Yes it is. But what was he doing with a Iris Murdoch novel in the first place? And Larkin's taste sometimes surprises you. Who would have thought he would be a fan of Stevie Smith? Or, to a certain extent at least, of Bob Dylan's lyrics?
Larkin loathed Iris Murdoch's novels. He and Monica Jones used to have a game where they defaced lines in Murdoch's The Flight From The Enchanter, rendering every line of the text obscene in some way. See page 319 of Andrew Motion's superb biography of Larkin.
I've never read any Murdoch; the fact that she was also a philosopher rather puts me off.