In trying to think how the horizontal, disseminating form of poetic lineation bisects or simply meets with the vertical, cohering force of the poem body, the uncanniness of poetic space presents and thus withholds itself as is fitting.
Perhaps it is not that the poem is born of the tension between poetry and prose, line-breaking and lineal resumption, but rather that this tension emanates from a more fundamental, cognitive, philosophical and embodied crossing, that between the horizontal and the vertical line.
The poem progresses, fitfully, across the impossible space it conjours at the end of its semiotically curtailed duration (ten syllables, abab rhyme, breath, graphic rhythm). At the end of each line it is confronted with an impassible territory, absolute alterior space, which however it must cross. First if it did not cross it there would be no poetry. Second if it does not cross it there is no space, the line just continues encroaching on and deferring the space, but never traversing it, resulting in prose. Which amounts to the same thing of course, the lack of poetry.
As it drops down to the next line, one is caught in an uncanny suspension. Your heart is in your throat, like a plane bucking in turbulence or a carriage plunging down the rails of a rollercoaster. You are moving simultaneously across and down, back and eventually up. A ferris wheel indeed rather than a rollercoaster.
1: you cross the space
2: you drop onto line 2
3: you return from the danger of the line end to the relative comfort of the line's (re)commencement
4: as you move down the lines the column of the poem rises up above you, while at the same time the tricks of enjambment regularly require you return to the lines above cataphorically to fully comprehend the semantics of the work
The poem is engaged, therefore, in a cross-hair of spatio-rhythmic effects. The horizontal progression, the fall, the retrogressive step and the rising up of the poem body.
Lineation is never a line as such, therefore, but a square. Made up of four sides it produces a quadratic aesthetic which is unavailable to prose.
It is not accidental that stanzas often resemble blocks because they are certainly always curtailed within the four barriers of being in a square.
Thus the tension in the poem is not simply, as Agamben suggests, between sound and sense. Rather there is an earlier tension within the peculiar semiotic of the poem.
1: bordering space of ending
2: suspension of meaning in the mode of dropping, translinear traversal
3: challenge of natal commencement, quasi-evental in fashion, of the begin again of each line
4: slow combination of lines moving down into a vertical entity that combines all of the other three effects into a promise of a curtailed and unified poem body which is both never fully realised and yet also impossible to ignore.
The poem will end but the verticality of the meaning of the work, its immanent transcendent potential, will never be realised except within the four-sided arena of the performance/reading of the poem itself.
One is caught in the quad, exits at all four sides, each of which, like that most uncanny of all computer games PacMan, lead one back into the square. The only way out of the poem is in, the only way into it is out.