LEON POLK SMITH was born in Chickasha, Oklahoma (U.S.A.) in 1909. Leon Polk Smith studied at Oklahoma State College and Columbia University, New York. His stylistically pure work immediately influenced the most advanced circles of geometrical research in the United States and served as the starting-point for other movements subsequently developed with success. His first works, made in 1945, revealed his mode of operation: determination of a figure, its obsolescence, determination of a new figure, which at the same time includes and surpasses the first figure. This procedure is carried out according to certain laws, also mathematical, the task of the artist remaining that of a continuous discovery of the laws of vision. From 1947 he posed with extreme clarity the problem of Mondrian: the conceptual range of his images, but also their limit, of which Mondrian himself, in his last years, was aware. The straight lines, the coordinates, the elementary colors are unquestionably a part of the problem, but they exclude curves, circles and derived morphologies. This poses the problem of their combination, organic unity that is expansion, tension, and reciprocal attraction. His contribution to the memorable "Responsive Eye" exhibition at the Museum of Modern Art, New York, in 1965, was important. In his work the logical opposition of vertical and horizontal is replaced by a more elastic relationship of positive and negative and by the analysis of the necessary ambiguities of perception, the complex relationship of the regular and the irregular: in this context the series called "Correspondences" is significant. In his more recent works he has made use of shaped canvases, as more suitable to express the effects of tension between positive and negative zones, and of only two colors constituting complementary parts of the same figure representing the total perceptive field. Subsequently, in the "Constellations" the colors were grouped together: the colored elements touch in a single point, which seems to generate the forces of attraction and repulsion of the masses. He has had numerous personal exhibitions in the United States and his work has been shown in many large thematic exhibitions. It was included, in 1977, in the "Paris-New York" exhibition which inaugurated the Center Pompidou in Paris, in the "Art in America After World War II" exhibition at the Guggenheim museum in New York in 1979 and, in the same year, in the "Mondrian and Neo-Plasticism in America" exhibition at Yale University. In 1983 he had a personal exhibition at the Nationalgalerie in Berlin. Since 1934 Leon Polk Smith has taught at American universities.