Does a good joke have to be explained? Most people would answer no. Does a good artwork have to be explained? Most people, depending on taste, would answer yes, no, or maybe. But what about humorous art? Does a joke that is an artwork have to be explained? Most people would not be able to answer this question. The most successful humourist in contemporary art is probably still David Shrigley. In every big gallery you can find his crude sculptures and badly drawn cartoons, and while his works sometimes make me laugh, I have never read a convincing explanation. Are...