From The New Yorker:
Editing takes a variety of forms. It includes the discovery of talent…. It can be a matter of financial and emotional support in difficult times…. an editor ordinarily tries to facilitate a writer’s vision, to recommend changes… that best serve the work…. editorial work is relatively subtle, but there are famous instances of heroic assistance: Ezra Pound cutting T. S. Eliot’s “The Waste Land” in half when the poem was still called “He Do the Police in Different Voices”; Maxwell Perkins finding a structure in Thomas Wolfe’s “Look Homeward, Angel” and cutting it by sixty-five thousand words.