Solitude
Though not explicitly mentioned as a motivator in the play, each major character's experience with solitude is what catalyzes their decisions and forms the central plot of The Comedy of Errors. At the beginning of the play, it is the division of the family (via the storm) that leads to the isolation of Antipholus of Syracuse, Dromio of Syracuse, and Egeon. This isolation is precisely what spurs the Syracusians to each search for their respective "other half" – Antipholus of Ephesus, Dromio of Ephesus, and though he does not know it, Egeon's wife Emilia. The play suggests through its focus on twinning and identity that self-knowledge (which Antipholus of Syracuse notably lacks) derives from one's relationships with others. Indeed, the triumph of the play is both the reunion of the family and the end of isolation for all characters involved.
Appearance
Like most early modern comedies, The Comedy of Errors uses appearance as its primary source of confusion and entertainment. Of course, the two sets of twins (with the same names nonetheless) bring the concept of appearances to the forefront of the play; they are constantly being mistaken for one another, and the confusion even drives Adriana to think her husband could be going mad. Early modern comedies frequently use disguise as a means of creating chaos, but The Comedy of Errors uses its twin characters in much the same way. By the end of the play, characters learn that appearances can not necessarily be trusted as a reflection of reality.
Family
Along with the theme of solitude comes its opposite: family and the reclamation of familial bonds. The beginning of the play introduces the audience to the Syracusian characters who, having been separated from half their family for two decades, decide to seek them out and end their suffering as a divided family unit. The desire to rebuild one's family serves as the primary motivation for most characters in the play (indeed, once Egeon realizes his second son and his servant may have disappeared, he travels to Ephesus himself despite the ban on Syracusians). In this play, family is portrayed as inextricable from one's identity and self-knowledge, as the twins come to know themselves through indirect interactions with one another.
Identity
Any early modern play featuring twins is bound to be interested in exploring identity and identity crises. The Comedy of Errors doubles down on this theme by portraying two sets of twins with identical names. This somewhat absurd structure helps highlight how identity – or lack thereof – affects each of the characters differently. Antipholus of Syracuse, for instance, is plagued by a sense of isolation and lack of self-knowledge; he does not necessarily know what will help him feel more complete, and strives to satisfy himself with outside sources. Identity is also the central point of confusion in the play, as the twins are constantly mistaken for one another. The play therefore suggests that identity is not fixed or absolute, but constantly in flux depending on one's circumstances.
Law
The beginning of the play features Egeon being told he will be executed if he cannot raise 1,000 marks by sundown. The law continues to linger in the background of the action, such as when Antipholus and Dromio of Ephesus are arrested for refusing to pay for the gold necklace. But law becomes most significant in the play due to its ineffectiveness: the Duke ultimately pardons Egeon and the Ephesians break free of their restraints in order to be reunited with their family. In this way, the play portrays the law as secondary to larger powers like family, love, and identity.
Gender
Gender is portrayed in a complex way in The Comedy of Errors. The character of Adriana is on the one hand strong and vocal, but on the other hand plagued by self-doubt when she suspects her husband's infidelity. Other female characters in the play are defined by their relationships (or lack thereof) with men: Luciana learning to interact with men, the courtesan taken advantage of by men, and the abbess (Emilia) swearing off men altogether once she thinks she has lost her husband. Thus, the play's portrayal of gender is intimately tied to identity, as it suggests that women's identity is explicitly linked to their connections to men – either by marriage, family, or labor.
Love and Marriage
Marriage is both the source of conflict and resolution in The Comedy of Errors. Of course, it leads to suffering once Egeon and Emilia are separated by the storm, suggesting that the bond between husband and wife is similar or at least as powerful as that between the twins who seek their siblings. The marriage between Adriana and Antipholus of Ephesus becomes a source of conflict once Adriana doubts her husband's faithfulness, though the couple is seen working through their problems with surprising compromise and mutuality. Luciana and Antiphlous of Syracuse represent another potential form of marriage through the match at the end of the play, as they are both somewhat uncertain of their identities and see marriage as an opportunity to rectify that doubt.
