I have a definite feeling for the West, the vast horizontality of the land, for instance... I have always been very impressed with the plastic qualities of American Indian art. The Indians have the true painter's approach in their capacity to get hold of appropriate images, and in their understanding of what constitutes painterly subject-matter. Their colour is essentially Western, their vision has the basic universality of all real art. Some people find references to American Indian art and calligraphy in parts of my pictures. That wasn't intentional; probably [it] was the result of early memories and enthusiasm.

As quoted in Twentieth-century American painting, Gail Levin, The Thyssen-Bornemisza collection. London, 1987, p. 267 - Art and Architecture (1944)