Prostitution and infidelity
One of the main ideas expressed by the play is a critique of polite, conservative society by exposing the vice and malice that undergird much of the social discourse of the play. Infidelity is on major display, and so is its twin sister, deception. Most of the play has to do with people misusing trust to exploit their family. This occurs most noticeably in the constant references to prostitution and marital affairs. The play ends with the marriage of the trickster and the prostitute.
Vice and hedonism
Another way the play critiques polite society is the inclusion of hedonistic behaviors, which basically means that each character just does whatever they want without fear of repercussions. This changes for Penitent Brothel (whose very name signals this oxymoronic reversal) when he actually succeeds in getting what he wants, just to find that he has accidentally invited a demon. He quickly learns that despite what his hedonistic attitudes may have been, there is simply no getting around the fact that some things are right and some things are wrong.
Justice
Ultimately this leads to the final theme of the play, justice. Justice occurs when the forces of the society are in balance, so when one man steals from another man, either his property or his family, that could be said to represent imbalance. Justice occurs in the play, therefore, when the succubus attacks Penitent Brothel, whose penitent nature gives him enough valor to survive, but not without terror, and then also when the prostitute and the thief are married. This has archetypal significance, akin to the beast and the harlot, for instance.
