In this big moonlit landscape by the painter N. N., that deservedly celebrated technician, one sees more than one would wish, or that can actually be seen by moonlight. But what the perceptive, sensitive soul looks for in every painting, and rightly expects to find, is missing.... If that painter could find it in himself to paint fewer, but more deeply-felt, pictures instead of so many clever ones, his contemporaries and posterity would be more grateful to him.

from his writings Thoughts on Art, Caspar David Friedrich; as quoted in Letters of the great artists – from Blake to Pollock, Richard Friedenthal, Thames and Hudson, London, 1963, p. 33