Matisse's art, with its spectacular immediacy and its mysterious depths, poses confounding problems for analysis. When Hilary Spurling writes of The Piano Lesson that "the picture can not be confined to any single source or meaning," she might be writing of any of Matisse's works. Picasso's themes, with their collage of traditional signs and symbols, are far more susceptible to conventional iconographic analysis than anything in Matisse. Similarly, the cubism of Picasso and Braque, while rejecting traditional perspective, can nevertheless be studied as an inversion of traditional norms, using the same tools that one uses to study those norms. But the solutions that Matisse arrives at are always idiosyncratic and tend to be unrelated to any system of ideas. Intuition is his only system.