Titan! to whose immortal eyes
The sufferings of mortality,
Seen in their sad reality
The poem opens with the use of a common literary device that has become confusing to some because it shares a name with a word that most people associate with something completely different. The speaker addresses the subject of his poem directly—though not by name—crying out “Titan!” Prometheus was one of the Titans of ancient myth. This form of literary address is known as “apostrophe” and the confusion is pretty self-explanatory. Typically, a poet will engage apostrophe in this manner to immediately establish a bond between the speaker and the subject of the address and that is especially true here. The Titan—Prometheus—was adopted by the group of Romantic poets with whom Byron is most closely associated as a kind of team mascot. He is their mythic figure of choice to represent the spirt of democratic rebellion against tyranny.
Thy Godlike crime was to be kind,
To render with thy precepts less
The sum of human wretchedness
This adoption as symbol of rebellion naturally raises the question: why? The answer is to be found here. The poem will, of course, make far more sense to anyone who is familiar with the mythic tale of Prometheus, especially since Byron is quite clearly writing in in an oblique manner which assumes this will be the case. For those unfamiliar, here’s the short version: Prometheus felt pity toward humans, so he stole fire from the gods of Olympus in order to give them the secret, but his theft was discovered and he sentenced to a cruel and painful punishment by Zeus. In other words, Prometheus rebelled against the authoritarian tyranny of the gods—Zeus, in particular—to help not himself, but the common man.
Still in thy patient energy,
In the endurance, and repulse
Of thine impenetrable Spirit,
Which Earth and Heaven could not convulse,
A mighty lesson we inherit
At this point, the speaker is making the transition from retelling the story of Prometheus to signifying as a symbol of rebellion for humanity to look to for guidance. The facts of the myth are that Prometheus was punished severely for his transgressions, but when looked at from a positive spin, that punishment becomes a demonstration of the Titan’s courage and rebellious strength. The lines go on to compare Prometheus to humans in a direct way that is open to interpretation in a way that led some to conclude the lesson to be inherited is that Prometheus is a Christlike figure—“Like thee, Man is in part divine.” The more reasonable interpretation, however, when considered within the contest of the complete myth is that instead of humans gaining a little divinity through Christ, Prometheus willfully made the choice to lose a little of his own divine status as a Titan by turning on the gods of Olympus in order to share the power of the gods with humans.