Important Themes
Measure for Measure is technically a comedy, but rather than the death free-ending (only ambivalently "happy"), the most generically comic characteristic is the chaotic universe portrayed. This play is about society far more than romance, and justice is the thematic cornerstone. Measure for Measure asks the reader/viewer to think about the relationships between law and justice, between law and the lawgiver, between the letter and the spirit of the law, and between civil law and religious solace.
These issues are worked out against a backdrop of other concerns, such as the power of the aristocracy and the clergy. The character of the Duke, who gives up his aristocratic role to take on the religious mantle as a disguise is an excellent representation of both social positions of power. His actions raise questions about the proper scope of civil and religious authority; the Duke uses his disguise to the utmost as well, including performing religious rites as though he had the authority, which complicates the issue of religious power and role--only clergy could have had the sort of freedom of movement and automatic trust the Duke enjoyed, and these attributes alone allow the Duke the sort of control over the final outcome that he exercises.
The character of Angelo is equally fraught--he is also deceptive, but the disguise he hides behind is his reputation. Reputation, or the social persona that is constructed by the individual and the interpretation of society, is the main battle ground of this play: it is Angelo's most powerful weapon and greatest vulnerability.
Isabella is one of Shakespeare's most famous heroines, and she is a complex character who not only raises issues generally about the role and status of women, but about religion and law. One of the most commented upon moments of the play is the ending, where Isabella, at the last, does not act as she did throughout the play, but is acted upon. Her silence in the final scene generates space for widely varied interpretations of the Duke's proposal.
Images of the body and of disease, images that invoke or describe the senses, and images of duality or disguise (the "fantastical duke of dark corners" (IV.iii)) are some of the most common and most important in the play--not only figuratively, but literally as well. Language as a social medium is also a main concern, and this can be seen in the low comic plot in the character of Elbow as well as in the more deliberate utterances of Angelo and Isabella.