Starry Night, van Gogh, 1889
"That is a little what Bernard and Gauguin feel, they do not ask the correct shape of a tree at all, but they insist absolutely that one can say if the shape is round or square - and my word, they are right, exasperated as they are by certain people's photographic and empty perfection.
Certainly they will not ask the correct tone of the mountains, but they will say: In the Name of God, the mountains were blue, were they? Then chuck on some blue and don't go telling me that it was a blue rather like this or that, it was blue, wasn't it? Good - make them blue and it's enough!
Gauguin is sometimes like a genius when he explains this, but as for the genius Gauguin has, he is very timid about showing it, and it is touching the way he likes to say something really useful to the young. How strange he is all the same."
van Gogh, 1889
Postscript: One has to like Emile Bernard, who got kicked out of art school in Paris for insubordination!