C.G. Jung (1875-1961), the noted Swiss psychotherapist, did not write at length about synchronicity until 1952 when he published an essay called, "Synchronicity, An Acausal Connecting Principle" which appeared together with an essay on archetypes in Kepler by Wolfgang Pauli whom we have already met in connection with quantum theory. Jung had been long aware of events in his own life and those of his patients that seem to defy the normal laws of causality. For example, one of his patients whose treatment had resisted progress because of her excessively rationalistic cast of mind, had a dream in which she received a golden scarab, an insect that plays an important role in Egyptian mythology. Later, when she was telling Jung the dream, he heard a gentle tapping at the window, and when he opened it, in flew a scarabaeid type beetle which was Switzerland's equivalent to the golden scarab, and he caught it in his hand and handed it to her and said, "Here is your scarab." This uncanny event had the effect of breaking through the rationalistic shell that she had built around herself.

In another case, a woman whose husband Jung was treating told him that when both her mother and grandmother had died birds had come and sat outside the house. Her husband developed some physical symptoms, and Jung sent him to a heart specialist who could find nothing wrong with him. After he left the doctor's office he collapsed dying in the street, and was carried home. His wife was already upset, for a large flock of birds had landed about the house after he had gone off to see the doctor.

These kind of events, that could be multiplied over and over again, led Jung to what he called synchronicity, or meaningful coincidence. There seemed no way to explain them through the normal action of cause and effect, and yet it seemed wrong to write them off as pure chance. Therefore Jung, with reluctance because of the difficulty of the matter, set out to try to make some sense of what could be going on. He reasoned that if these events were not causally connected, perhaps they were the manifestations of some acausal connecting principle. He was encouraged along these lines because it seemed that modern physics, in developing quantum theory, had broken with causality, and "shattered the absolute validity of natural law and made it relative.. The philosophical principle that underlies our conception of natural law is causality. But if the connection between cause and effect turns out to be only statistically valid and only relatively true, then the causal principle is only of relative use for explaining natural processes and therefore presupposes the existence of one or more other factors which would be necessary for an explanation. This is as much as to say that the connection of events may in certain circumstances be other than causal, and requires another principle of explanation." (1)

Jung's association with Pauli would have only strengthened this impression of the meaning of quantum theory because Pauli was a firm believer in the conventional Copenhagen interpretation. Therefore since causal connections in these meaningful coincidences seem inconceivable, Jung wants to move in the direction of an acausal principle, a kind of "meaningful cross-connection" between causal chains of events. (2)

He reviews the history of similar ideas from Albertus Magnus in the Middle Ages to Schopenhauer, to Paul Kammerer and J.P. Rhine in recent times. Rhine's work, statistically demonstrating extra-sensory perception by guessing cards over various distances in space and time, suggested to Jung that "the fact that distance has no effect in principle shows that the thing in question cannot be a phenomenon of force or energy... We have no alternative but to assume that distance is psychically variable, and may in certain circumstances be reduced to vanishing point by a psychic condition." (3) He concludes, "We must give up at the outset all explanations in terms of energy, which amounts to saying that events of this kind cannot be considered from the point of view of causality, for causality presupposes the existence of space and time in so far as all observations are ultimately based on bodies in motion." (4) Therefore it would be best to look for an explanation by starting with "a criticism of our concepts of space and time on the one hand, and with the unconscious on the other." (5)

For Jung space and time are only apparently the properties of bodies in motion, and are essentially psychic in origin, and therefore it is not unthinkable that the deep contents of the collective unconscious, that is, the archetypes and the powerful energies connected with them, could effect them.

Jung had been puzzling over the question of synchronicity for a long time, and he cites one of his earlier conclusions: "'Causality is only one principle and psychology essentially cannot be exhausted by causal methods only, because the mind (=psyche) lives by aims as well."' He goes on to comment on this passage: "Psychic finality rests on a 'pre-existent' meaning which becomes problematical only when it is an unconscious arrangement. In that case we have to suppose a 'knowledge' prior to all consciousness. Hans Driesch comes to the same conclusion (Die ‘Seele’ als elementarer Naturfaktor)." (6)

Somehow there must be something in the unconscious like an "a priori knowledge." (7) In some way the unconscious must become activated by intent or fear or hope, or some other strong emotion, and this activation is accompanied by a lowering of the level of consciousness and leads to the relativization of space and time. The resulting coincidence of inner subjective state and outer object is brought about not by causality, but by meaning or even "transcendental meaning."

Jung finds historical parallels to this kind of meaning in the Chinese idea of Tao which, too, can be understood as meaning. The Taoist "Nothing" "is evidently 'meaning' or 'purpose,' and it is only called Nothing because It does not appear in the world of the senses, but is only its organizer." (8) Jung also cites Agrippa von Nettesheim's inborn knowledge in living organisms which he sees taken up again by Driesch. (9) And he comments: "Whether we like it or not, we find ourselves in this embarrassing position as soon as we begin seriously to reflect on the teleological processes in biology or to investigate the compensatory function of the unconscious, not to speak of trying to explain the phenomenon of synchronicity. Final causes, twist them how we will, postulate a foreknowledge of some kind. It is certainly not a knowledge that could be connected with the ego, and hence not a conscious knowledge as we know it, but rather a self-subsistent 'unconscious' knowledge which I would prefer to call 'absolute knowledge."' (10) For Johannes Kepler the very fact that flowers have a definite color and number of petals points to an "instinctus divinus, rationis particeps." (11)

In short, in earlier ages there had always been a principle parallel to causality, but the rise of modern science had pushed it out of consciousness. Synchronicity points to "self-subsistent meaning" outside the realm of the ego, and is akin to Plato's forms, or formal factors in nature. Synchronicity "ascribes to the moving body a certain psychoid property which, like space, time, and causality, forms a criterion of its behavior." (12) Such a view of synchronicity could help clarify the relationship between body and soul with its "causeless order" or "meaningful orderedness."

Jung goes on to reflect on a near death experience, and wonders if events of this kind indicate "whether there is some other nervous substrate in us, apart from the cerebrum, that can think and perceive, or whether the psychic processes that go on in us during loss of consciousness are synchronistic phenomena, i.e., events which have no causal connection with organic processes." (13) Such a substrate might be related to the sympathetic nervous system. Bees, for example, have a highly developed dance language which is probably unconscious and connected with the sympathetic system, and indicates the "existence of transcerebral thought and perception." (14)

If this begins to remind us of Sheldrake's formative causation, the impression is only strengthened when Jung writes, "On the organic level it might be possible to regard biological morphogenesis in the light of the synchronistic factor." (15) And then he goes on to bring forward the case of radioactive decay, which has suggested to certain physicists that the ultimate laws of nature are not even causal. Jung therefore concludes that synchronicity, understood as a psychoid factor, should be added to the classical triad of space, time and causality. It is the manifestation of a deeper and wider principle of "acausal orderedness" which embraces "a priori factors such as the properties of natural numbers, the discontinuity of modern physics, etc." (16) It is in synchronicity that this more general acausal orderedness, becomes observed.

Jung saw that numbers were not just artifacts of the conscious mind, but had a deeper significance, a mysterious numinous aspect, which is why they appeared so frequently in divinization procedures like that of the I Ching, which he felt was based on ideas similar to that of synchronicity. Number was, therefore, connected to synchronicity. It brought order and had an archetypal foundation, and so Jung defined it as an "archetype of order." (17) Number appeared, as well, in the symbols of the self that Jung called mandalas that often have a four-fold structure, or some multiple of four. Number seems to be used by the unconscious to create order.

Near the end of his life Jung realized there was more here to explore than he would ever have the opportunity to do himself, so he gave the task to one of his close colleagues, Marie-Louise von Franz, and she developed these ideas in Number and Time, and explored the notion of synchronicity in a series of essays that were eventually collected under the title of Psyche and Matter.

The psyche cannot be reduced to the ego. It embraces a much wider reality that Jung called the collective unconscious, and the lowest level of that unconscious is nature. Therefore, when the deep levels of the unconscious become activated, it is not surprising that synchronistic events would occur. These events, in turn, could be looked upon as empirical evidence that there is a unity underlying psyche and matter, a unity of existence that Jung called the unus mundus. (18) The world of the physicist and the psychologist is ultimately the same world, and the empirical world around us is somehow based on a "transcendental background." (19) Matter and psyche are rooted in this unus mundus which is a "potential structure" which becomes activated in synchronistic events which connect the inner and outer worlds by way of meaning. (20) Synchronistic events are, as we have seen, manifestations of the wider principle of acausal orderedness.

This helps us to understand why mathematical theories, which are often born out of intuitions coming from deep in the psyche, can be applied to explain physical realities. Von Franz brings forward various eastern and western examples that suggest "that the unconscious is able spontaneously to produce mathematical structures consisting of natural numbers, and even in certain cases, matrices, in order to express a form of orderedness." (21) In short, "numbers appear to represent both an attribute of matter and the unconscious foundation of our mental processes. For this reason, number forms, according to Jung, that particular element that unites the realms of matter and psyche... As the active ordering factor, it represents the essence of what we generally term 'mind'." (22) Jung relates the nature of spirit to "a spontaneous principle of movement in the unconscious psyche which engenders, autonomously manipulates, and orders inner images" and von Franz comments: "Number is, as it were, the most accessible primitive manifestation of this transcendental spontaneous principle of movement in the psyche." (23)

Von Franz feels that there are striking similarities between the three-fold structure of the genetic code, and the structure of the I Ching, which point to how number regulates psyche and matter. In all this the archetype is not viewed as the cause of synchronistic events. Rather, "acausal orderedness appears or manifests itself in these phenomena.. The archetype is the structure, which can be perceived through introspection, of an a priori psychic orderedness." (24) Then she comes to the question that we saw preoccupying Sheldrake about the origin of the forms or laws of nature, but this time it is a question of the origin of the very similar archetypes, and she responds: "In Jung's view, the basic structures were always there, but within them ever-new acts of creation are taking place. Jung came to the view that the archetype is something we can never get beyond; it is the ultimate, the most fundamental structure of our psychic being, which we cannot transcend." (25)