Julian Barnes is a long-time star of the London literati: a Francophile, and a slightly austere, wry and elegant Booker  Prize-winning novelist. He has also written extensively on the visual arts, almost exclusively on French nineteenth-century painting, with a few addenda on particularly strong, highly emotional – even at times ferocious in their use of paint – British artists: Lucian Freud and Howard Hodgkin. In this fascinating collection of these pieces, the surprising joker in the pack is the Swedish-American artist Claes Oldenburg. There is also, in an analysis of “Sensation”, the sensational 1997 exhibition at the Royal Academy, a meditation on what makes art. But, oh dear, the generalisations: “Art changes over time; what is art changes too.&rdqu