The eighth chapter of the 39th book of the histories of Livy is considered an introduction to his narrative on the Bacchanalia. This chapter first points out the fact that the authorities dealt with the affair of the Bacchanalia before a military action very important. Therefore, you can regard it as a programmatic preface. Even according to Walsh, the events recounted by Livy are distributed in a recognizable dramatic form, and the eighth chapter can be seen as a prologue to the work, in which the author informs the audience on the subject of comedy and its antecedents.

This section also mentions the rise and spread of the Dionysian mysteries and the crimes related to the exercise of religion emerged in the investigation of the consul Postumius, which are described later.