Henri Rousseau is at once one of the most popular and one of the most enigmatic artists of the modern era. 'Interpreting' his work presented no less of a problem for his contemporaries than it does for us today. Different accounts of his life and art make him out to be either the starting point for modernism on the one hand or a naive, 'primitive' artist, cut off from the developments around him, on the other. What was it about his paintings that...