"BIOGRAPHIES of writers, whether by themselves or others, are always superfluous and usually in bad taste," wrote W H Auden. Even more dismaying for his biographer, he declared: "I object in principle to biographies of artists, since I do not believe that knowledge of their private lives sheds any significant light upon their works." In his poem on Henry James, Auden noted that "there are many whose works/ Are in better taste than their lives", and the same might well be said of Auden, much of whose life was lived in a state of extraordinary disarray dominated by his addictions to fags and up...