Mondrian’s interest lay in the abstract quality of line but by 1914 he had all but eliminated the curved line from his work. By 1916 he had suppressed any sense of a subject. Still later he developed a new form of rigorous abstraction called Neo-Plasticism in which he limited himself to straight, horizontal and vertical lines and basic primary colours. Typically his compositions were not symmetrical but could scarcely be purer in their elements. He felt this art reflected a greater, universal truth beyond everyday appearance.