In 1902, when the late Paul Klee was 23 and a promising Swiss painter, he decided to start all over again. "I want to be as though newborn," he wrote in his journal, "knowing nothing about Europe...." Part of his new birth was to unlearn all the techniques he had acquired for making "acceptable" pictures.
Klee, wanting to paint like children, knew that children paint not to make beautiful pictures, but simply for the fun of picturing what they feel—art-for-my-sake. For grownups who have little childhood left in them, Klee's work, like children's, is something pretty hard to understand.
Last week an exhibition...