When Anthony Thwaite's edition of Philip Larkin's Letters was published in 1992 and Motion's biography came out a year later, Larkin's enemies seized on the new disclosures with a frenzy hardly witnessed since the McCarthy era. What had hitherto been regarded only as potential inclinations hinted at in his poems - misogyny and zenophobia in particular - were now indisputable facts, and since then Larkin's reputation as a poet has been tarnished by...