Quick Answer
Synchronicity is Jung's term for a meaningful coincidence between a psychic state and an external event, connected not by cause and effect but by meaning. It is not magic but an acausal connecting principle that Jung developed with physicist Wolfgang Pauli and grounded in the collective unconscious: when an archetype activates, it can manifest simultaneously in the psyche and in the external world.
Key Takeaways
- The precise definition: In CW 8, §850, Jung defined synchronicity as the coincidence of a psychic state with an external event "which appear as meaningful parallels", the key is meaning, not cause. The connection is acausal.
- The Pauli partnership: Jung developed the concept in collaboration with Nobel Prize physicist Wolfgang Pauli, who provided the quantum physics model of acausality, making synchronicity scientifically credible, not merely mystical.
- Three types: Contemporaneous (psyche and world event occurring simultaneously), spatially distant (corresponding event beyond perceptual range), and precognitive (corresponding to a future event).
- The archetype as bridge: Synchronicities cluster around activated archetypes; the archetype is the third factor that connects the inner psychic state and the outer physical event without causing either.
- Not superstition: Jung distinguished synchronicity carefully from magical thinking (the idea that thoughts cause events) and from supernatural intervention. The framework is psychological and philosophical, and it connects to the hermetic tradition's concept of cosmic correspondence.
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In 1952, Jung published one of the most philosophically ambitious papers of his career: "Synchronicity: An Acausal Connecting Principle," included in the joint volume with physicist Wolfgang Pauli, The Interpretation of Nature and the Psyche. The paper was, by his own admission, something he had been thinking about for decades and had hesitated to publish precisely because it invited ridicule from the scientific establishment.
The concept he was proposing was simple to state and immensely difficult to establish rigorously: some coincidences are not merely coincidental. Certain events that occur together without any causal link between them are nonetheless connected, connected by meaning rather than by cause. The connection does not run from psyche to world or from world to psyche. It runs, in some manner yet to be fully understood, through both simultaneously.
This is not astrology, not telepathy in the naive sense, and not magical thinking. Jung was careful to distinguish synchronicity from all three. What he was proposing was a fundamental revision of the Western scientific assumption that causality is the only legitimate explanatory principle, and he was doing so in company with one of the greatest physicists of the twentieth century.
The Concept and Its Precise Definition
The formal definition appears in CW 8, §850: "The simultaneous occurrence of a certain psychic state with one or more external events which appear as meaningful parallels to the momentary subjective state, and in certain cases, coincidences in time of two or more external events which are meaningfully equivalent, these observations justify the provisional assumption of an acausal principle of events."
Several elements of this definition require careful attention. "Simultaneous" does not necessarily mean at the exact same clock-second. It means occurring within the same temporal window of psychological experience, close enough in time that the relationship between them is felt as present rather than retrospective.
"Meaningful parallels" is the operative phrase. The external event is not just statistically improbable given the psychic state; it mirrors the psychic state with a precision that goes beyond chance. In the scarab incident, the event (a scarab beetle appearing at the window) precisely mirrors the content of the patient's dream (receiving a golden scarab). The correspondence is specific, not general.
Acausality: The Central Philosophical Claim
"Acausal connecting principle" is the philosophical core of the concept. Jung was claiming that there exists a mode of connection between events that is neither causal (A produces B) nor teleological (B is caused by its future purpose) but is instead a relationship of simultaneity through shared meaning. This is not a mystical claim but a philosophical one: it challenges the sufficiency of causality as the sole explanatory principle for the natural world. Jung's warrant for making it came from two sources: his clinical observations and Wolfgang Pauli's quantum physics.
Jung had been collecting synchronistic events for over twenty years before publishing the essay. He described them in private correspondence, in seminar discussions, and in clinical case notes. The hesitation to publish was not uncertainty about the phenomenon but concern about the reception: synchronicity sat at the boundary of science, psychology, and philosophy, and could be dismissed as mysticism by any of the three fields.
The Pauli Collaboration: Physics Meets Depth Psychology
Wolfgang Pauli (1900-1958) is a significant figure in both the history of physics and the history of the synchronicity concept. He was the formulator of the exclusion principle (which earned him the 1945 Nobel Prize in Physics), a founder of quantum mechanics alongside Bohr and Heisenberg, and, from 1931, a patient and later a close intellectual correspondent of Jung's.
Pauli came to Jung in a state of psychological crisis following the breakdown of his first marriage. His dreams, which Jung supervised indirectly (having Pauli work initially with a younger female analyst before engaging directly), were among the richest and most complex Jung had encountered. They formed the basis for the long case study in Psychology and Religion (CW 11) and contributed substantially to Jung's thinking on mandala symbolism.
Why Quantum Physics Mattered for Synchronicity
The philosophical problem synchronicity had to overcome was simple: Western science since Newton had assumed that all events are connected causally. If the psyche cannot cause a beetle to appear, then the coincidence of dream and beetle is just coincidence. What quantum mechanics showed, and what Pauli's contribution made explicit, is that causality is not the only relationship between events at the subatomic level. Radioactive decay, for instance, has no prior cause that determines when it will occur. It is, in the strict sense, acausal. If acausality is a legitimate concept in physics, it is at least possible as a concept in psychology. Pauli's participation gave the concept scientific credibility it could not otherwise have claimed.
Pauli's contribution to the 1952 volume was an essay on Kepler and the transition from the Renaissance worldview to the mechanistic worldview of modern science. His argument was that the Hermetic and Neoplatonic concepts of sympathy (the interconnection of all things through shared qualities and correspondences) were not simply superseded by the causal-mechanistic model but were driven underground, only to re-emerge in disguised form in quantum mechanics' acknowledgement of non-local connections between particles.
This historical and philosophical framing aligned precisely with Jung's psychological claims. The synchronicity concept was, in their shared view, not a regression to pre-scientific thinking but a sophisticated attempt to re-integrate what the Enlightenment's strict causal model had excluded: the dimension of meaning in nature.
The Three Types of Synchronistic Events
In CW 8, §850, Jung distinguished three types of synchronistic phenomena, which differ primarily in their spatial and temporal relationship between the psychic state and the corresponding external event.
| Type | Description | Example |
|---|---|---|
| Contemporaneous | Psychic state coincides with external event at the same time | The scarab beetle appearing as the patient describes her scarab dream |
| Spatially Distant | Psychic state corresponds to event occurring beyond perceptual range, verified later | A dream of a relative's death that corresponds to the actual death, verified by news received afterward |
| Precognitive | Psychic state corresponds to a future event | A dream that depicts in specific detail an event that has not yet occurred |
The first type is the most clinically observable and the most easily documented. The second and third types raise more challenging epistemological questions, since they involve correspondence across space or time in ways that are difficult to rule out as retrospective interpretation. Jung acknowledged these challenges but argued that the pattern of occurrence was too consistent and too specific to be dismissed as memory distortion or confirmation bias.
The three types are united by the common element: a psychic state and an external event sharing a meaningful connection without any causal link between them. The spatial and temporal variations are secondary to this structural commonality.
The Scarab Beetle Incident: The Archetypal Synchronicity
The most often cited synchronicity in the literature is the one Jung used to introduce the concept in his 1952 essay. The anecdote appears in CW 8 and in various lecture contexts, and it is worth examining carefully because it illustrates not just the phenomenon but Jung's clinical use of it.
A female patient of Jung's was at a critical point in her analysis. She was, in his description, highly educated, psychologically sophisticated, and trapped in a form of intellectual rationalism that prevented her from engaging with the deeper symbolic material her analysis required. She had reached an impasse. During one session, she was describing a dream from the previous night in which she had received a golden scarab as a gift.
While she was speaking, Jung heard a tapping at the window of his consulting room. He opened it and found a rose-chafer beetle (Cetonia aurata), which is the closest equivalent to the Egyptian scarab that is found in Switzerland. He caught it and, returning to his patient, held it out to her: "Here is your scarab."
Why the Scarab Mattered: Archetypal Resonance
The golden scarab is one of the most ancient and symbolically loaded figures in the Western tradition. In Egyptian religion, the scarab (Scarabaeus sacer) was the sacred insect of Khepri, the god of the rising sun, and symbolised regeneration, resurrection, and the renewal of life from apparent death. For the patient who was psychologically stuck, unable to renew herself through the analytic work because of her excessive rationalism, the synchronistic appearance of the beetle at the moment she described her dream was a physical enactment of the symbol her unconscious had already produced. The effect, Jung reported, was a loosening of the therapeutic impasse: the rational framework that had resisted transformation was momentarily overwhelmed by the encounter with the numinous.
The clinical significance of this event extends beyond the anecdote. What the synchronicity accomplished was what the purely verbal analytic work had not: it placed the archetypal symbol in concrete, inescapable reality. The patient could not argue that the scarab was merely symbolic, a product of her subjective psychology, when it was sitting in Jung's hand. The boundary between inner and outer, which her rationalism had maintained as an absolute, momentarily dissolved.
Paul Kammerer and the Precursor Concept of Seriality
Paul Kammerer (1880-1926) was an Austrian biologist who, alongside his controversial biological research, compiled extensive records of what he called seriality: the tendency for similar events to occur in clusters without apparent causal connection. In Das Gesetz der Serie (The Law of Series, 1919), he documented hundreds of such clusters from his own experience and argued that they represented a fundamental property of nature, a "law of series" comparable to the law of gravity.
Kammerer's examples ranged from trivial (encountering the same name or number repeatedly in a single day) to more striking (finding that multiple events sharing a common quality clustered around particular temporal and spatial nodes). He proposed that seriality was a real natural phenomenon operating alongside causality, not through any physical force but through some form of immanent tendency toward pattern in the fabric of events.
Jung engaged with Kammerer's work seriously and acknowledged him as a precursor. But he drew a clear distinction between seriality and synchronicity. Kammerer's work was essentially phenomenological and statistical: he documented the occurrence of series without proposing an adequate explanation for them. His "law of series" is a description, not an explanation. He could not say why similar events cluster.
Jung's synchronicity concept added the psychological dimension that Kammerer's framework lacked: the activated archetype as the third factor connecting the events. In synchronicity, the series is not random, it clusters around a psychologically significant state or life moment. The archetype provides the explanatory link that Kammerer's seriality was missing.
J.B. Rhine and the Empirical Dimension
J.B. Rhine (1895-1980) established the parapsychology laboratory at Duke University in 1930 and conducted systematic experiments in extrasensory perception using Zener cards: simple cards displaying one of five symbols (circle, cross, square, star, wave). Subjects were asked to identify cards not visible to them, and Rhine compiled the results statistically.
His published findings showed that certain subjects performed consistently above the chance expectation of 20% accuracy, sometimes in ways that seemed statistically extraordinary. Rhine published his results in Extra-Sensory Perception (1934) and subsequent volumes, and his work attracted both significant scientific attention and sustained criticism regarding his experimental controls and statistical methods.
Jung cited Rhine's work in his synchronicity essay not as definitive proof but as empirical evidence pointing toward the reality of psychic phenomena. His use of Rhine was rhetorical and philosophical rather than strictly scientific: he wanted to establish that the hypothesis of synchronicity was not without empirical grounding, that there existed at least a body of experimental data suggesting that the psyche could interact with the external world in ways not mediated by sensory information or physical causation.
The Limits of Rhine's Evidence
Jung was cautious about overstating Rhine's findings. He noted that the Rhine experiments pointed toward the existence of psychic phenomena but did not explain them, and he was explicit that synchronicity was a "provisional assumption", a working hypothesis that organised the available evidence, not a proven law. This epistemic caution is characteristic of Jung's approach to the boundary areas of his work: he consistently refused the certainty that his more enthusiastic followers sometimes claimed on his behalf, and he refused with equal consistency the dismissal that the scientific mainstream preferred.
The Collective Unconscious as the Explanatory Framework
The most distinctive element of Jung's synchronicity theory, and the one that distinguishes it from Kammerer's seriality, Rhine's ESP research, and popular concepts of "meaningful coincidence," is the role of the collective unconscious and the archetypes as the explanatory framework.
Jung's claim was this: synchronistic events do not occur randomly. They cluster around psychologically significant moments, particularly moments when an archetype is strongly activated in the personal psyche. The activation of an archetype, through a dream, through a major life transition, through the analytic process, through creative work, appears to create conditions in which corresponding events in the external world become more likely.
The archetype is not causing the external events. The relationship is not causal but what Jung called unus mundus, one world: the hypothesis that the psychic and physical dimensions of reality are aspects of a single underlying continuum rather than two entirely separate substances. When an archetypal pattern is activated, it manifests in both dimensions simultaneously, because it belongs to neither exclusively.
Unus Mundus: One World Underlying Psyche and Matter
Jung borrowed the concept of unus mundus from the late medieval alchemist Gerhard Dorn, who used it to describe the underlying unity from which both matter and spirit arise. In the unus mundus framework, the synchronistic connection between a psychic event and a physical event is possible because both are expressions of the same underlying reality. This is not idealism (the claim that matter is a product of mind) or materialism (the claim that mind is a product of matter). It is a third position: that both mind and matter arise from something prior to either, and synchronicity is the point where that common ground briefly becomes visible.
Working with Synchronicity: The Practical Dimension
Jung's synchronicity concept is not merely theoretical. It has practical implications for how we relate to the coincidences that occur in a psychologically significant life.
Practice: The Synchronicity Journal
Keep a dedicated journal for recording coincidences that carry an unusual quality of meaning, those that stop you, that produce a sense of recognition, that seem to correspond precisely to something you were thinking, dreaming, or emotionally engaged with. For each entry: (1) Describe the inner state you were in (what you had been thinking, dreaming, or working through). (2) Describe the external event that paralleled it. (3) Identify the shared quality or symbol connecting them. (4) Note whether you were at a psychologically significant juncture (a decision, a transition, an analytic moment). Over time, the pattern of when synchronicities cluster will become visible, and that pattern is itself meaningful.
The practical attitude toward synchronicity Jung recommended was neither credulity nor dismissal. It was attentiveness: the capacity to notice when the external world seems to be responding to an inner movement, without immediately interpreting the response as either supernatural communication or mere chance.
This attentiveness is different from looking for signs and omens in every event. The hallmarks of a genuinely synchronistic event, as opposed to ordinary coincidence, are: a quality of numinosity (the event feels freighted with significance beyond its surface meaning), a specific correspondence to the current inner psychological state (not a general correspondence to life as a whole), and a degree of precision (the correspondence is detailed, not vague).
In clinical terms, synchronicities that occur during analysis are particularly significant because the analytic process specifically activates archetypal material. Jung's practice was to take note of such events and to bring them into the analytic discussion in the same way he brought dreams: as data from the unconscious, available for amplification and interpretation.
Synchronicity and the Hermetic Tradition
The concept of synchronicity did not emerge from nowhere. It has deep roots in the pre-scientific worldview that Western modernity displaced rather than refuted. The most immediate ancestor is the hermetic tradition's concept of sympatheia: the cosmic sympathy between all parts of the universe, the principle that everything is connected to everything else through shared qualities, correspondences, and participations.
Hermes Trismegistus, the legendary author of the Hermetic texts, articulated the foundational principle in the Emerald Tablet: "That which is above is as that which is below." This axiom describes a universe in which the macrocosm and the microcosm, the outer world and the inner life, the stars and the psyche, are reflections of each other. Every event in the outer world corresponds to something in the inner, and every inner movement can find its reflection in the outer, not because one causes the other but because both arise from the same underlying pattern.
This is precisely what synchronicity describes in psychological terms. Jung's innovation was to relocate the explanatory principle from cosmic metaphysics (the Hermetic tradition) to depth psychology (the collective unconscious and its archetypes). The phenomenon he was describing was the same phenomenon the Hermetic tradition had described for two thousand years. What changed was the language and the theoretical framework used to account for it.
Pauli's contribution to the 1952 volume drew out this historical connection explicitly. His essay traced the decline of the Hermetic worldview in the seventeenth century and its suppression by the mechanistic physics of Newton and Descartes, and argued that quantum mechanics was, in a certain sense, a scientific rediscovery of what the Hermetic tradition had always known: that nature cannot be understood through causality alone.
If you want to engage with the hermetic tradition's account of cosmic correspondence and its relationship to depth psychology as a living practice, the Hermetic Synthesis Course provides a structured introduction to these connections.
The World That Responds
The most significant practical implication of synchronicity is not that you can influence events by thinking about them. It is that the world is not indifferent. The universe does not consist of dead matter moving according to mechanical laws in a space that human meaning merely inhabits. At least some of the time, at least when the psyche is in a state of depth, the outer world and the inner world appear to be in conversation. That conversation is not always easy to hear or to understand. But the practice of learning to notice it, to take it seriously without inflating it, is one of the oldest and most serious forms of spiritual attention available to human beings.
Frequently Asked Questions
Synchronicity: An Acausal Connecting Principle. (From Vol. 8. of the Collected Works of C. G. Jung) (Jung Extracts) by Jung, C. G.
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What is synchronicity according to Jung?
Synchronicity is Jung's term for the coincidence of a psychic state with an external event that parallels it in a meaningful way, without the psychic state causing the external event. In CW 8, §850, he defined it as "the simultaneous occurrence of a certain psychic state with one or more external events which appear as meaningful parallels to the momentary subjective state." The key word is "acausal": the connection is through meaning, not through cause and effect.
What are the three types of synchronicity?
Jung identified three types. The first is contemporaneous: a psychic state coincides with an external event at the same time, with no causal link (the scarab incident is the classic example). The second is spatially distant: a psychic state corresponds to an event happening outside the perceiver's range of perception, verified only afterward. The third is temporal: a psychic state corresponds to a future event, involving what is commonly called precognition or premonition.
What was the scarab beetle incident?
Jung's most famous synchronicity example: a patient was describing a dream in which she received a golden scarab when Jung heard a tapping at his window. A rose-chafer beetle, the closest equivalent to a scarab in Switzerland, had flown there. Jung caught it and handed it to the patient. The event broke a therapeutic impasse by introducing the resurrection archetype, symbolised by the Egyptian scarab, into physical reality at the critical therapeutic moment.
What was Wolfgang Pauli's role in the synchronicity concept?
Wolfgang Pauli, Nobel Prize-winning physicist and a founder of quantum mechanics, was Jung's patient from 1931 and his intellectual collaborator on synchronicity. Their joint 1952 volume contained Jung's synchronicity essay and Pauli's essay on Kepler. Pauli provided the scientific grounding: quantum mechanics demonstrates that acausality is a legitimate concept in modern physics, not merely a mystical notion, because events like radioactive decay have no prior determining cause.
How is synchronicity different from coincidence?
Synchronicity differs from coincidence in two ways: it involves a meaningful connection between the inner and outer events, not merely a random overlap; and the meaning arises in relation to the experiencer's psychological state, particularly the activation of an archetype. Random coincidences are unremarkable because they carry no meaning relative to the person's inner life. Synchronistic events carry a numinous quality that distinguishes them from mere chance alignment.
What was Paul Kammerer's contribution to the synchronicity concept?
Paul Kammerer documented clusters of similar events occurring together without causal connection in "Das Gesetz der Serie" (1919). Jung acknowledged Kammerer as a precursor but distinguished synchronicity from seriality. Kammerer described the phenomenon statistically; Jung proposed a psychological explanation: the collective unconscious and its archetypes as the third factor connecting inner and outer events.
What are the Rhine ESP experiments Jung referenced?
J.B. Rhine at Duke University conducted Zener card experiments in which subjects attempted to identify cards not visible to them. His results showed statistically significant performance above chance. Jung cited Rhine's work to establish that synchronistic phenomena were at least statistically documentable rather than purely anecdotal. The experiments remain controversial scientifically, but Jung used them rhetorically rather than as definitive proof.
How does synchronicity relate to the collective unconscious?
In Jung's framework, synchronistic events cluster around activated archetypes. When an archetypal pattern is strongly active in the personal psyche, it can manifest simultaneously in the external world, not because it causes external events but because both the psychic event and the physical event are expressions of the same underlying archetypal pattern. The archetype, residing in the collective unconscious, is the third factor connecting the inner and outer.
Is synchronicity the same as magic or superstition?
No. Jung was not claiming that thought causes external events (magical thinking) or that coincidences carry personal messages from a supernatural agent (superstition). He was proposing that certain coincidences exhibit a structural connection between inner and outer that exceeds statistical probability. The framework is psychological and philosophical, challenging the sufficiency of causality as the sole explanatory principle, not claiming supernatural intervention.
How can I work with synchronicity in practice?
The practical approach is attentional rather than active: noticing coincidences that carry an unusual quality of meaning, particularly those occurring at psychologically significant moments. Recording them in a journal alongside dream material allows patterns to emerge. The goal is not to manufacture synchronicities but to develop the capacity to notice when the external world appears to be responding to an inner movement, and to take that correspondence seriously without inflating it.
What did Jung's astrological experiment attempt to demonstrate?
Jung conducted a study correlating the horoscopes of married couples, looking for statistically significant astrological conjunctions. He reported positive results and interpreted them synchronistically rather than causally: astrology works, in his view, not because the stars influence personality but because the moment of birth reflects the same archetypal configuration that characterises the person's psychology. The experiment remains controversial and has not been independently replicated with similar results.
Sources & References
- Jung, C.G. (1952). "Synchronicity: An Acausal Connecting Principle." In The Structure and Dynamics of the Psyche (Collected Works, Vol. 8). Princeton University Press.
- Jung, C.G., and Pauli, W. (1952). The Interpretation of Nature and the Psyche. Pantheon Books.
- Kammerer, P. (1919). Das Gesetz der Serie [The Law of Series]. Deutsche Verlags-Anstalt.
- Rhine, J.B. (1934). Extra-Sensory Perception. Boston Society for Psychical Research.
- Mansfield, V. (1995). Synchronicity, Science, and Soul-Making. Open Court.
- Main, R. (2004). The Rupture of Time: Synchronicity and Jung's Critique of Modern Western Culture. Brunner-Routledge.
- Beitman, B.D. (2016). Connecting with Coincidence: The New Science for Using Synchronicity and Serendipity in Your Life. Health Communications.