In December 2009 Banksy painted over a piece King Robbo had left on a Camden canal wall in 1985. Days later Robbo waded out and painted it back. That went on for two years — and it kept reminding me of an older quarrel, conducted more slowly and with better manners, between Matisse and Picasso.Continue reading “Two Ways of Growing Old — Matisse, Picasso and What a Rival Is For”