He had never imagined so clearly the consequences of mailing a letter—the impossibility of retrieving it from the iron mouth of the box; the inevitability if its steady progress through the postal system; the passing from bag to bag and postman to postman until a lone man in a van pulls up to the door and pushes a small pile through the letterbox. It seemed suddenly horrible that one's words could not be taken back, one's thoughts allowed none of the remediation of speaking face to face.
Helen Simonson, Major Pettigrew's Last Stand
conversation, letters