<p>'I wrote my thesis because it seemed incredible that a nineteenth century cleric could believe that paintings had the power to civilise his community of London's poorest. Yet that is what he did believe and his ideas were exported round the world. I still don't know whether he was right...' Frances Borzello<br><br>What is the purpose of art? Aside from aesthetic considerations, does it have socio-political functions? Art critic Frances Borzell...