Synchronicity: An Acausal Connecting Principle

Synchronicity: An Acausal Connecting Principle is an essay by Carl Gustav Jung, published in 1952 in German under the title Synchronizität als ein Prinzip akausaler Zusammenhänge. It appeared alongside a monograph by Wolfgang Pauli on the influence of archetypal ideas in Kepler's scientific theories, within a volume of studies from the C. G. Jung Institute, and is linked to a lecture Jung gave at the Eranos conferences in Ascona.

Jung describes synchronicity as a meaningful coincidence in time, a psychic factor independent of space and time. This concept both challenges and complements the physicist's classical view of causality, and forces a fresh consideration of chance, probability, coincidence and the singular events of our lives.

The work is organized into a preface, an exposition, an astrological experiment Jung conducted to test his theory, an appendix on the precursors of the idea, and a conclusion. Jung had been intrigued by coincidences from early in his career, and his long correspondence and friendship with the Nobel Prize-winning physicist Wolfgang Pauli inspired this mature statement of his thinking.