Carl Jung

Synchronicity is the experience of two or more events which occur in a meaningful manner, but which are causally inexplicable to the person or persons experiencing them. The events would also have to suggest some underlying pattern in order to satisfy the definition of synchronicity as originally developed by Swiss psychologist Carl Jung.

Carl Jung coined the word to describe what he called "temporally coincident occurrences of acausal events." Jung variously described synchronicity as an "'acausal connecting principle'" (i.e. a pattern of connection that cannot be explained by direct causality), "meaningful coincidence" and "acausal parallelism". Jung introduced the concept in his 1952 paper "Synchronicity — An Acausal Connecting Principle", though he had been considering the concept for almost thirty years.^[1]

It differs from mere coincidence in that synchronicity implies not just a happenstance, but an underlying pattern or dynamic expressed through meaningful relationships or events.

It was a principle that Jung felt encompassed his concepts of archetypes and the collective unconscious ^[2], in that it was descriptive of a governing dynamic that underlay the whole of human experience and history — social, emotional, psychological, and spiritual.

Jung believed that many experiences perceived as coincidence were not merely due to chance but, instead, suggested the manifestation of parallel events or circumstances reflecting this governing dynamic. ^[3]

One of Jung's favourite quotes on synchronicity was from Through the Looking-Glass by Lewis Carroll, in which the White Queen says to Alice: "It's a poor sort of memory that only works backwards". ^[4]

Events that happen which appear at first to be coincidence but are later found to be causally related are termed Incoincident .

http://en.wikipedia.org/wiki/Synchronicity