6.B The Conceit: Extended Metaphor at Full Stretch (FIG-1.AI)

A conceit takes two things that seem to have nothing in common and insists on a sustained, logical correspondence between them. The surprise is the point. Donne comparing two lovers to a drawing compass sounds absurd until you notice what the comparison lets him argue: one leg fixed, one leg roaming, yet joined at the head and drawing a perfect circle. The far-fetched vehicle is chosen because its specific mechanics match claims the poet wants to make about the relationship, not because it sounds pretty.

What keeps a conceit from collapsing into nonsense is that the poet works the comparison out, detail against detail, the way you'd work out a proof. Each part of the vehicle, the fixed foot, the leaning, the circle closing, has to correspond to something specific in the real subject: constancy, longing, reunion. That's also what separates a conceit from a metaphor that just runs long. A tired metaphor repeats itself for effect. A conceit keeps introducing new details because each one makes a distinct argumentative move, pushing the comparison further into new territory.

This is why conceits sit at the far edge of a poem's ambiguity and irony: the vehicle itself becomes an argument you can agree or disagree with, not just a mood. Swapping the vehicle changes the claim entirely. A compass makes love geometric, constructed, exact. A river makes it natural, one-directional, uncontrolled. Noticing which vehicle a poet picks, and which details get included, tells you what the poem is actually claiming about its subject, which is the same skill needed for reading paradox and loaded symbols elsewhere in the unit.