Synchronicity (German: Synchronizität) is a concept first introduced by analytical psychologist Carl G. Jung "to describe circumstances that appear meaningfully related yet lack a causal connection." Jung held that to ascribe meaning to certain acausal coincidences can be a healthy, even necessary, function of the human mind—principally, by way of bringing important material of the unconscious mind to attention. This further developed into the view that there is a philosophical objectivity or suprasubjectivity to the meaningfulness of such coincidences, as related to the collective unconscious.
During his career, Jung furnished several different definitions of the term, defining synchronicity as "a hypothetical factor equal in rank to causality as a principle of explanation", "an acausal connecting principle", "acausal parallelism", and as the "meaningful coincidence of two or more events where something other than the probability of chance is involved". Though introducing the concept as early as the 1920s, Jung gave a full statement of it only in 1951 in an Eranos lecture. In 1952, Jung published a paper titled "Synchronicity: An Acausal Connecting Principle" (German: "Synchronizität als ein Prinzip akausaler Zusammenhänge") in a volume which also contained a related study by the physicist and Nobel laureate Wolfgang Pauli, a close collaborator who held a "critical, yet constructive and genuinely positive view of Jung and his ideas".
Jung's view was that, just as causal connections can provide a meaningful understanding of the psyche and reality, so too may acausal connections. 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. The three identifying aspects of synchronistic events are (a) meaningful coincidence, (b) acausal connection, and (c) numinosity—the last of which has drawn the most criticism upon the entire concept. Jung similarly proposed three categories of synchronistic phenomena, as when there is either (1) a meaningful correspondence between a mental state and a simultaneous physical event, (2) a meaningful correspondence between a mental state and a physical event outside the individual's perception, or (3) a meaningful correspondence between a mental state and some future event.
Jung used the concept in arguing for the existence of the paranormal, as did writer Arthur Koestler in his 1972 work The Roots of Coincidence. The concept was similarly taken up by the New Age movement. However, as it is scientifically neither testable nor falsifiable, synchronicity does not fall into the realm of empirical study. The main objection from a scientific standpoint is that synchronistic events are experimentally indistinguishable from ordinary coincidences. While a given observer may subjectively view a coincidence as meaningful, this does not necessitate assigning any objective meaning to the coincidence. Jung however, believed that meaning could be as rigorous and objective as logical thought by looking past personal feelings and instead to psychological elements that are held in common, yet he did not conduct objective studies in this regard based on observable mental states and scientific data. Mainstream science explains synchronicities and mere coincidences alike as underestimated chance events or spurious correlations which can be described by laws of statistics (e.g. by the law of truly large numbers) and confirmation biases. However, for lack of more sophisticated explanations coincidence can also be useful as kind of link to folk psychology and philosophy.
Moreover, it is considered that multiple meaningful coincidences contribute to the early formation of schizophrenic delusions . Distinguishing which of these synchronicities can be morbid, according to Jung, is a matter of interpretation–pathology, if any, lies in the reaction rather than the occurrence of synchronistic experiences. The International Dictionary of Psychoanalysis states that "it is important that the individual grasp [the] compensatory meaning" of a synchronistic event, in order for it to "enhance consciousness rather than merely build up superstitiousness".
Jung coined the term synchroncity as part of a lecture in May 1930, at first for use in discussing Chinese religious and philosophical concepts. His first major outline of the principle itself, however, was not until an Eranos conference lecture in 1951. This was soon followed by his monograph on the subject, Synchronicity: An Acausal Connecting Principle, published in 1952. Despite this, the roots of the concept formed part of his earlier work in the 1920s. Jung drew upon Chinese philosophy as well as the philosophies of Gottfried Leibniz, Johannes Kepler, and Arthur Schopenhauer. He points to Schopenhauer as providing an early conception of synchronicity in the quote:
All the events in a man's life would accordingly stand in two fundamentally different kinds of connection: firstly, in the objective, causal connection of the natural process; secondly, in a subjective connection which exists only in relation to the individual who experiences it, and which is thus as subjective as his own dreams.— Arthur Schopenhauer, "Die Transzendentale Spekulation über die anscheinende Absichtlichkeit im Schicksal des Einzelnen" (1851)
Other notable precursors and influences can be found in the theological concept of correspondences, sympathetic magic, Chinese classic texts, Taoist concepts, I Ching divination, Leibnizian monadology, astrology, and alchemy.
In analytical psychology, the recognition of seemingly-meaningful coincidences is a mechanism by which unconscious material is brought to the attention of the conscious mind. A harmful or developmental outcome can then result only from the individual's response to such material. Jung proposed that the concept could have psychiatric use in mitigating the negative effects of over-rationalisation and proclivities towards mind–body dualism.
Analytical psychology considers modern modes of thought to rest upon the pre-modern and primordial structures of the psyche. Causal connections thus form the basis of modern worldviews, and connections which lacks causal reasoning are seen as chance. This chance-based interpretation, however, is incongruent with the primordial mind which instead interprets this category as intention. The primordial framework in fact places emphasis on these connections, just as the modern framework emphasizes causal ones. In this regard, causality, like synchronicity, is a human interpretation imposed onto external phenomena. Primordial modes of thought are however, according to Jung, necessary constituents of the modern psyche that inevitably protrude into modern life—providing the basis for meaningful interpretation of the world by way of meaning-based connections. Just as the principles of psychological causality provide meaningful understanding of causal connections, so too the principle of synchronicity attempts to provide meaningful understanding of acasual connections. Jung placed synchronicity as one of three main conceptual elements in understanding the psyche:
- Psychological causality, as understood in Freudian theory, by which repressed libidinal energy is discharged across the psyche in response to principles of cause and effect—though Jung broadened this to a more generalized mental energy that is "particular to the unfolding of the individual psyche"
- Psychological teleology, by which self-actualisation is an element of the psyche as potential
- Psychological synchronicity, or meaningful chance, by which the potential for self-actualisation is either enhanced or negated
Jung felt synchronicity to be a principle that had explanatory power towards his concepts of archetypes and the collective unconscious.[i] It described a governing dynamic which underlies the whole of human experience and history—social, emotional, psychological, and spiritual. The emergence of the synchronistic paradigm was a significant move away from Cartesian dualism towards an underlying philosophy of double-aspect theory. Some argue this shift was essential in bringing theoretical coherence to Jung's earlier work.[ii]
Philosophy of science
Jung held that there was both a philosophical and scientific basis for synchronicity. He identified the complementary nature of causality and acausality with Eastern sciences and protoscientific disciplines, stating "the East bases much of its science on this irregularity and considers coincidences as the reliable basis of the world rather than causality. Synchronism is the prejudice of the East; causality is the modern prejudice of the West". Contemporary scholar L. K. Kerr writes:
Jung also looked to modern physics to understand the nature of synchronicity, and attempted to adapt many ideas in this field to accommodate his conception of synchronicity, including the property of numinosity. He worked closely with Nobel Prize winning physicist Wolfgang Pauli and also consulted with Albert Einstein. The notion of synchronicity shares with modern physics the idea that under certain conditions, the laws governing the interactions of space and time can no longer be understood according to the principle of causality. In this regard, Jung joined modern physicists in reducing the conditions in which the laws of classical mechanics apply.
It is also pointed out that, since Jung took into consideration only the narrow definition of causality—only the efficient cause—his notion of acausality is also narrow and so is not applicable to final and formal causes as understood in Aristotelian or Thomist systems. Either the final causality is inherent in synchronicity, as it leads to individuation; or synchronicity can be a kind of replacement for final causality. However, such finalism or teleology is considered to be outside the domain of modern science.
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Jung's use of the concept in arguing for the existence of paranormal phenomena has been widely considered pseudoscientific by modern scientific scepticism. Furthermore, his collaborator Wolfgang Pauli objected to his dubious experiments of the concept involving astrology—which Jung believed to be supported by the laboratory experiments behind the uncertainty principle's formulation. Jung similarly turned to the works of parapsychologist Joseph B. Rhine to support a connection between synchronicity and the paranormal. In his book Synchronicity: An Acausal Connecting Principle, Jung wrote:
How are we to recognize acausal combinations of events, since it is obviously impossible to examine all chance happenings for their causality? The answer to this is that acausal events may be expected most readily where, on closer reflection, a causal connection appears to be inconceivable.… It is impossible, with our present resources, to explain ESP [extrasensory perception], or the fact of meaningful coincidence, as a phenomenon of energy. This makes an end of the causal explanation as well, for "effect" cannot be understood as anything except a phenomenon of energy. Therefore it cannot be a question of cause and effect, but of a falling together in time, a kind of simultaneity. Because of this quality of simultaneity, I have picked on the term "synchronicity" to designate a hypothetical factor equal in rank to causality as a principle of explanation.
Roderick Main, in the introduction to his 1997 book Jung on Synchronicity and the Paranormal, wrote:
The culmination of Jung's lifelong engagement with the paranormal is his theory of synchronicity, the view that the structure of reality includes a principle of acausal connection which manifests itself most conspicuously in the form of meaningful coincidences. Difficult, flawed, prone to misrepresentation, this theory none the less remains one of the most suggestive attempts yet made to bring the paranormal within the bounds of intelligibility. It has been found relevant by psychotherapists, parapsychologists, researchers of spiritual experience and a growing number of non-specialists. Indeed, Jung's writings in this area form an excellent general introduction to the whole field of the paranormal.
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.
French writer Émile Deschamps claims in his memoirs that, in 1805, he was treated to some plum pudding by a stranger named Monsieur de Fontgibu. Ten years later, the writer encountered plum pudding on the menu of a Paris restaurant and wanted to order some, but the waiter told him that the last dish had already been served to another customer, who turned out to be de Fontgibu. Many years later, in 1832, Deschamps was at a dinner and once again ordered plum pudding. He recalled the earlier incident and told his friends that only de Fontgibu was missing to make the setting complete—and in the same instant, the now-senile de Fontgibu entered the room, having got the wrong address.
After describing some examples, Jung wrote: "When coincidences pile up in this way, one cannot help being impressed by them – for the greater the number of terms in such a series, or the more unusual its character, the more improbable it becomes.":91
In his book Thirty Years That Shook Physics – The Story of Quantum Theory (1966), George Gamow writes about Wolfgang Pauli, who was apparently considered a person particularly associated with synchronicity events. Gamow whimsically refers to the "Pauli effect", a mysterious phenomenon which is not understood on a purely materialistic basis, and probably never will be. The following anecdote is told:
It is well known that theoretical physicists cannot handle experimental equipment; it breaks whenever they touch it. Pauli was such a good theoretical physicist that something usually broke in the lab whenever he merely stepped across the threshold. A mysterious event that did not seem at first to be connected with Pauli's presence once occurred in Professor J. Franck's laboratory in Göttingen. Early one afternoon, without apparent cause, a complicated apparatus for the study of atomic phenomena collapsed. Franck wrote humorously about this to Pauli at his Zürich address and, after some delay, received an answer in an envelope with a Danish stamp. Pauli wrote that he had gone to visit Bohr and at the time of the mishap in Franck's laboratory his train was stopped for a few minutes at the Göttingen railroad station. You may believe this anecdote or not, but there are many other observations concerning the reality of the Pauli Effect! 
Jung's theory of synchronicity is nowadays regarded as pseudoscientific, as it is not based on experimental evidence, and its explananda are easily accounted for by our current understanding of probability theory and human psychology.
Jung believed life was not a series of random events but rather an expression of a deeper order, which he and Pauli referred to as Unus mundus. This deeper order led to the insights that a person was both embedded in a universal wholeness and that the realisation of this was more than just an intellectual exercise, but also had elements of a spiritual awakening. From the religious perspective, synchronicity shares similar characteristics of an "intervention of grace". Jung also believed that in a person's life, synchronicity served a role similar to that of dreams, with the purpose of shifting a person's egocentric conscious thinking to greater wholeness.
Mathematics and statistics
Jung and his followers (e.g., Marie-Louise von Franz) share in common the belief that numbers are the archetypes of order, and the major participants in synchronicity creation. This hypothesis has implications that are relevant to some of the “chaotic” phenomena in nonlinear dynamics. Dynamical systems theory has provided a new context from which to speculate about synchronicity because it gives predictions about the transitions between emergent states of order and nonlocality. This view, however, is not part of mainstream mathematical thought.
Mainstream mathematics argues that statistics and probability theory (exemplified in, e.g., Littlewood's law or the law of truly large numbers) suffice to explain any purported synchronistic events as mere coincidences. The law of truly large numbers, for instance, states that in large enough populations, any strange event is arbitrarily likely to happen by mere chance. However, some proponents of synchronicity question whether it is even sensible in principle to try to evaluate synchronicity statistically. Jung himself and von Franz argued that statistics work precisely by ignoring what is unique about the individual case, whereas synchronicity tries to investigate that uniqueness.
Social and behavioural science
In psychology and cognitive science, confirmation bias is a tendency to search for or interpret new information in a way that confirms one's preconceptions, and avoids information and interpretations that contradict prior beliefs. It is a type of cognitive bias and represents an error of inductive inference, or is a form of selection bias toward confirmation of the hypothesis under study, or disconfirmation of an alternative hypothesis. Confirmation bias is of interest in the teaching of critical thinking, as the skill is misused if rigorous critical scrutiny is applied only to evidence that challenges a preconceived idea, but not to evidence that supports it.
Charles Tart sees danger in synchronistic thinking: "This danger is the temptation to mental laziness.… [I]t would be very tempting to say, 'Well, it's synchronistic, it's forever beyond my understanding,' and so (prematurely) give up trying to find a causal explanation."
Upon initial publication, the work of Jung, such as The Interpretation of Nature and the Psyche, were received as problematic by his fellow psychologists. Fritz Levi, in his 1952 Neue Schweizer Rundschau (New Swiss Observations) review, critiqued Jung's theory of synchronicity as vague in determinability of synchronistic events, saying that Jung never specifically explained his rejection of "magic causality" to which such an acausal principle as synchronicity would be related. He also questioned the theory's usefulness.
In psychology and sociology, the term apophenia is used for the mistaken detection of a pattern or meaning in random or meaningless data. Skeptics, such as Robert Todd Carroll of the Skeptic's Dictionary, argue that the perception of synchronicity is better explained as apophenia. Primates use pattern detection in their form of intelligence, and this can lead to erroneous identification of non-existent patterns.
A famous example of this is the fact that human-face recognition is so robust, and based on such a basic archetype (i.e., two dots and a line contained in a circle), that human beings are very prone to identify faces in random data all through their environment, like the "man in the moon", or faces in wood grain, an example of the visual form of apophenia known as pareidolia.
Many people believe that the Universe, angels, other spirits, or God cause synchronicity. Among the general public, divine intervention is the most widely accepted explanation for these meaningful coincidences.
Research on the processes and effects of synchronicity is a subfield of psychological study. Modern scientific techniques, such as mathematical modeling, were used to observe chance correlations of synchronicities with Fibonacci time patterns.
As far as methodology is concerned, all empirical methods can be used to study synchronicity scientifically: quantitative, qualitative, and combination methods. Most studies of synchronicity, however, have been limited to qualitative approaches, which tend to collect data expressed in non-mathematical representations such as descriptions, placing less focus on estimating the strength and form of relationships.
On the other hand, skeptics (e.g. most psychologists) tend to dismiss the psychological experience of coincidences as just yet one more demonstration of how irrational people can be. Irrationality in this context means an association between the experience of coincidences and biased cognition in terms of poor probabilistic reasoning and a propensity for paranormal beliefs.
A survey (with 226 respondents) of the frequency of synchronicity in clinical settings found that 44% of therapists reported synchronicity experiences in the therapeutic setting; and 67% felt that synchronicity experiences could be useful for therapy. The study also points out ways of explanations of synchronicity:
For example, psychologists were significantly more likely than both counsellors and psychotherapists to agree that chance coincidence was an explanation for synchronicity, whereas, counsellors and psychotherapists were significantly more likely than psychologists to agree that a need for unconscious material to be expressed could be an explanation for synchronicity experiences in the clinical setting.
- Jung, Carl G. (1960). Synchronicity: An Acausal Connecting Principle. Routledge and Kegan Paul (published 1972). ISBN 978-0-7100-7397-6. (Also included in his Collected Works 8.)
- —— (1969). Archetypes and the Collective Unconscious. Princeton: Princeton University Press (published 1981). ISBN 978-0-691-01833-1.
- —— (1977). Jung on Synchronicity and the Paranormal: Key Readings. Routledge. ISBN 978-0-415-15508-3.
- Wilson, Robert Anton (1988). Coincidance: A Head Test.[ISBN missing]
- Sourrys, George (2021). The Synchronicity of Ulysses. Geno Publishing, ISBN 978-0645078381.
Philip K. Dick makes reference to, "Pauli's synchronicity", in his 1963 science-fiction novel, The Game-Players of Titan, in reference to pre-cognitive psionic abilities being interfered with by other psionic abilities such as psychokinesis: "an acausal connective event".
George Sourrys' 2021 novel The Synchronicity of Ulysses delves into the concept of synchronicity very deeply. In this novel he even explains what causes synchronicity, as part of the novel's overarching Theory of Everything.
- Black box theory
- Correlation does not imply causation – Refutation of a logical fallacy
- Emergence – Phenomenon in complex systems where interactions produce effects not directly predictable from the subsystems
- Leibniz’s Monadology as an assault on rationality
- Arthur Koestler’s The Paranormal about classification of coincidences – Hungarian-British author and journalist
- Ideas of reference and delusions of reference
- Look-elsewhere effect
- Multiple discovery – Hypothesis about scientific discoveries and inventions
- Paul Kammerer, seriality theory
- Post hoc ergo propter hoc – Fallacy of assumption of causality based on sequence of events
- Propinquity – Physical or psychological proximity between people
- Semiotics – The study of signs and sign processes
- Stigmergy – Social network mechanism of indirect coordination
- Superluminal communication
- Carl G. Jung (1960), Synchronicity: An Acausal Connecting Principle, Princeton University Press, 2012, p. 44.
- Liz Greene, Jung's Studies in Astrology: Prophecy, Magic, and the Qualities of Time, Routledge, 2018.
- Kerr, Laura K. (2013). "Definition: Synchronicity". In Teo, T. (ed.). Encyclopedia of Critical Psychology. Berlin, Heidelberg: Springer-Verlag.
- Campbell, Frances (2010). "Synchronicity". In Leeming, D.A.; Madden, K.; Marlan, S. (eds.). Encyclopedia of Psychology and Religion. Boston, MA: Springer. doi:10.1007/978-0-387-71802-6_678.
- Whitson, James Anthony (2008). "Thinking of(f) the Deep End: Semetsky and the Complicated Conversation". Complicity: An International Journal of Complexity and Education. 5 (1): 81–106.
- Tarnas, Richard (2006). Cosmos and Psyche. New York: Penguin Group. p. 50. ISBN 978-0-670-03292-1.
- Beitman, Bernard D. 2009. "Coincidence Studies: A Freudian Perspective". PsycCRITIQUES 55(49): Article 8. doi:10.1037/a0021474. S2CID 147210858.
- Diaonis, Persi; Mosteller, Fredrick (1989). "Methods of Studying Coincidences". Journal of the American Statistical Association. American Statistical Association. 84 (408): 853–861. JSTOR 2290058.
- Jung, Carl G.  2005. "Synchronicity". Pp. 91–98 in Jung on Synchronicity and the Paranormal, edited by R. Main. London: Taylor & Francis.
- Casement, Ann, "Who Owns Jung?" Archived 2016-12-31 at the Wayback Machine, Karnac Books, 2007. ISBN 1-85575-403-7. Cf. page 25.
- Jung, Carl G.  1993. Synchronicity: An Acausal Connecting Principle. Bollingen, CH: Bollingen Foundation. ISBN 978-0-691-01794-5. (Since included in his Collected Works 8.).
- Jung, Carl Gustav, and Wolfgang Ernst Pauli.  1955. The Interpretation of Nature and the Psyche, translated from German Naturerklärung und Psyche.
- Main, Roderick. 2000. "Religion, Science, and Synchronicity". Harvest: Journal for Jungian Studies 46(2):89–107. Archived from the original on 8 December 2006.
- Hogenson, G. B. (2008). "The Innermost Kernel: Depth Psychology and Quantum Mechanics. Wolfgang Pauli's Dialogue with C.G. Jung, by Gieser, Suzanne". Journal of Analytical Psychology. 53 (1): 127–136. doi:10.1111/j.1468-5922.2007.00705_1.x.
- Bishop, Paul C. (2008). "The Timeliness and Timelessness of the 'Archaic': Analytical Psychology, 'Primordial' Thought, Synchronicity". Journal of Analytical Psychology. 53 (4): 501–23. doi:10.1111/j.1468-5922.2008.00743.x.
- Tart, Charles (1981). "Causality and Synchronicity – Steps Toward Clarification". Journal of the American Society for Psychical Research. 75: 121–141. Archived from the original on 2015-09-24.
- Bonds, Christopher, 2002. "Synchronicity". Pp. 240–42 in The Skeptic Encyclopedia of Pseudoscience 1, edited by M. Shermer, and P. Linse. p. 241.
- Rushnell, S. (2006). When God winks. Atria Books.
- Koestler, Arthur 1973. The Roots of Coincidence. Vintage. ISBN 0-394-71934-4.
- F. David Peat, 1999, Time, Synchronicity and Evolution
- Navin, John. 2014. "Why Coincidences, Miracles And Rare Events Happen Every Day" (interview with David Hand). Forbes. Archived 2017-07-29 at the Wayback Machine.
- Radford, Benjamin. 4 February 2014. "Synchronicity: Definition & Meaning". Live Science. Retrieved 25 June 2020.
- Van Elk, Michiel; Friston, Karl; Bekkering, Harold (2016). "The Experience of Coincidence: An Integrated Psychological and Neurocognitive Perspective". The Challenge of Chance. The Frontiers Collection. pp. 171–185. doi:10.1007/978-3-319-26300-7_9. ISBN 978-3-319-26298-7.
- Morrison, P. D.; Murray, R. M. (2009). "From Real-World Events to Psychosis: The Emerging Neuropharmacology of Delusions". Schizophrenia Bulletin. 35 (4): 668–674. doi:10.1093/schbul/sbp049. PMC 2696381. PMID 19487337.
- Jung, Carl.  2019. "Letter to L. Kling" – via Carl Jung Depth Psychology.
- Robert Aziz, 1990. C. G. Jung's Psychology of Religion and Synchronicity, p. 191
- Beebe, John. "Synchronicity". International Dictionary of Psychoanalysis (1st ed.). Macmillan Reference USA. ISBN 9780028659947.
- Wolfgang Pauli in letter to Jung 1950
- Brach, Jean-Pierre, and Wouter J. Hanegraaff. (2006). "Correspondences". In Dictionary of Gnosis & Western Esotericism, edited by Wouter Hanegraaff.
- Robert Todd Carroll, "sympathetic magic" in The Skeptic's Dictionary
- Marie-Louise von Franz, Man and His Symbols (1964), p. 227
- Cambray Joe, (2005). The place of the 17th century in Jung's encounter with China. The Journal of Analytical Psychology 50(2):195-207. doi:10.1111/j.0021-8774.2005.00523.x
- Tacey, David (2009). "Mind and earth: Psychic Influence Beneath the Surface". Jung Journal: Culture & Psyche. Taylor & Francis. 3 (2): 15–32. doi:10.1525/jung.2009.3.2.15. JSTOR 10.1525/jung.2009.3.2.15.
- Brown, R. S. 2014. "Evolving Attitudes". International Journal of Jungian Studies 6(3):243–53.
- Arraj, James. 1996. "Synchronicity and Formal Causality". Ch. 8 in The Mystery of Matter: Nonlocality, Morphic Resonance, Synchronicity and the Philosophy of Nature of St. Thomas Aquinas. Archived 2015-05-22 at the Wayback Machine. ISBN 0-914073-09-5.
- Mansfield, Victor. 1995., Synchronicity, Science and Soul-Making: Understanding Jungian Synchronicity Through Physics, Buddhism, and Philosophy.
- Jung, Carl (1973). Synchronicity: An Acausal Connecting Principle (first Princeton/Bollingen paperback ed.). Princeton, New Jersey: Princeton University Press. p. 8. ISBN 978-0-691-15050-5.
- Jung, Carl. 2014 . "Synchronicity: An Acausal Connecting Principle", translated by R. F. C. Hull. Pp. 3373–509 in Collected Works of Carl Jung VIII.vii. East Sussex: Routledge. p. 3391.
- Main, Roderick (1997). Jung on Synchronicity and the Paranormal. Princeton University Press. p. 1.
- Jung, C.G. (1969). Synchronicity: An Acausal Connecting Principle. Princeton, New Jersey: Princeton University Press. ISBN 978-0-691-15050-5.
- Deschamps, Émile. 1872–74. Œuvres Complètes: Tomes I–VI, Reimpr. de l'ed. de Paris.
- Thirty Years That Shook Physics – The Story of Quantum Theory, George Gamow, p. 64, Doubleday & Co. Inc. New York, 1966
- Main, Roderick (2007). Revelations of Chance: Synchronicity as Spiritual Experience. The State University of New York Press.
- Von Franz, M.L. (1974). Number and Time: Reflections Leading toward a Unification of Depth Psychology and Physics. Northwestern University Press.
- Hogenson, G. B. (2005). The self, the symbolic and synchronicity: Virtual realities and the emergence of the psyche. Journal of Analytical Psychology, 50, 271–284. https://dx.doi.org/10.1111/j.0021-8774.2005.00531.x
- Lane, David, and Andrea Diem Lane. 2010. Desultory Descussation: Where Littlewood’s Law of Miracles meets Jung’s Synchronicity" Integral World. Archived 2014-06-26 at the Wayback Machine.
- Tim van Gelder, "Heads I win, tails you lose": A Foray Into the Psychology of Philosophy
- Bishop, Paul (2000). Synchronicity and Intellectual Intuition in Kant, Swedenborg, and Jung. The Edwin Mellen Press. pp. 59–62. ISBN 978-0-7734-7593-9.
- Brugger, Peter. 2001. "From Haunted Brain to Haunted Science: A Cognitive Neuroscience View of Paranormal and Pseudoscientific Thought". In Hauntings and Poltergeists: Multidisciplinary Perspectives, edited by J. Houran and R. Lange. North Carolina: McFarland & Company.
- Kernan, W. J.; Higby, W. J.; Hopper, D. L.; Cunningham, W.; Lloyd, W. E.; Reiter, L. (1980). "Pattern recognition of behavioral events in the nonhuman primate". Behavior Research Methods & Instrumentation. 12 (5): 524–534. doi:10.3758/BF03201828.
- Svoboda, Elizabeth (2007). "Facial Recognition – Brain – Faces, Faces Everywhere". New York Times. Archived from the original on 2017-05-11. Retrieved 2017-02-23.
- Sacco, R. G. 2019. "The Predictability of Synchronicity Experience: Results from a Survey of Jungian Analysts". International Journal of Psychological Studies 11:46–62. doi:10.5539/ijps.v11n3p46.
- Johansen, M. K., and M. Osman. 2015. "Coincidences: A fundamental consequence of rational cognition". New Ideas in Psychology 39:34-44.
- Roxburgh, Elizabeth C., Sophie Ridgway, and Chris A. Roe. 2016. "Synchronicity in the therapeutic setting: A survey of practitioners". Counselling and Psychotherapy Research 16(1):44–53. doi:10.1002/capr.12057.
- Roxburgh, Elizabeth. 2013. "An investigation into the prevalence and phenomenology of synchronicity experiences in the clinical setting"
- Dick, Philip K.  1992. The Game-Players of Titan (1st ed.). New York: Vintage Books. ISBN 0-679-74065-1. p. 128.
- Aziz, Robert. 1990. C.G. Jung's Psychology of Religion and Synchronicity (10th ed.). Albany: State University of New York Press. ISBN 978-0-7914-0166-8.
- —— 1999. "Synchronicity and the Transformation of the Ethical in Jungian Psychology". In Asian and Jungian Views of Ethics, edited by C. Becker. Greenwood. ISBN 978-0-313-30452-1.
- —— 2007. The Syndetic Paradigm: The Untrodden Path Beyond Freud and Jung. Albany: State University of New York Press. ISBN 978-0-7914-6982-8.
- —— 2008. "Foreword". In Synchronicity: Multiple Perspectives on Meaningful Coincidence, edited by L. Storm. Pari Publishing. ISBN 978-88-95604-02-2.
- Carey, Harriet. 1869. "Monsieur de Fontgibu and the Plum Pudding". In Echoes from the Harp of France. p. 174.
- Cederquist, Jan. 2010. Meaningful Coincidence. Times Publishing Ltd. ISBN 978-0-462-09970-5.
- Combs, Allan, and Mark Holland. 2001. Synchronicity: Through the Eyes of Science, Myth, and the Trickster. New York: Marlowe. ISBN 978-1-56924-599-6.
- Jaworski, Joseph. 1996. Synchronicity: the inner path of leadership. Berrett-Koehler Publishers Inc. ISBN 978-1-881052-94-4.
- Gieser, Suzanne. 2005. The Innermost Kernel. Depth Psychology and Quantum Physics. Wolfgang Pauli's Dialogue with C.G. Jung. Springer Verlag.
- Haule, John Ryan. 2010. Jung in the 21st Century: Synchronicity and science. Routledge. ISBN 978-0-203-83360-5.
- Koestler, Arthur. 1973. The Roots of Coincidence. Vintage. ISBN 978-0-394-71934-4.
- Main, Roderick. 2007. Revelations of Chance: Synchronicity as Spiritual Experience. Albany: State University of New York Press. ISBN 978-0-7914-7024-4.
- Mardorf, Elisabeth. Das kann doch kein Zufall sei (in German).
- Mansfield, Victor. 1995. Science, Synchronicity and Soul-Making. Open Court Publishing Company. ISBN 978-0-8126-9304-1.
- Peat, F. David. 1987. Synchronicity, The Bridge Between Matter and Mind. Bantam. ISBN 978-0-553-34676-3.
- Progoff, Ira. 1973. Jung, synchronicity, & human destiny: Noncausal dimensions of human experience. New York: Julian Press. ISBN 978-0-87097-056-6. OCLC 763819.
- Roth, Remo, F. 2011. Return of the World Soul, Wolfgang Pauli, C.G. Jung and the Challenge of Psychophysical Reality [unus mundus]. Pari Publishing.
- Sneller, Rico. 2020. Perspectives on Synchronicity, Inspiration, and the Soul. Cambridge Scholars. ISBN 978-1-5275-5505-1
- von Franz, Marie-Louise. 1980. On Divination and Synchronicity: The Psychology of Meaningful Chance. Inner City Books. ISBN 978-0-919123-02-1.
- Wilhelm, Richard. 1986. Lectures on the I Ching (Constancy and Change Bollingen ed.). Princeton University Press; reprint. ISBN 978-0-691-01872-0.
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