(Originally posted at http://joelnoche.multiply.com/journal/item/73/Piet-Mondrian-Composition-with-Blue on September 22, 2011 10:04 AM)
The Wikipedia page on Piet Mondrian provides the following quote from him:
I believe it is possible that, through horizontal and vertical lines constructed with awareness, but not with calculation, led by high intuition, and brought to harmony and rhythm, these basic forms of beauty, supplemented if necessary by other direct lines or curves, can become a work of art, as strong as it is true.
The painting shown on the left is his Composition with Blue, 1926. (I got the image from this Philadelphia Museum of Art website.) Note that the painting has to be hung at a 45 degree angle so that the painted lines appear horizontal and vertical. This painting has an interesting history; it was confiscated from the Hanover Museum by the Nazi government in 1937 because it was considered degenerate art.