The strange and confounding and irresistible art of the modern era has several facets. That is one reason it continues to stir us. And it has never been as tidy or as ostensibly rational as traditional art. It has never settled for the obvious: Behold nature, the human pageant; re-state pictorially. After Cézanne, that notion soon became quaint. One forceful and purist strain of modernism has always insisted on the artwork’s autonomy, on a resolve to cre-ate objects that had little or nothing to do with the visible world. It gloried in the artist’s right to center on her/his inner landscape — the private ponderings, the private demons — or, in the fact, on art itself.