elevates the humane values of love and forgiveness above monetary values.
Love and marriage
This theme is explored in the relationship between Adriana and her husband, Antipholus E., and in the debate on marriage between Adriana and Luciana.
Adriana's marriage is not happy, though she undoubtedly loves her husband even when she believes him (wrongly) to be unfaithful. Part of the reason for her unhappiness seems to be that her love for her husband is so possessive (see also the theme of Identity) that she feels she is torn apart by his absences. Fiercely jealous of her husband's friendship with the Courtesan, she nags him about it incessantly and rebukes him for neglecting her. She feels that she has lost her attractiveness to him. Adriana's accusation of neglect may have some substance, as Antipholus E. spends a good deal of time with the Courtesan and, when he wrongly assumes Adriana is disloyal, spitefully decides to give to the Courtesan the chain intended for his wife.
In the debate between Adriana and Luciana, Adriana comes over as the archetypal 'shrewish' wife. She believes that wives should have power over their husbands and as much freedom as them. Her attitude to her husband is one of impatience and anger. Luciana believes that men are naturally created lords over their wives, that men must have more freedom because their business takes them out and about, and that Adriana should be more patient and gentle with her husband.
Both women seem to modify their stance in the course of the play and lean towards the other's position. Antipholus S. wants Luciana to teach him how to think and speak, and to create him anew, suggesting that she will not be a subservient wife - and she backs up her sister for upbraiding Antipholus E. for his neglect. Adriana seems to become milder. She unquestioningly supports her husband when she is asked for money to buy him out of jail. She also takes to heart the Abbess's rebuke for her "jealous fits." However, the Abbess is far from being the voice of reason, or the voice of Shakespeare, on this matter. She fatally undermines her case by doing a U-turn in her diagnosis of Antipholus E.'s supposed madness. First, she says Adriana has been too soft on her husband, then, when it is obvious that she has stood her ground, she changes the diagnosis, saying she has been too tough. Another factor that undermines the Abbess's authority in this case is that Antipholus E. is not mad; his erratic behavior has been caused by the confusion created by the presence in Ephesus of his twin.
The play lacks a single example of a happy marriage. That of Egeon and Emilia (the Abbess) was curtailed by the shipwreck, and they have been separated since then. And Luciana says she has not married because she only sees troubled marriages around her. It is unclear to what extent the married couples are fully reconciled at the end, and much room is left for interpretation by the theater director or the reader.
The theme of gender overlaps with the theme of love and marriage. Critical debate of this issue centers around Adriana and Luciana, in terms of their respective attitudes to marriage and men. The Abbess, Emilia is discussed both in terms of the restricted possibilities open to a woman in her situation (entering a convent) and in terms of her redemptive role at the play's end, which some critics see as embodying the female principle. She explains the confusion that has occurred and reunites her own divided family.