Introduction- From the first, modernism felt it should embrace new developments in natural science. For obvious reasons, optical physics and colour theory were to be of lasting importance, from Kandinsky onwards. There was also some input by mathematics into cubism; Einstein's physics found parallels in futurist notions of the fourth dimension; and the curious biomorphs of Miró and Klee may be related to creatures seen under the biologist's microscope. But it was in the human sciences - more tenuous but richer in suggestion - that modern art found both its philosophical courage and a fountainhead of source material. The most important of these soft sciences - which appear even softer today than they did at the time were Freudian and Jungian psychology. The unconscious mind provided nothing less than a new world, a Prospero's island, in which artists could walk their imaginations and release their fantasies. The surrealist interest in dreams and automatism writing, drawing and painting without the mediation of thought cast an immensely long shadow over the whole culture of the twentieth century, while Jung's archetypes breathed new life into symbolism. The latter have persisted long after Jung the clinician has been consigned to the dustbin of history. They can be spotted, for example, in the later post-pop work of Peter Blake.