The pure, frank sentiments we hold in our hearts are the only truthful sources of art. A painting which does not take its inspiration from the heart is nothing more than futile juggling. All authentic art is conceived at a sacred moment and nourished in a blessed hour; an inner impulse creates it, often without the artist being aware of it.

As quoted in "Culture: Caspar D. Friedrich and the Wasteland" by Gjermund E. Jansen in Bits of News (3 March 2005)