Seeing 20th-century art through the off-centre and, for all his popular successes, the ultimately secondary figure of Chagall throws up intriguing notions about the ancients versus the moderns. Chagall's old-age self-renewal was more apparent than real, owing a good deal to the post-Holocaust mood of the times.
The decline in the work of so many 20th-century masters in later life - not just Chagall but Matisse, Picasso, Braque, Munch, Vlam-inck, Rouault - inspires illicit thoughts. In art as in politics, insurrection has a cont-inuity problem. You can break up form and trash tradition with brilliant results - but then what? Picasso's dislocated nudes and Chagall's flying Jews delight and astonish, but pall in the end. Beethoven's late quartets and Titian's mythological poésie, painted in his seventies and eighties, do not.
