While reading Hayden Carruth's essay, "The Meaning of Robert Lowell", I came across this passage:
In essence, what is my theme? In general, what is my defect?One does not ask these questions once and then go on to something else; one asks them over and over, as one asks all unanswerable questions. A serious poet moves progressively toward his essential theme, though he can never reach it, by means of exclusions, peeling away, from poem to poem, the inessential, working down to bedrock; and he examines every word he writes for clues to his defect.
What Carruth describes here derives from the process of revision. Each poem is a challenge. The poet must discover the theme of it and remove everything extraneous. Maybe the poem has no discernible theme or maybe the superfluities are so entwined and essential to the poem they cannot be pared away without irrevocable damage; this is often the reason a poem fails. However, on those happy occasions where the theme—or themes in more complex works—holds, where it has an architectural strength, then it's possible to uncover a good poem. Much as Michelangelo saw the sculpture inherent in a piece of marble, the real work is to free it.
Of course, Carruth isn't limiting himself to the process of revision, but expands those concerns to encompass the whole of a poet's work, even the poet themselves. This is the level at which the questions become truly unanswerable. One can attempt to extrapolate a general flaw from the individual poems, but for the poet—particularly for the poet—it will largely stay hidden, just as one sees one's own personality flaws only with great difficulty. Even more elusive, though, is one's essential theme. Carruth suggests that to actually discover it is dangerous:
As I say, Lowell cannot discover the precise specifications of his theme, which is lucky for him. If he were to do so, he would be clapped into silence instantly.
This is a strange idea. One would think that knowing the "precise specifications" of one's theme would be freeing. However, I think what Carruth suggests here is that the struggle with one's own work, the process itself is what's important. To discover one's theme is to quit searching, to quit fighting to understand. As in life, the fight leads to excellence more than any achieved goal. In claiming that these questions are unanswerable, Carruth recognizes that, not only do the answers constantly change and slip away as one gets close, but that they don't matter that much anyway. The work alone matters.