. . . if the artist is painting something that he knows and loves, as he knows it, because he loves it, whether it be the fair strawberry of Cima, or the clear sky of Francia, or the blazing incomprehensible mist of Turner, he is all right; but the moment he does anything as he thinks it ought to be, because he does not care about it, he is all wrong. He has only to ask himself whether he cares for anything except himself; so far as he does he will make a good picture; so far as he thinks of himself, a vile one.