Rhetorical Arguments

Last class, we discussed the three different areas/sectors of poetry: rhetoric, image, and diction. I came across this poem, which was interesting because unlike many of Szymborska's other poems, image does not play as prominent role--and rhetoric is much more important.

Certainty

"Thou art certain, then, our ship hath touch'd upon
the deserts of Bohemia?" "Aye, my lord." The quote's
from Shakespeare, who, I'm certain, wasn't someone else.
Some facts and dates, a portrait nearly done before
his death...Who needs more? Why expect to see
the proof, snatched up once by the Greater Sea,
then cast upon the world's Bohemian shore?

First of all, the syntax and diction of this poem are much less abrupt than some of the author's other poems. If read out loud, I don't know that the reader would necessarily know that it is poetry, not prose. And, the poem is only seven lines: it is like a snippet of a conversation that one might overhear. Next, the second half of the poem is strongly rhetorical--the speaker asks several questions that have strong argumentative undertones. While some of the diction is more descriptive--"snatched up" and "cast upon"--for example, the intention of the poem is to argue that Shakespeare was actually Shakespeare, not some other author. The intention is laid out very clearly, and the lack of inference needed on the part of the reader makes the poem atypical. Could this poem be made stronger with the addition of image and more "poetic" diction? Does it make an effective rhetorical argument? I think that the poem needs to be longer, since the reader is not given many details or analysis by the speaker of the poem.