Carl Jung: The Scientist Who Mapped the Unconscious and Why Neuroscience Is Proving Him Right

In the winter of 1913, Carl Jung sat at his desk in Küsnacht, Switzerland, and did something no respectable scientist was supposed to do. He deliberately induced visions, sinking into a waking dream state and recording what emerged in a leather-bound notebook he called the Liber Novus — later published as the Red Book.

What he found disturbed him. Floods. The dead rising. A sea of blood covering Europe. This was months before the First World War began, and Jung initially feared he was losing his sanity.

Later, he reframed it as the beginning of his most important work: an investigation into the deepest layers of the psyche. There, imagery was not random but structured — organised around patterns he called archetypes, appearing with remarkable consistency across the myths, dreams, and visions of every culture in recorded history.

For most of the twentieth century, this work sat in an uncomfortable space between science and something harder to categorise. Freud dismissed him. Behaviourists ignored him. Neuroscientists had no tools to examine his claims.

But in 2025, a landmark paper in Neuroscience of Consciousness, co-authored by Robin Carhart-Harris, proposed a formal neuroscientific framework for Jungian archetypes. Its argument: archetypes are not mystical relics but eigenmodes of deep brain activity — recurring patterns of neural organisation that shape imagination, myth, and human meaning-making. Jung was not a mystic. He was a scientist studying something his era had no tools to measure. The tools are beginning to arrive.

From Freud’s Heir to Independent Scientist

Carl Gustav Jung was born on 26 July 1875 in Kesswil, a village on Lake Constance in Switzerland. His father was a pastor, and Jung’s childhood was shaped by the tension between religious doctrine and what seemed to him the far darker, more complex reality of human experience.

He became a psychiatrist almost by accident. Choosing his medical specialisation at the University of Basel, he opened Krafft-Ebing’s psychiatry textbook one evening and found it described exactly the territory he had always been most curious about — the intersection of mind, body, and the border between sanity and its dissolution.

In 1900 he joined the Burghölzli clinic in Zurich under Eugen Bleuler, who coined the term schizophrenia. There Jung developed his word association test — a diagnostic technique in which delays and unexpected responses to stimulus words reveal hidden complexes in the unconscious. The work was rigorous, measurable, and publishable. It also brought him to Freud’s attention.

Their collaboration began in 1907 with a thirteen-hour conversation at Freud’s Vienna apartment. It became one of the most consequential — and most catastrophically failed — partnerships in the history of psychology. Freud saw Jung as his intellectual heir and designated successor.

But Jung disagreed fundamentally with the primacy Freud placed on sexuality as the source of unconscious motivation. He also grew uneasy with Freud’s insistence that psychoanalytic theory was a finished system to be defended rather than questioned.

The break came in 1912, when Jung published Wandlungen und Symbole der Libido. In it, he reinterpreted libido as general psychic energy rather than specifically sexual energy, and proposed that mythological imagery in patients’ dreams reflected something inherited — a deeper layer of the unconscious shared across the species. Freud regarded it as betrayal. Their correspondence ended acrimoniously, and Jung’s defining work began.

The Architecture of the Psyche

Jung’s model of the psyche is more structured than its popular reputation suggests. The outermost layer is consciousness — the aware, purposive mind we identify as ourselves. At its centre is the ego, the sense of personal identity. But the ego is not the whole psyche; it is a small island in a much larger sea.

Beneath it lies the personal unconscious — repressed experiences, forgotten memories, and emotionally charged complexes. This is roughly the territory Freud described. For Jung it was real and important, but not the most interesting level.

Deeper still lies the collective unconscious — a layer that is not personally acquired but inherited, the product of millions of years of human evolution. It is encoded not in specific memories but in the patterns and tendencies of mental life itself.

The collective unconscious manifests in dreams, myths, and religious imagery — in narrative patterns appearing across cultures that never had contact: the Hero, the Great Mother, the Trickster, the Shadow, the Wise Old Man. Jung called these recurring patterns archetypes.

Crucially, he distinguished the archetype itself — a formal tendency, inaccessible to direct observation — from the archetypal image, the specific cultural content through which it appears. The Hero archetype is universal; the specific hero (Gilgamesh, Odysseus, Luke Skywalker) is culturally specific. The pattern is inherited; the content is acquired. This distinction makes his claims far more testable than a naive reading suggests.

The most important archetypes for personal development are the Shadow — the disowned aspects of the self, projected onto others; the Anima and Animus — the contrasexual aspects of the psyche; and the Self — the central archetype of wholeness and the goal of individuation, the lifelong integration of unconscious material into consciousness. This idea of an inherited psychic inheritance connects directly to modern work on genetic memory and how experience may echo across generations.

What the Neuroscience Now Says: Archetypes as Neural Eigenmodes

The 2025 paper by McGovern, Aqil, Atasoy, and Carhart-Harris in Neuroscience of Consciousness is the most rigorous attempt yet to translate Jungian theory into neuroscience. Its central proposal: archetypes can be understood as eigenmodes of the deep brain — recurring patterns of neural activity arising from the brain’s intrinsic connectivity rather than from specific experiences.

Its theoretical basis is the Free Energy Principle, developed by Karl Friston, and Predictive Processing theory — the model of the brain as a prediction machine that constantly generates hypotheses about sensory input and updates them against prediction errors. The brain is not a passive receiver but an active modeller of the world.

The authors propose an interplay between three neural domains in generating archetypal experience: the high-level cortex, producing abstract narrative and symbol; the sensory cortex, providing perceptual imagery; and subcortical affective systems, providing the emotional charge that makes such imagery feel numinous — significant beyond its surface.

When these systems interact in altered states — deep meditation, psychedelic experience, fever dreams, near-death states — they produce experiences matching the archetypal encounters Jung collected from patients and world mythology. The paper frames the collective unconscious not as a mystical shared mind but as a consequence of all human brains being built to the same evolutionary specification.

This does not prove Jung right in every detail. It demonstrates that his core intuitions — that the unconscious has structure, that the structure is partly inherited, and that it manifests in recognisable cross-cultural patterns — are consistent with modern neuroscience and have a plausible mechanism. As Carhart-Harris put it in discussing the work, proposing that archetypes correspond to neural eigenmodes suggests that what Jung called the collective unconscious may be better understood as the collective architecture of the human brain.

Separately, a 2025 review in the International Journal of Jungian Studies, examining Gary Clark’s Carl Jung and the Evolutionary Sciences, noted the convergence between analytical psychology and evolutionary biology. It argued archetypes can be understood as genetically encoded predispositions — analogous to the innate releasing mechanisms described by the ethologist Konrad Lorenz — shaped by natural selection for social coordination, threat detection, and meaning-making.

Synchronicity: The Most Controversial Proposal

Of all Jung’s ideas, synchronicity is the most contested — and, from a physics perspective, the most interesting. He defined it as an acausal connecting principle: the meaningful coincidence of an inner psychic event and an outer physical event that are not causally related, yet whose connection cannot be dismissed as pure chance.

His most famous example came from his clinic. A patient was describing a dream of a golden scarab — an Egyptian symbol of rebirth — when Jung heard tapping at the window. He opened it to find a rose chafer beetle, the closest central-European equivalent of a scarab, which had flown toward the light. He handed it to her, and her rigid rationalism broke open, allowing the therapy to progress.

What is scientifically striking is that Jung developed synchronicity in dialogue with Wolfgang Pauli — the Nobel Prize-winning physicist behind the exclusion principle and a founder of quantum mechanics. Pauli was in analysis with Jung for years.

Their correspondence, published as The Interpretation of Nature and the Psyche in 1952, is one of the strangest collaborations in the history of science: a psychiatrist and a quantum physicist jointly asking whether the non-causal correlations of quantum mechanics — the entangled particles Einstein called “spooky action at a distance” — might have a psychological analogue.

Neither claimed to solve it. What they did was identify a genuine gap in their era’s worldview: the assumption that all meaningful connections must be causal, and anything non-causal must be random. Quantum mechanics had already shown this false at the physical level. Whether it holds at the psychological level remains open. For what entanglement actually implies about reality, see our article on quantum entanglement, the mystery at the heart of quantum mechanics.

The Red Book: A Scientist’s Descent

The visions Jung recorded between 1913 and roughly 1930 became the Liber Novus, or Red Book — a large, hand-illustrated folio he kept private for his entire life. It was not published until 2009, nearly half a century after his death.

For decades, critics used the book to argue Jung had strayed from science into mysticism. Its publication complicated that picture. What it revealed was a disciplined, systematic self-experiment — Jung deliberately entering altered states and documenting them with the same rigour he had once applied to the word association test.

He called the method active imagination: consciously engaging unconscious imagery while remaining lucid enough to observe it. Strikingly, this is close to what modern psychedelic and meditation researchers now do under laboratory conditions, using brain imaging to study the same territory Jung mapped by hand.

The Red Book, in other words, was not a departure from his science. It was his laboratory notebook — from an experiment for which the instruments would not exist for another century.

What Scientists Say

“By proposing that archetypes correspond to neural eigenmodes, we are suggesting that what Jung called the collective unconscious may be better understood as the collective architecture of the human brain.”
— Robin Carhart-Harris, Professor of Neurology and Psychiatry, UC San Francisco; co-author, Neuroscience of Consciousness (2025)

The psychiatrist Anthony Stevens, author of Archetype: A Natural History of the Self, has long argued that Jung’s hypothesis of a genetically inherited collective unconscious is entirely consistent with contemporary evolutionary biology, and can be reformulated as evolved psychological mechanisms — innate predispositions shaped by natural selection.

The Jungian analyst James Hollis has made a subtler point: that Jung consistently refused to separate what we know from what we are, insisting the knower cannot be subtracted from the knowledge. Jung himself, in Memories, Dreams, Reflections, acknowledged that the unconscious produces symbols he could not distinguish from religious ideas — imagery with a numinous character that resisted purely clinical interpretation.

Jung’s Scientific Legacy: What Has Lasted

Evaluating Jung’s legacy means separating what has proved robust from what has not. The clinical reality of complexes — emotionally charged unconscious configurations that shape behaviour beyond conscious control — is well established in modern psychotherapy.

His typology of introversion, extraversion, thinking, feeling, sensing, and intuiting gave rise to the Myers-Briggs Type Indicator, still among the world’s most widely used personality tools despite real psychometric limitations. The broader idea that personality has consistent structural dimensions is confirmed by the Big Five model, which overlaps significantly with Jungian types.

The concept of psychological projection — attributing to others qualities one denies in oneself — is a robust observation confirmed experimentally, even where the surrounding theory is contested. And the universality of mythological motifs across cultures, documented from Frazer and Lévi-Strauss to Joseph Campbell, is not seriously disputed.

What has held up less well: the specific archetypal figures, while clinically useful as descriptive categories, have not been validated as discrete universal structures. His later work on synchronicity and alchemy moved progressively further from testable claims. And the strong version of inherited content — that specific symbolic material is genetically encoded — faces the same problems as any claim about inheriting complex mental contents, which evolutionary biology finds implausible.

The honest assessment: Jung proposed a research programme more than a finished theory. He identified real phenomena — the universality of deep psychological patterns, the structured nature of the unconscious — that neuroscience is only now beginning to investigate with tools he never had.

One idea deserves particular note: individuation, Jung’s term for the lifelong process of becoming a whole, integrated self. He saw it as the central task of the second half of life — reconciling the conscious ego with the disowned material of the unconscious, including the Shadow.

Unlike some of his more speculative claims, individuation has aged well as a clinical framework. It maps closely onto modern ideas of psychological maturation, meaning-making, and post-traumatic growth, and remains a working concept in depth psychotherapy today.

Jung lived it as well as theorised it. He continued working, travelling, and writing into his eighties, dying at his home in Küsnacht on 6 June 1961. His final major work, Memories, Dreams, Reflections, was published the following year — part autobiography, part summary of a lifetime spent mapping the interior.

Why This Matters: Jung and the Science of Mind

Why Jung still matters is not primarily about whether his specific theories are correct. It is about what kind of science psychology should be, and which phenomena it should take seriously.

The dominant paradigms of the late twentieth century — behaviourism, cognitive science, neuroscience — were extraordinarily productive at explaining perception, attention, and memory. But they engaged far less with what occupied Jung most: the meaning of dreams, the experience of the numinous, the patterns that repeat across cultures and across a lifetime.

The recent convergence of psychedelic neuroscience with Jungian theory is not accidental. Research into psilocybin, LSD, and DMT at Imperial College London, Johns Hopkins, and NYU Langone reliably produces the experiences Jung described: encounters with archetypal figures, dissolution of ego boundaries, imagery that feels ancestral or transpersonal.

The neuroscience of these states — Predictive Processing, the Default Mode Network, entropic brain theory — may finally supply the mechanistic vocabulary for what Jung tried to describe in the language of his time.

His insistence that the scientist cannot be subtracted from the science — that a mind studying the mind is studying itself — has grown more relevant, not less. The hard problem of consciousness, which asks why subjective experience exists at all, is in part a Jungian problem. For where neuroscience stands on it, see our article on the hard problem of consciousness.

Jung spent his life on this problem. He did not solve it — but he described it with more precision and honesty than almost anyone before or since. That is why, more than sixty years after his death, the scientific conversation around his ideas is growing rather than fading.

Frequently Asked Questions

Sources

• McGovern, Aqil, Atasoy & Carhart-Harris — Eigenmodes of the Deep Unconscious, Neuroscience of Consciousness (2025)
• Review of Gary Clark, Carl Jung and the Evolutionary Sciences — International Journal of Jungian Studies (2025)
• Wikipedia — Collective Unconscious
• Wikipedia — Carl Jung
• Wikipedia — Synchronicity
• MacTutor — Carl Jung Biography (University of St Andrews)