A Poem provides an enclosed domain for investigation, challenging the critic to discover how it is constructed, how its formal structure is related to the complex effect it gives, how metrical means are related to poetic ends. Although kinship of form provides the critic with a positive basis for comparison in the treatment of different poems, the emphasis seems now to have shifted from the study of a poem’s shared and inherited qualities to the study of what is distinctive or typical of the age in which it is written; as a result, little attention is paid to the diversity of poetic forms—distinct, vital and active in themselves—working in the minds of many different poets independently, towards the same kind of poetic result.

Yet the fixed poetic forms and prescribed measures have a sort of philosophic beauty of their own. The poet must commit his feelings to their determination within some chosen form. The nature of his material sets a problem to be solved, and the solution is the poetic ordering of that material: he will, therefore, imagine each effect in relation to the technical means necessary for its accomplishment, by so distributing his rhymes, for example, that the emphasis derived from rhyme in one part is exactly neutralized by a similar concentration upon another.

The subject-matter of a poem exercises a remote control over the poet’s choice of words, and its form an immediate control, the metrical scheme tightening the interpretation of the grammar. Words have certain degrees of elevation in the scale of language.