Infamous for cutting off his own ear and likely causing his own death by shooting himself in the stomach, Vincent van Gogh is the undisputed embodiment of the mad artist. Combine this image with his frenzied brushstrokes and vivid colours, and it is unsurprising that his artistic method is seen as impulsive and somewhat violent. So you may be surprised to learn that Van Gogh actually spent much time thinking carefully about his works, reconsidering his style and compositions. He did this especially through repetitions. You may well recognise his portrait of Joseph Roulin, the postman- but you might not be recognising quite what you think. There are six of…