In evaluating a poem, Coleridge looks at it in holistic terms as a unity in which all the parts are joined together to form a satisfying whole. Every single line, every last word, should serve the purposes of the poem as a total piece of work.

Individual lines that are too perfect, too polished—and Coleridge has Pope's heroic couplets very much in mind here—can distract the reader's attention from the entire context of the poem, making the line a separate entity in its own right instead of a harmonizing part of a much bigger whole. A line should always serve the needs of the poem; it should never stand alone.

The very greatest poems for Coleridge are those that display internal consistency and unified perfection, reconciling opposite or discordant qualities to create a true aesthetic harmony as in the works of Milton and Shakespeare.