Who is the real subject of most love poems? Not the beloved. It is the hole. When I desire you, a part of me is gone: my want of you partakes of me. So reasons the lover at the edge of eros. The presence of want awakens in him nostalgia for wholeness. His thoughts turn toward questions of personal identity: he must recover and reincorporate what is gone if he is to be a complete person. […] Most people find something disturbingly lucid and true in Aristophanes’ image of lovers as people cut in half. All desire is for a part of oneself gone missing, or so it feels to the person in love.

Anne Carson, Eros the Bittersweet: An Essay.