Life and mind are continuously in conflict with each other. I want happiness, security. I won't reach that by considerations of my mind; on the contrary they will lead to a certain despair of the inner person. Not what he thinks engages the artist, but what he feels.
Art is not for the personal satisfaction of one or the other, but art wants to return all what's in life... Art wants to give back everything what's in our lives. The more comprehensive the artist stands in life the more powerful his work will speak, and therefore a work of art is a measure of the mental size of his creator.