Topic summary
Conceit

Extracted from the Wikipedia article Extended metaphor.
Metaphysical conceit
The metaphysical conceit is often imaginative, exploring specific parts of an experience. A frequently cited example is found in John Donne's "A Valediction: Forbidding Mourning", in which a couple faced with absence from each other is likened to the legs of a compass. In comparison with the earlier conceit, the metaphysical conceit has a startling, unusual quality: Robert H. Ray described it as a "lengthy, far-fetched, ingenious analogy". The analogy is developed throughout multiple lines, sometimes the entire poem. Poet and critic Samuel Johnson was not enamored with this conceit, critiquing its use of "dissimilar images" and the "discovery of occult resemblances in things apparently unlike". His judgment, that the conceit was a device in which "the most heterogeneous ideas are yoked by violence together", is often cited and held sway until the early twentieth century, when poets like T. S. Eliot re-evaluated the English poetry of the seventeenth century. Well-known poets employing this type of conceit include John Donne, Andrew Marvell, and George Herbert.