From the earliest part of the century on, it's American poetry, not British, that's been considered the fresher and more engaging. Thurley, a game Englishman, says not so in this provocative, iconoclastic, common-sensical snipe. No student of American poetry will be unoffended--which is, if you think about it, rather nice. According to Thurley, 19th-century American diversity--""a provincial symptom. . . a desperate improvisatory ingenuity replacing real formal control""--gives way to a Twenties poetic, like Wallace Stevens', that is ""better"" but yet lacks the ""full, natural sense of personality"" that Yeats, Lawrence, and Larkin own by cultural birthright. The century continues dully. Muffled in the early Fifties under the ""neo-metaphysical"" Freudianisms of academics like Berryman, Lowell, and Roethke, important ""phenomenalist"" work, such as that of Rexroth and Patchen, is ignored. Olson's Black Mountain College aesthetics are a setback, a formalism based on quasi-science that's hardly more liberating than that of the New Critics. (Thurley's contradictions don't bother him; he's against ""objectism""--""man is a subject,"" he insists--while scoring the ConfessionaLs for their beans-spilling.) With Lawrence in mind, Thurley is looking for a sexy no-nonsense explosion--and Beat poetry gives it to him: Ginsberg, Corso, John Weiners, Philip Whalen: high intelligence, great risks, full commitment. This poetry makes up ""the American moment."" Thurley watches it go, too; sees more recent American poetry slink back to the safe and descriptive, even that written by the poets he garlands most. The free-swinging is refreshing; when he's not plain wrong or forgetful (where's W. C. Williams?), Thurley is right as a lock. Nettling, chauvinistic, skeptical, the book's a sharp workout for our sclerosing attitudes.