In parapsychology, the key concept of a theory proposed by the Swiss psychiatrist Carl Jung to account for some paranormal and other puzzling phenomena, such as omens and prophesies.
According to Jung, there is no causal connection between, for example, two identical thoughts occurring to two individuals in different places at the same time or between a premonitory dream and the event which is seen to correspond with it (make it come true). Nor are such events due to pure chance. But there is a meaningful coincidence, or synchronicity, between two such more or less simultaneous occurrences in that they represent a manifestation of knowledge associated with archetypal processes in the collective unconscious.