Euripides was writing during the beginning of the Dionysian invasion from the Near East, and so his play signals Dionysus's still incomplete integration into Greek religious and social life. Once Dionysus had been established as a legitimate god in the Greek pantheon, he became associated with civic forms such as theater, wine festivals, democracy and general revelry. But for Euripides, the relation between Dionysus and the established social order was still being contested. His play attempts to answer the question of whether there can be a space for the irrational within a well-structured and ordered space, either interior or exterior. The Bacchae depicts a struggle to the death between the twin forces of control (restraint) and freedom (release), and permits Dionysus to provide an answer to this question. The god's implicit message is that not only is there space within society for the irrational, but that such a space must be allowed for that society to exist and thrive. By denying or opposing the irrational, as Pentheus did, the person who opposes it, or the society that denies it, will be torn apart. The story of Pentheus and Thebes demonstrates the necessity of self-control, moderation, and wisdom in avoiding the twin extremes of the tyranny of order and the murderous frenzy of collective passion.
As the last work of his life, Euripides chose to write a play that discussed, among other themes, the origin and nature of his own art. The Bacchae deals with the different relationships of theater to various aspects of society, including its relationship to art itself. First, Euripides asserts the centrality of theater to Dionysian ritual. The rites alluded to in the play were replete with masked dancers, choral performances and processions of citizens in costumes. Dionysus, the god of the mask, offers his worshippers the freedom to be someone other than themselves, and in doing so, the chance to achieve a religious ecstasy through theater itself. Second, Euripides comments upon the relation of the individual self to the theater as spectacle and performance. In the beginning of the play, Pentheus is an external spectator and onlooker, gazing upon the bacchic rites with a removed, disapproving gaze. But when offered the chance by Dionysus, he moves from the margins to center stage of the drama himself. But Pentheus cannot navigate the dangers of the move, and loses control, losing himself to the role he wishes to play. He emasculates himself, loses his original identity as the rational sovereign, and exposes himself to the drama and its consequences—in his case, death. Third, Euripides wants to comment upon the play as an art form. He masterfully both draws the audience's attention to the artifice of the play, to its conventions and techniques, while at the same time asserting the seductive power of that very artifice, both over the characters in the play and over the audience itself.
One of the principal moral messages of the play extols the importance of maintaining fundamental balances in one's social and natural life, and Euripides demonstrates this principle in the structure and content of the The Bacchae. The play is sprinkled throughout with oppositions, doubles and pairings that can be organized into three categories. First, Euripides establishes a number of pairings between and even within characters: Dionysus takes two forms on stage, Pentheus serves as his double, and they switch roles in the course of the play. Cadmus and Tiresias are a pair, and the bacchic chorus and the mad women of Thebes provide a contrasting set. Second, there are formal dualities, including the chorus versus the main action of the drama, and the events recounted versus the events enacted. Third, thematic dualities feature strongly. The wild mountain is contrasted with the walled city, and the mortal denies—albeit futilely—the divine. Men face off against women, and the irrational does battle with the rational.