Here are a few translations of the lines in question. I couldn't find John Ciardi's translation, though I searched for it.
«S'i' credesse che mia risposta fosse
a persona che mai tornasse al mondo,
questa fiamma staria sanza pił scosse;
"If I believed that my reply were made To one who to the world would e'er return,
"If I thought my reply were meant for one
who ever could return into the world,
this flame would stir no more; and yet, since none-
If I could believe that my answer might be to a person
who should ever return unto the world, this flame would stand
without more quiverings; but inasmuch as, if I hear truth, never
from this depth did any living man return, without fear of infamy
I answer thee.
Henry F. Cary, 1888
"If I did think, my answer were to one,
Who ever could return unto the world,
This flame should rest unshaken. But since ne'er,
If true be told me, any from this depth
Has found his upward way, I answer thee,
"If I believed that my answer were made to one who would ever return to the world..."
"If I believed (S'io credesse) that my response was made (che mia risposta fosse
) to a person who might (A persona che mai)
James Finn Cotter:
If I thought that my answer was to someone
Who might one day return up to the world,
This flame would never cease its flickering.
Peter, going by Eliot's habits of mind (ref. Southam), the epigraph may have provided him with a clue, the all-important starting point, for conceiving this dramatic monologue as a disguised mode of confession [a la Montefeltro in Inferno] -- putting on the persona of a middle aged man. Apart from what "persona" denotes in the epigraph, it could easily suggest to Eliot the technique of "persona" as a masque for a character other than the poet himself.
Thanks & regards,
--- On Mon, 2/1/10, Peter Montgomery <[log in to unmask]> wrote: