the kinship between El Greco and Cézanne, whose works he understood as the gateways to a new era of painting. Again, Kandinsky, who had seen Cézanne's painting at the 1907 retrospective at the Salon d'Automne, refers to Cézanne in his 1912 treatise On the Spiritual in Art, in whose work he found a "strong resonance of the abstract." recognized and found the spiritual part of his beliefs predetermined in him. El Lissitzky emphasized his importance for the Russian avant-garde around 1923, and Lenin suggested erecting monuments to the heroes of the world revolution in 1918; on the roll of honor were Courbet and Cézanne. Next to Matisse, Alberto Giacometti dealt most extensively with Cézanne's style of representation. Aristide Maillol worked on a Cézanne monument in 1909, but failed due to rejection by the city of Aix-en-Provence. Cézanne was also an important authority for artists of the newer generation. Jasper Johns described him as the most important role model alongside Duchamp and Leonardo da Vinci. Inspired by Cézanne, Albert Gleizes and Jean Metzinger wrote: Cézanne is one of the greatest of those who changed the course of art history ... From him we have learned that to alter the colouring of an object is to alter its structure. His work proves without doubt that painting is not—or not any longer—the art of imitating an object by lines and colours, but of giving plastic [solid, but alterable] form to our nature. (Du "Cubisme", 1912)Albert Gleizes, Jean Metzinger, Du "Cubisme", Edition Figuière, Paris, 1912 (First English edition: Cubism, T. Fisher Unwin, London, 1913) Along with the work of Vincent van Gogh and Paul Gauguin, the work of Cézanne, with its sense of immediacy and incompletion, critically influenced Matisse and others prior to Fauvism and Expressionism. Cézanne's explorations of geometric simplification and optical phenomena inspired Picasso, Braque, Metzinger, Gleizes, Gris and others to experiment with ever more complex views of the same subject and eventually to the fracturing of form. Cézanne thus sparked one of the most revolutionary areas of artistic enquiry of the 20th century, one which was to affect profoundly the development of modern art. Picasso referred to Cézanne as "the father of us all" and claimed him as "my one and only master!" Other painters such as Edgar Degas, Pierre-Auguste Renoir, Paul Gauguin, Kasimir Malevich, Georges Rouault, Paul Klee, and Henri Matisse acknowledged Cézanne's genius. Ernest Hemingway compared his writing to