Proto-Cubism cubes": In light of the headway made by Cézanne, the multiple use of the word "cube" with reference to diverse works by diverse artists, and the other factors involved (political, social, cultural), it has been suggested that Cubism, with its proto-phase, would have emerged regardless of Picasso's intervention. The art historian and collector Douglas Cooper viewed Cubist painting to have been the beginning of a stylistic revolution which was inevitable. The American art scholar and MoMA curator William Rubin argued that Braque, with his commitment to a Cézannist syntax, would have created early Cubism had Picasso never existed. Pablo Picasso's
Georges Braque throughout Paris and then Europe. The two artists' productive collaboration continued and they worked closely together until the beginning of World War I in 1914, when Braque enlisted with the French Army. In May 1915, Braque received a severe head injury in battle at Carency and suffered temporary blindness. He was trepanned, and required a long period of recuperation. Braque resumed painting in late 1916. Working alone, he began to moderate the harsh abstraction of cubism. He developed a more personal style characterized by brilliant color, textured surfaces, and—after his relocation to the Normandy seacoast—the reappearance of the human figure.