Art will not only continue but will realise itself more and more. By the unification of architecture, sculpture and painting a new plastic reality wi… - Piet Mondrian

In 'De Nieuwe beelding in de Schilderkunst', Piet Mondriaan, 'De Stijl' No. 1, October 1917, p. 54

It may be noted that in Neo-Plastic art the crucial thing is the right angel, that is, the right-angle lines. And not whether the position of the lines is vertical or horizontal.. .So it is possible to make very beautiful things while placing the lines in a diagonal position.

The first thing to change in my painting was the color [c. 1908-09]. I forsook natural color for pure color. I had come to feel that the colors of nature cannot be reproduced on canvas. Instinctively I felt that painting had to find a new way to express the beauty of nature.