Caspar David Friedrich

The painter should paint not only what he has in front of him, but also what he sees inside himself.

Every true work of art must express a distinct feeling.

I have to stay alone in order to fully contemplate and feel nature.

If he sees nothing within, then he should stop painting what is in front of him.

Close your bodily eye, that you may see your picture first with the eye of the spirit. Then bring to light what you have seen in the darkness, that its effect may work back, from without to within.