Synthetic Cubism not only synthesized real materials with painted/constructed reality, but also synthesized earlier discoveries, permitting objects to seem tangible while forms and surfaces were shuffled in space as thin as gossamer. World War I ended the joint investigations of Picasso and Braque and dispersed the international community of artists who had gathered in Paris. Excepting Juan Gris and Ferdinand Leger, all of these artists, including the American artists, were on-lookers. Few grasped all of the issues and formal ideas with which Braque and Picasso experimented. Most seized upon an aspect of the style and wedded it to theories of their own, sometimes political, sometimes purely aesthetic. Those theories produced Futurism in I...