ABSTRACT
The rediscovery of consciousness was consolidated by the development of an experimental approach to mental imagery by A. Paivio and R. N. Shepard, among others. The notion that unconscious processes are important elements of mental life is very old. Inspired by Immanuel Kant’s distinction between noumena and phenomena, the unconscious was apparently a popular theme in nineteenth-century German philosophy, especially among the Romantic philosophers. One research tradition contributing to the modern interest in the psychological unconscious is the distinction commonly drawn between "automatic" and "strategic" cognitive processes. A. Schopenhauer, in The World as Will and Idea, argued that human thought and action was driven by unconscious, irrational instincts of conservation and sex. E. V. Hartmann fairly boxes the compass of the universe with the principle of unconscious thought. As cognitive psychology turned into cognitive neuropsychology, researchers began to see evidence of the psychological unconscious in the behavior of brain-damaged patients.
