Synchronicity is a concept, first introduced by analytical psychologist Carl Jung, which holds that events are “meaningful coincidences” if they occur with no causal relationship yet seem to be meaningfully related.
During his career, Jung furnished several different definitions of the term, defining synchronicity as an “acausal connecting (togetherness) principle;” “meaningful coincidence;” “acausal parallelism;” and as a “meaningful coincidence of two or more events where something other than the probability of chance is involved.”
Jung’s belief was that, just as events may be connected by causality, they may also be connected by meaning. Events connected by meaning need not have an explanation in terms of causality, which does not generally contradict universal causation but in specific cases can lead to prematurely giving up causal explanation.
Jung tells the following story as an example of a synchronistic event in his book Synchronicity:
By way of example, I shall mention an incident from my own observation. A young woman I was treating had, at a critical moment, a dream in which she was given a golden scarab. While she was telling me this dream I sat with my back to the closed window. Suddenly I heard a noise behind me, like a gentle tapping. I turned round and saw a flying insect knocking against the window pane from outside. I opened the window and caught the creature in the air as it flew in. It was the nearest analogy to a golden scarab that one finds in our latitudes, a scarabaeid beetle, the common rose-chafer (Cetonia aurata), which contrary to its usual habits had evidently felt an urge to get into a dark room at this particular moment.
It was an extraordinarily difficult case to treat, and up to the time of the dream little or no progress had been made. I should explain that the main reason for this was my patient’s animus, which was steeped in Cartesian philosophy and clung so rigidly to its own idea of reality that the efforts of three doctors–I was the third–had not been able to weaken it. Evidently something quite irrational was needed which was beyond my powers to produce. The dream alone was enough to disturb ever so slightly the rationalistic attitude of my patient. But when the “scarab” came flying in through the window in actual fact, her natural being could burst through the armor of her animus possession and the process of transformation could at last begin to move.