On different kinds of verse

Poetry is a form of verbal art that has been found in all languages and in all times. Most, perhaps all human societies put their language to the special use of composing poetry. What distinguishes all poetry from prose is that poetry is made up of lines (verses). Syllables, words, phrases, clauses and sentences are found in both prose and poetry, but only poetry has lines. It is the organization of the text into lines that defines poetry in all languages and literary traditions.

Poetry is, of course, not produced simply by segmenting a prose passage into arbitrary sequences of words or syllables and calling these lines. For a sequence of syllables or words to count as poetry it must satisfy a set of conditions which differ for different kinds of poetry. In metrical poetry, which is the subject of this book, lines must satisfy requirements on length and on the location in the line of marked syllables, and different conditions are met by different kinds of non-metrical poetry.

One type of non-metrical poetry is based not on line length, but on syntactic parallelism, where corresponding lines must be composed of syntactic constituents of the same kind. An example of such poetry is that of the Old Testament, of which an example in quoted in (1), where syntactic units of the same kind are labeled with the same capital letter.