Piet Mondrian (1872-1944) was a Dutch painter who believed in the spiritual in nature. His art was an expression of that spirituality. He believed that the trees, the verticals in nature, were the masculine principle, and the earth, the female. Together the union of the male and female constituted the beauty of creation. He started out painting vibrant trees and eventually wound up painting complete abstractions of vertical and horizontals with primary colors– very unlike his early landscape painting, but the underlying principles were the same.