Emerson’s remark helps suggest the all-important difference: “It is not meters, but a meter-making argument that makes a poem.” In this kind of poem the poet establishes regularity only to depart from it expressively. When he does compose a metrically regular line it is not because the metrical scheme tells him to, but because something in the matter he is embodying impels him toward a momentary regularity. […]
The poet working in free verse has already chosen to eschew one of the the most basic expressive techniques in poetry.
Paul Fussell: Poetic Meter and Poetic Form
(from Chapter 3, Metrical Variations)
‘A lot of people high up in poetry circles look down on rhyme and metre and think it is old-fashioned,’ said Bernard Lamb, president of the QES and an academic at Imperial College London. ‘But what is the definition of poetry? I would say, if it doesn’t have rhyme or metre, then it is not poetry, it is just prose. You can have prose that is full of imagery, but it is still prose.’
Medieval theories of meter, in fact, frequently assume that the pleasure man takes in meter is a simulacrum of the pleasure he takes in the observation of the principle of order and recurrence in a universe which is itself will and order incarnate.
from: Poetic Meter and Poetic Form, Paul Fussell 1965
by simulacrum I guess he must mean an insubstantial form or semblance of something; or maybe the replacement of reality by its representation – or perhaps merely an image devoid of the substance contained in the original?
IMAGE CREDIT: sodahead.com
…since the would-be quantitative poet was obliged to remember constantly the arbitrarily assigned “quantities” of the English syllables he chose to use, quantitative composition was a laborious academic-theoretical business, like all such nonempirical enterprises more gratifying to the self-congratulating practitioner than to the perplexed reader.
P. Fussel, Poetic Meter and Poetic Form, Ch. 4: The Historical Dimension