Philoctetes’ cave and possibility of teaching virtue

Plato's cave is one of the most striking and discussed metaphors not only in Plato's philosophy but in philosophy as a whole. However, the image of the cave as a place associated with the acquisition of new knowledge and the affirmation of one's own opinion appears in Sophocles' Philoctetes, that is, somewhat earlier than in Plato's Republic. The question of why Sophocles places the wounded archer Philoctetes on Lemnos in a cave with two mouths has been debated by scholars on numerous occasions, but the cave's design has most often been explained by the ease of movement of actors on stage or by poetic expediency. Both explanations are vulnerable to evidence, so the question of why Sophocles needed the cave’s two mouths has remained controversial for over a hundred years. The presence of the cave two mouths could indeed have been caused by both technical and poetic necessity, but the special structure of the cave could have allowed not only to effectively hide or reveal one or another hero from the audience. It's no coincidence that Sophocles' cave alludes to both the Odyssey, which features several significant caves, and the Iliad, which also features a diplomatic mission involving Odysseus. Referring to Homeric plot lines, Sophocles makes the cave not just a setting, but a metaphor explaining the complexities of Neoptolemus's moral choice, who, upon arriving on Lemnos, finds himself under the influence of two mentors - Odysseus and Philoctetes. Each has their own arsenal of pedagogical methods for instilling virtue in Neoptolemus, but the success of this indoctrination is called into question when, at the end of the tragedy, Heracles appears—a hero traditionally associated with the choice between virtue and vice.