Much has been written about Auden's various ""voices,"" as if he were a ventriloquist act, though everyone agrees that the Audenesque tone or touch is unmistakable. ""Who could not recognize anything of his even if submitted anonymously?"" asked Robert Mazzocco recently. Nevertheless, he went on, ""between Auden's sense and his sensibility, between what he says and how he says it, lies a great gull."" Or, to be exact, three different periods of changing temperaments, masks, idea-mongering. In the Thirties, Auden was the dazzling interpreter of guilt, decay, apocalyptic camp; in the Forties, the pivotal years which Professor Nelson rather uninfectiously covers, he became Kierkegaardian and other-worldly; while the persona of the last two decades has been that of a ""lunatic clergyman"" (Isherwood's phrase) turning benevolent and commonsensical. Nelson believes that The Sea and the Mirror, For the Time Being, and The Age of Anxiety were ""poems Auden had to write rather than poems he wanted to write. They are works of transition, attempts to understand the incredible gap between a Hitler and a Williams."" The Williams referred to is Charles Williams whose exemplary ""life style"" and ""doctrine of substitution"" (Auden: ""Choosing to bear another's burden involves at the same time permitting another to carry one's own"") led, along with the Kierkegaard readings, to the poet's reconversion, as well as his break with Marxist historicism. A profound disruption and solidification suggests itself here, perhaps the key to Auden's towering and enigmatic career, but Nelson's lengthy textual explications and repetitive generalizations cio not take us very far, even if Auden himself remains limitlessly interesting.