Writing plays is the counter-example that comes to mind first. Say "Beaumont" to an English major and he will respond "Fletcher", whether or not he has read the

Writing plays is the counter-example that comes to mind first. Say "Beaumont" to an English major and he will respond "Fletcher", whether or not he has read their plays. Shakespeare collaborated on at least one play. (Two Noble Kinsmen?) The Goncourt brothers wrote novels together until the one's decline and death--the linked piece mentions duos as more common. Why would writing with someone else necessarily leave the need unsatisfied?