If Aristotle is not a reliable guide to the purpose of tragedy, what was it for? In Aristophanes' Frogs, the debating tragedians make the claim explicitly that they should improve their audiences (1009–10) and that the poets have taught valuable subjects (1030–6). Taken for granted, however, is pleasure. When Euripides complains that Aeschylus's tragedies would have four chains of songs in a row while the actors were silent, Dionysus comments that he enjoyed this style (914–17). The Athenian audience could be loud and rude if not pleased: they yelled, hissed, and banged on the wooden seats, and sometimes performances simply stopped in the face of a hostile audience.
In traditional Greek culture, poetry was central to education, and its value was taken for granted. However, the sophists, who offered an alternative form of teaching, displayed their intellectual superiority by criticizing the poets, and by the late fifth century, intellectuals no longer assumed that poetry was valuable and instead began to theorize about it and to construct reasons why it was useful. Since tragedy obviously affected its audience, some critics, like Aristophanes, demanded that it be edifying. Tragedy could inspire emulation of heroic greatness or teach people how to argue. Plato, who did not think it could be morally beneficial, did not allow it in his ideal city.