
Quote from "The Awe-Struck Witness" in TIME magazine (28 October 1974) http://www.time.com/time/magazine/article/0,9171,908926-1,00.html and in "On the Brink: The Artist and the Seas" by Eldon N. Van Liere in Poetics of the Elements in the Human Condition: The Sea (1985) ed. Anna-Teresa Tymieniecka
Variant translations:
The artist should not only paint what he sees before him, but also what he sees within him. If, however, he sees nothing within him, then he should also omit to paint that which he sees before him.
As quoted in German Romantic Painting (1994) by William Vaughan, p. 68
undated
Context: The artist should not only paint what he sees before him, but also what he sees in himself. If, however, he sees nothing within him, then he should also refrain from painting what he sees before him. Otherwise his pictures will be like those folding screens behind which one expects to find only the sick or the dead.