The Chorus appears in this play as an interesting character in its own right, underscoring the conflict between the accepted value of obedience and the possibly higher value of friendship. The role of the chorus in a Greek tragedy is to uphold the moral standard. When Prometheus appears too rebellious or defiant, the Chorus clearly tells him that he would be wise to tone down his rhetoric. The Oceanids essentially uphold three positions. First, one must not rock the boat. The Greeks believed that a happy medium was always the ideal to strive for, so that the Chorus reprimands Prometheus for disrupting the harmony of the universe and the human/divine balance of power. Prometheus is too excessive and he should learn some moderation. Second, the Chorus teaches that one must remain pious and obedient. The Oceanids suggest that there is enough reason to fear Zeus to make one bow to him instead of defying his orders.
Finally, the Oceanids advise that one act prudently. Prudent action means not only that one should avoid angering a powerful and tyrannical Zeus, but also that one should not help those who cannot return the favor—this is prudence in its full form. So far all this is the normal role of the Chorus in a Greek tragedy. What makes this Chorus so interesting is the concluding deviation from all these moral teachings. Particularly, the Oceanids reject prudence and obedience as the main reasons for action and instead take up friendship. This is defiant because the action of staying with Prometheus contradicts divine orders. It is also imprudent since, the Chorus is helping a friend who cannot help back and because punishment here is not a possibility but a certainty. The Chorus's sudden reversal of the moral position it had been preaching is clearly significant. Friendship is a recurring theme throughout the play, often in accusations that Zeus does not trust his friends or hints that he doesn't really understand the concept. The Chorus, by deciding to honor friendship as the highest value, gives precedence to the view that friendship is a value superior to all others.