It is easy to forget that the play The Double-Dealer, by William Congreve, is a comedy because of its sharp observation on the nature of evil. The overall theme of the The Double-Dealer is deception, which is hinted in the title itself. There are two forms of deception illustrated in Congreve's play: the deception conducted by sociopathic manipulators—namely Maskwell, Lady Touchwood, and Lady Plyant—and self-deception.

Maskwell and Lady Touchwood are the embodiment of dishonesty and selfishness. Maskwell, in particular, is a master manipulator, and like the biblical interpretation of the Devil, he charms and befriends his victims in order to lure them toward destruction. Lady Plyant is also a liar and cheats on her husband after she pretends to be prudish. These characters are similar to Jungian archetypes who represent the dark impulses of human nature.

Another theme in the play is the use of physical architecture to mirror psychological architecture. The hidden staircases, secret passages, back ways, and other labyrinthine architectural features are analogies for the antagonists' hidden agendas, secret dealings, and ulterior motives.