The thinkers who have set the stage for transpersonal studies are William James, Carl Jung, Roberto Assagioli and Abraham Maslow. More recent attention has brought to light transpersonal aspects of Jean Piaget's untranslated French works, and argued that Piaget's transpersonal experiences and theoretical interests were a major motivation for Piaget's psychological research. A review by Vich suggests that the earliest usage of the term "transpersonal" can be found in lecture notes which William James had prepared for a semester at Harvard University in 1905-6. The meaning then, different from today's usage, was in the context of James' radical empiricism, in which there exists an intimate relation between a perceiving subject and a perceived object, recognizing that all objects are dependent on being perceived by someone. Commentators also mention the psychedelic movement, the psychological study of religion, parapsychology, and the interest in Eastern spiritual systems and practices, as influences that shaped the early field of transpersonal psychology.