Oceanus, the Titan representing the ocean the Greeks believed circled the entire world, enters on a flying beast. Getting straight to the point, Oceanus expresses his friendship for Prometheus, offers his pity, and insists on going to Zeus immediately to bail Prometheus out. Meanwhile, he suggests, Prometheus should keep silent and stop provoking Zeus. Prometheus refuses this offer categorically, replying that Oceanus can achieve nothing by standing up for him. When Oceanus persists, Prometheus says that he would rather not have anyone suffer at the hands of Zeus on his behalf, since it already pains him that his brothers suffer Zeus's wrath. Oceanus asks whether Prometheus does not know that words are best for healing, but Prometheus responds that words only heal when spoken at the proper time. If Oceanus interferes, he will only bring Zeus's wrath down on them both. With this, Oceanus departs.
The Chorus again repeats that they shed tears for Prometheus, and that the entire world that was old before Zeus mourns for the suffering of Prometheus and his Titan brothers at the hands of the new tyrant. They say they have seen only one other Titan bound and tortured in this way: Atlas, who holds the world. Prometheus replies by summarizing all he has done for humanity. He taught human beings how to use numbers and language so they could remember what they have learned. He showed the paths of the stars and taught the use of ships. He also first harnessed animals so that they could do the work of human beings. Prometheus also introduced medicine and prophecy and divination through dreams, birds, sacrifice, and fire. Finally, he showed how to draw metals from the earth. Prometheus insists that he is responsible for all the arts of humanity.
The Chorus suggests that Prometheus helped humanity too much without thinking of himself, but he replies that his suffering is necessary, and he must bow to necessity like everyone else including Zeus. Here Prometheus comes close to revealing his secret prophecy, but then explains that he cannot reveal it to the Chorus because it will free him in the end only if he keeps it secret. The Chorus affirms their commitment to following the laws of Zeus and sings that Prometheus should not have helped creatures who cannot help him back.
Finally, they contrast the mournful songs they sing for him now with the songs they sang before to celebrate his marriage to their sister Hesione.
The exchange between Oceanus and Prometheus demonstrates further features of Zeus's servants, as well as Prometheus's character. Oceanus's sincerity in offering to help Prometheus does appear questionable. Prometheus, in any case, treats it with some sarcasm and is fairly terse in dismissing his would-be savior. Oceanus, meanwhile, does not get off his flying beast, and as he leaves even comments how eager his animal is to return home. Clearly Oceanus is drawn to offer help because of his bonds of kinship-Prometheus is a fellow Titan.At the same time, however, Oceanus is clearly wary of opposing Zeus in any way. He chides Prometheus, urging him to be less rebellious, and leaves as soon as his offer to help is refused. Oceanus may be a somewhat unwilling servant, but he is a servant nevertheless. His attitude reminds us once again of the political nature of divine interaction. Oceanus knows the extent of his powers, and though he finds Zeus extreme, he values his place in the current order.
Prometheus, meanwhile, is far less open with Oceanus than with the Chorus. He simply mentions that intervention will be useless, without revealing anything about the prophecy. Prometheus also invokes two reminders of Zeus's power-the imprisonment of Atlas and the defeat of Typho-to convince Oceanus that involving himself is not advisable. It seems likely that Prometheus does not fully trust the politically minded Oceanus and wants to get rid of him. Oceanus uses the metaphor of words as medicine for Prometheus's illness, hoping that this approach will appeal to the intelligence of the rebel. But Prometheus dismisses this, replying simply that medicine must be administered at the right time without revealing his knowledge of when the right time will be. Oceanus mentions that Prometheus should take him as his schoolmaster, but Prometheus sarcastically returns this comment a little later, suggesting that Oceanus does not need him as a schoolmaster. The two part as friends, but some suggestion has been made that Oceanus's offer to help was only a matter of business he felt was required by tact, and that Prometheus knows how to exercise the restraint he feels proper to each situation.
Prometheus's list of his contributions to humanity demonstrates several interesting features. Though mention is made to language and numbers, Prometheus mostly refers to material contributions. He lists these contributions in two sets with similar structures. Both lists begin with Prometheus mentioning that human beings need something. He begins the first list by speaking of the need for shelter and guidance, while he begins the second with a need for drugs to stave off illness. From there, Prometheus goes on to first person accounts of what he contributed.
In both lists Prometheus emphasizes one particular contribution to humanity by devoting more words to it than to the others. In the second list, he lingers over divination and prophecy, which fits with his character since he has the power to foretell the future. From the first list, however, Prometheus emphasizes the harnessing of animals to do human work, which seems at first an odd contribution to emphasize, especially considering how briefly writing and mathematics were invoked. This emphasis is important in reminding us of the importance of the sin for which Prometheus is punished. His crime is not simply stealing fire or giving it to mortals, but the fact that he took a power that belonged to the gods and gave it to mortals, thus disturbing the balance of power between human and divine. The harnessing of animals and the introduction of the yoke for human use underscore the seriousness of Prometheus's crime. Earlier, Hephaestus had spoken of the harness in which he binds Prometheus, and Prometheus's chains are referred to several times as "yoke" or "harness." Prometheus has given this power to imprison, previously held by Zeus alone, to mortals. He has thereby brought the divine closer to the mortal, disturbing the natural order of things.
The Chorus singers contrast their chants at Prometheus's wedding with their laments now. Zeus's ascent to power marks a boundary between happy and sad times. What separates these times is, in some sense, an ambiguous generational conflict. Zeus is a young god, unlike Prometheus, Oceanus, and the Oceanids. As a tyrant, however, he is the traditional stern father figure, as emphasized by references to him as the Father. Prometheus, despite belonging to the older generation, symbolizes progress in opposition to a static order imposed by Zeus. The suggestion appears to be that happiness requires a certain harmony between old and new. A casting aside of tradition is unfruitful and brings sadness.
Finally, the Chorus intentionally sets the stage for the next section of the play. Their comment about Prometheus's wedding to their sister, and the accompanying remark that she was of his "own race," seems oddly out of place. In a moment, however, Io will enter onto the stage to show the misery brought on by an unsuitable match. Though the Oceanids cannot know that her entrance is pending, Aeschylus uses their speech as a clever literary device to contrast Prometheus's marriage with the union we are about to hear about.