Since the Richter quote seemed to bring some interesting questions (thanks Theo and Hans! I knew I could count on you!), here is some more fuel...
"pure painting is inanity, and a line is interesting only if it arouses interesting associations"
"The Photo Pictures [a series of photo-realistic paintings by Richter - Vv]: taking what is there, because one's own epxeriences only make things worse."
"Using chance is like painting Nature - but which chance event, out of all the countless possibilities?"
and finally, an apparently trivial one that I like a lot. Concerning an exhibition:
"The one thing that frightens me is that I might paint just as badly."