From George Plimpton’s interview of Joseph Heller in “The Art of Fiction No. 51” (The Paris Review: Winter 1974, No. 60):
There’s an essay of T. S. Eliot’s in which he praises the disciplines of writing, claiming that if one is forced to write within a certain framework, the imagination is taxed to its utmost and will produce its richest ideas. Given total freedom, however, the chances are good that the work will sprawl.