Van Gogh was right in saying that the method he had chosen could be compared to that of caricature. Caricature had always been "expressionist," for the caricaturist plays with the likeness of his victim, and distorts it to express just what he feels about his fellow man. As long as these distortions of nature sailed under the flag of humour nobody seemed to find them difficult to understand. Humourous art was a field in which everything was permitted, because people did not approach it with the prejudices they reserved for Art with a capital A. But the idea of a serious caricature, of an art which deliberately changed the appearance of things not to express a sense of superiority, but maybe love, or admiration, or fear, proved indeed a stumbling block as Van Gogh had predicted.

E.H. Gombrich
Another Quote

The Power Of Failure: We Get To Decide What It Means