Joan Miró, Personages with Star, 1933, oil on canvas, 78” x 97”, Art Institute of Chicago, Photo by Xevi V via Flickr, Creative Commons Attribution-Non Commercial -Share Alike 2.0 Generic License.
Surrealist artists wanted to incorporate chance into their artwork because they thought it would be a powerful means of self-revelation and catharsis. They believed they could set free certain aspects of their subconscious this way.
Spanish artist Joan Miró, a Surrealist, sometimes would cut out images of machinery from a catalog and then scatter them on the surface of a canvas in order to incorporate an element of chance into his compositions. He then would change the pictures of the machinery into flat, biomorphic shapes and set them into a dream-like landscape. The result is the completely unique, sophisticated and immediately recognizable style for which he is well known today.