In 1944, when he was 68 years old, Carl Jung slipped on an icy road and broke his ankle; this led to a severe heart attack. While hovering between life and death, Jung experienced curious visions, in one of which he was hovering above the earth, out in space, then saw a kind of Hindu temple inside a meteor. "Night after night I floated in a state of purest bliss." He was convinced that if he recovered his doctor would have to die -- and in fact the doctor died as Jung started to recover. The result of these strange experiences was that Jung ceased to be concerned about whether his contemporaries regarded him as a mystic rather than a scientist, and he ceased to make a secret of his lifelong interest in the occult. In 1949 he wrote about the "acausal connecting principle" called synchronicity. In the following year he wrote his paper On Synchronicity, later expanded into a book. Unfortunately, Jung’s fundamental premise in both these works is basically nonsensical. Western science, he says, is based on the principle of causality. But modern physics is shaking this principle to its foundations; we now know that natural laws are merely statistical truths and that therefore we must allow for exceptions.
To explain "synchronistic" events, Jung was inclined to refer to a phrase of the French psychologist Pierre Janet, abaissement du niveau mental, "lowering of the mental threshold," by which Janet meant a certain lowering of the vital forces -- such as we experience when we are tired or discouraged and which is the precondition for neurosis. Jung believed that when the mental threshold is lowered "the tone of the unconscious is heightened, thereby creating a gradient for the unconscious to flow towards the conscious." the conscious then comes under the influence of what Jung calls the "archetypes" or "primordial images." These images belong to the "collective unconscious" and might be, for example, of a great mother, a hero-god, a devil-figure, or an image of incarnate wisdom. Jung thought that when the archetype is activated odd coincidences are likely to happen.
The medieval "magician" Albertus Magnus wrote:
A certain power to alter things indwells in the human soul and subordinates the other things to her, particularly when she is swept into a great excess of love of hate or the like. When therefore the [human soul] falls into a great excess of any passion, it can be proved by experiment that the [excess] binds things together [magically] and alters them in the way it wants. Whoever would learn the secret of doing and undoing these things must know that everyone can influence everything magically if [s/he] falls into a great excess.
That is to say, a psychological state can somehow affect the physical world. But Albertus’s "great excess" is clearly the opposite of Jung’s "lowering of the mental threshold." One is lowering of vitality, the other is an intensification of it.
Synchronicity is an explanatory principle; it explains "meaningful coincidences" such as a beetle flying into Jung’s room while a patient was describing a dream about a scarab. The scarab is an Egyptian symbol of rebirth, he noted. Therefore, the propitious moment of the flying beetle indicated that the transcendental meaning of both the scarab in the dream and the insect in the room was that the patient needed to be liberated from her excessive rationalism. His notion of synchronicity is that there is an acausal principle that links events having a similar meaning by their coincidence in time rather than sequentially. He claimed that there is a synchrony between the mind and the phenomenal world of perception.
Synchronicity provides access to the archetypes, which are located in the collective unconscious and are characterized by being universal mental predispositions not grounded in experience. Like Plato's Forms (eidos), the archetypes do not originate in the world of the senses, but exist independently of that world and are known directly by the mind. Unlike Plato, however, Jung believed that the archetypes arise spontaneously in the mind, especially in times of crisis. Just as there are meaningful coincidences, such as the beetle and the scarab dream, which open the door to transcendent truths, so too a crisis opens the door of the collective unconscious and lets out an archetype to reveal some deep truth hidden from ordinary consciousness.
Mythology, Jung claimed, bases its stories on the archetypes. Mythology is the reservoir of deep, hidden wondrous truths. Dreams and psychological crises, fevers and derangement, chance encounters resonating with "meaningful coincidences," all are gateways to the collective unconscious, which is ready to restore the individual psyche to health with its insights. Jung maintained that these metaphysical notions are scientifically grounded, but they are not empirically testable in any meaningful way.
All synchronistic phenomena can be grouped under three categories: