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
20th-century Western painting for that spiritual knowledge. Other major pioneers of early abstraction include Swedish painter Hilma af Klint, Russian painter Kazimir Malevich, and Swiss painter Paul Klee. Robert Delaunay was a French artist who is associated with Orphism, (reminiscent of a link between pure abstraction and cubism). His later works were more abstract, reminiscent of Paul Klee. His key contributions to abstract painting refer to his bold use of color, and a clear love of experimentation of both depth and tone. At the invitation of Kandinsky, Delaunay and his wife the artist Sonia Delaunay, joined The Blue Rider (Der Blaue Reiter), a