"I want to be an artist or nothing," wrote aspiring playwright Eugene O'Neill at the age of twenty-five. He pursued his goal relentlessly, and when he died forty years later he had written more than fifty plays, won the Nobel and several Pulitzer prizes, and earned his place as the first American dramatist of lasting, international stature. His work culminated with The Iceman Cometh and Long Day's Journey into Night, two of the most powerful portraits of despair ever created for the stage. Despite such accomplishments O'Neill's reputation has always been mixed. The playwright, wrote Mary McCarthy in Partisan Review, has not "the slightest ear for the word, the sentence, the speech." "[He] is no thinker," wrote director Eric Bentley in Kenyon Review. "Look at the fruits of his thinking; his comparatively thoughtless plays are better." As biographer Frederic Carpenter observed, however, O'Neill's primary goal was...