Around 1941, Barzun took on a larger classroom, becoming the moderator of the CBS radio program “Invitation to Learning,” which aired on Sunday mornings and featured four or five intellectual lights discussing books. From commenting on books, it was, apparently, a short step to selling them. In 1951, Barzun, Trilling, and W. H. Auden started up the Readers’ Subscription Book Club, writing monthly appreciations of books that they thought the public would benefit from reading. The club lasted for eleven years, partly on the strength of the recommended books, which ranged from Kenneth Grahame’s “The Wind in the Willows” to Hannah Arendt’s “The Human Condition,” and partly on the strength of the editors’ reputations.