In Euripides' Bacchae Dionysos visits Thebes in disguise to establish his mysteries there. And so, given normal Euripidean practice, it is almost certain that in the lost part of his final speech Dionysos actually prescribed the establishment of his mysteries in Thebes. In the same way the Homeric Hymn to Demeter tells how the goddess came in disguise to Eleusis and finally (vv. 476–82) established her mysteries there. After coming to Eleusis she performs certain actions in the house of king Celeus, for example the drinking of the κυκεών, which have long been recognized as corresponding to ritual undergone by the initiands in the Eleusinian mysteries. It is the main thesis of this paper that just as elements of the Homeric Hymn to Demeter seem to derive from a ἱερ⋯ς λ⋯γος of the Eleusinian mysteries, so certain elements of the Bacchae derive from a ἱερ⋯ς λ⋯γος of the mysteries of Dionysos, and that furthermore Euripides consciously alludes to the Dionysiac mysteries for a dramatic effect dependent on the religiosity of his audience, rather as Aeschylus alludes in the Oresteia, on the principle μαθο⋯σιν αὑδ⋯, to the mysteries of Eleusis.
This case will suffer from two drawbacks. Firstly there is the general scepticism about ritual patterns in drama arising as a reaction to the excesses of, for example, Murray and Cornford. This means that a far greater degree of probability seems to be required from suggestions of this kind than from the more traditional mode of speculation of, say, textual criticism. And secondly, it must be immediately and frankly admitted both that we do not know much about the mysteries of Dionysos and that most of what we do know is from the Hellenistic and Roman period. In the argument that follows recourse will sometimes be had to two assumptions. The first is to suppose a degree of continuity between the Dionysiac mysteries of the classical and later periods. This assumption is based firstly on the observable continuity of the mysteries: for example the antiquity of the Eleusinian ritual described by Plutarch, which will form an important part of my argument, is attested by Aristophanes and Plato. And it is based secondly on general considerations: conservatism is of the essence of those rituals in which a community such as a thiasos perpetuates itself by the transmission of a ritual treasured as originally taught by their god. The second assumption is to suppose, on the basis of numerous observable similarities, an essential similarity between the Dionysiac mysteries and the Eleusinian, about which we are well informed even for the classical period.