Classical rhetoric is divided into three categories based on rhetorical situation. These are referred to as the tria genera causarum or the three types of cases. The are:
- Deliberative: the rhetoric of legislative assemblies
- Forensic: the rhetoric of the courtroom
- Epideictic: ceremonial rhetoric
Because plays were performed at religious festivals, they are sometimes considered a genre of epideictic rhetoric, although for many ancient theorists, poetics and rhetoric were distinct literary genres. The assimilation of history and poetry into epideictic genres occurred to some degree in late antiquity but was really a typically medieval phenomenon, influenced by Averroes' confusion about the nature of classical drama and mimesis.
Within the play, there are no specific portrayals of rhetoric in its classical genres, but as characters deliberate about how best to persuade Philoctetes to join the Greek cause and such deliberations reflect on arguments about the future, one could characterize such debates as deliberative.
Odysseus tends to emphasize logical appeals and in his argumentative style is clever and manipulative. The Greeks, especially Odysseus, have a problem in their ethos, as they have previously mistreated Philoctetes. Neoptolemus is better positioned to persuade Philoctetes from both extrinsic ethos (his youth, his position as the son of Achilles) and from his intrinsic ethos as an honorable man. Eventually, the play is resolved by divine intervention, with Hercules using the authority of the gods to resolve the debates.