The House of the Prophet is Louis Auchincloss's searching novel of Felix Leitner, one of the most influential men of his time. Political philosopher, columnist, adviser to American presidents, Leitner will doubtless bring to many readers' minds the late Walter Lippmann, portrayed in the fine biography by Ronald Steel. Indeed, in his new introduction, Auchincloss makes plain that "the idea of writing a novel inspired by, though by no means based upon, the life of Walter Lippmann was unlike any fictional idea that I have had before or since." He candidly adds, "I was always perfectly aware the...