From Walt Whitman, "Song of Myself" section 3 in Leaves of Grass –

I have heard what the talkers were talking, the talk of the
beginning and the end,
But I do not talk of the beginning or the end.

There was never any more inception than there is now,
Nor any more youth or age than there is now,
And will never be any more perfection than there is now,
Nor any more heaven or hell than there is now.

Urge and urge and urge,
Always the procreant urge of the world.

Out of the dimness opposite equals advance, always substance and
increase, always sex,
Always a knit of identity, always distinction, always a breed of
life.
To elaborate is no avail, learn’d and unlearn’d feel that it is so.

Sure as the most certain sure, plumb in the uprights, well
entretied, braced in the beams,
Stout as a horse, affectionate, haughty, electrical,
I and this mystery here we stand.

Clear and sweet is my soul, and clear and sweet is all that is not
my soul.

Lack one lacks both, and the unseen is proved by the seen,
Till that becomes unseen and receives proof in its turn.

Showing the best and dividing it from the worst age vexes age,
Knowing the perfect fitness and equanimity of things, while they
discuss I am silent, and go bathe and admire myself.

This part of the poem always reads to me as a longing for a better rhetoric.  He hears the "talkers talking" and the specifics are left out.  The only thing that hangs for him is the sheer predictable subject headings of content. He longs for a type of talk that would communicate better these constants so that the real "mystery" of natural "urge" can be identified and explored.

A bit of Burkean identity/division talk in here. Most notable for the Burkeans is the observation that the world has all the perfection in it that the world started with.  Perfection is a constant amount for Walt.  Whitman attempts to avoid being "rotten with perfection," but at the end of the poem we find he can’t – that he still bathes before admiring his own body. If everything is as "clear and sweet" as his soul/not-soul, why bathe before admiring the body? A Great Burke Moment ™ for certain.

The poet has identified with "urge" (dividing him from . . .? The talkers?) but it still stands with him as a mystery.  Also interesting is the idea that proof extends from the category of things seen, which is a fluid category. Everything is proof of everything, it’s just in a different state at the moment of articulation. Eventually your "best evidence" won’t be believed anymore.

Perhaps we have a theory of rhetoric derived from watching the futility of argument – argument derived from principles that Walt doesn’t accept – leading him to a critique of the rhetorical foundations as a way of critiquing their arguments at the most foundational level.

This is a nice example of how poetry attempts to cut through the performative contradiction of this argument (the possible "My perspective is more fundamental and better than your’s"read which would put Walt in the same boat as those he’s criticizing). The contradictions are not eradicated but embraced, as we find Walt "silent" in the discussion yet "talking" to us about it, bathing and admiring his embodiment as "message," etc. 

He’s also mapping each and every age’s belief that they understand purity and origin as what they have in common – yet the only extant force for him is "urge" which is neither pure nor origin, it just "is." Using linear propositioned argument doesn’t quite convey this sensibility as well as the verse does.

Marshall McLuhan pointed out nicely in the Gutenberg Galaxy that in the 16th century free-verse or blank verse poetry became a technology of broadcasting, or mass media.  This Whitman verse serves as an example of the power and potential of this mode pretty nicely, don’t you think?