The Black Sun — sol niger in the Latin alchemical tradition, soleil noir in French Romantic poetry — occupies a precise and consequential position in the depth-psychological corpus. Jung anchors the term firmly in the alchemical nigredo, identifying the sol niger as the darkened solar principle that emerges when the gold of consciousness undergoes mortification and putrefaction in the vessel. His 1942 correspondence with Schmied is the documentary locus classicus, tracing the image across Pythagorean counter-earth speculation, Baudelaire, Nerval, and operative alchemy, insisting it is not a marginal curiosity but a recurring archetypal necessity. In Alchemical Studies, Jung interprets a patient's mandala in which 'the black sun' figures as the integrated shadow located at the solar plexus, the dark principle made interior. Von Franz extends this reading through the Sol niger's identity with Saturn — the devouring shadow-aspect of the Self — and connects it to the unjust, one-rayed sun that drives inflation and destruction. Thomas Moore's clinical vignettes ground the symbol experientially, showing how the black sun appears in depression as an image simultaneously of devastation and latent gold. The tension between these readings — pathological eclipse versus initiatory darkness, Saturnine devouring versus alchemical prelude — constitutes the central problematic the corpus holds open.
With regard to your question about the black sun, Baudelaire's 'soleil noir' is by no means an exception. The idea of a counter earth occurs, for instance, in the Pythagorean system, and we find the sol niger in alchemy, also the ignis niger.
Jung's definitive documentary statement on the Black Sun, situating the sol niger within a cross-cultural lineage spanning Pythagorean cosmology, Romantic poetry, and operative alchemy.
, Letters Volume 1: 1906-1950, 1973thesis
With regard to your question about the black sun, Baudelaire's 'soleil noir' is by no means an exception. The idea of a counter earth occurs, for instance, in the Pythagorean system, and we find the sol niger in alchemy, also the ignis niger.
A verbatim parallel of Jung's canonical letter on the Black Sun, confirming the text's significance across both volumes of the correspondence.
, Letters Volume 2, 1951-1961, 1975thesis
The black earth that was previously far below her feet is now in her body as a black ball, in the region of the manipūra-chakra, which coincides with the solar plexus. (The alchemical parallel to this is the 'black sun.') This means that the dark principle, or shadow, has been integrated.
Jung explicitly glosses a patient's mandala image through the alchemical black sun, interpreting it as the successful integration of the shadow into the body's centre of gravity.
, Alchemical Studies, 1967thesis
Saturn as Sol niger, shadow of the sun (or dark side of God) devouring his children. 'When the Self is not supported it sends a neurosis, i.e., the shadow of the Self comes into action and God and nature become enemies to man.'
Von Franz identifies the Sol niger with Saturn as the devouring shadow-aspect of the Self, framing the Black Sun as the mythological image of unmediated divine darkness turned against the human.
, Alchemy: An Introduction to the Symbolism and the Psychology, 1980thesis
If a highly focussed consciousness is driven, then one has a dark sun. People use consciousness to convince you that they are right in doing the wrong thing.
Von Franz extends the Sol niger into a clinical register, equating the dark sun with the pathological inflation of one-sided, self-justifying consciousness.
, Alchemy: An Introduction to the Symbolism and the Psychology, 1980supporting
For her this black sun appeared after a long siege of depression, an image of her darkness but with a promising indication of the gold that lay within the black mass of melancholy.
Moore presents a clinical dream image of the black sun as a phenomenological encounter with Saturnine depression that simultaneously harbours the promise of the gold concealed within the nigredo.
, The Planets Within: The Astrological Psychology of Marsilio Ficino, 1990supporting
For her this black sun appeared after a long siege of depression, an image of her darkness but with a promising indication of the gold that lay within the black mass of melancholy.
The earlier edition of Moore's Ficino study presents the same clinical vignette, confirming its centrality to his account of Saturnine depression and the Black Sun's dual valence.
, The Planets Within: The Astrological Psychology of Marsilio Ficino, 1982supporting
black/blackening, 126n, 169, 229f, 271, 390n 'black blacker than black,' 327 ... sun, 110, fig. 34
The index of Psychology and Alchemy maps the black sun as a discrete pictorial and conceptual node within Jung's comprehensive treatment of the nigredo sequence, cross-referenced to its visual representation.
, Psychology and Alchemy, 1944supporting
In the deepest reach of the stream shines a red sun, radiating through the dark water. There I see—and a terror seizes me—small serpents on the dark rock walls, striving toward the depths, where the sun shines.
In the Red Book's underworld descent, Jung encounters a luminous sun shining through dark water — an imaginal precursor to the sol niger motif, here presented as a terrifying subterranean solar presence.
, The Red Book: Liber Novus, 2009supporting
At this point of blackness and death it is as if the sun has been eclipsed forever and the adept may experience the deep despair associated with the black night of the soul (see eclipse, melancholia, sun and shadow).
Abraham's dictionary locates the sol niger within the nigredo's lexical field, connecting the eclipsed sun directly to the alchemical experience of irreversible darkness and the melancholia of the opus.
, A Dictionary of Alchemical Imagery, 1998supporting
Michael Maier used the dramatic image of throwing 'snow in Saturn's black face' in order to represent the process of whitening the blackened 'body' of the Stone, which has putrefied in the bottom of the vessel at the nigredo.
Abraham documents Maier's emblem of Saturn's black face as a visual cognate of the sol niger, situating the Black Sun within the Saturnine, putrefactive phase of the opus alchymicum.
, A Dictionary of Alchemical Imagery, 1998supporting
the red sun standing out on a black background... this red sun and these reddening orbs announce the presence of the Angel-Logos... angelophany is associated with the symbol of the 'midnight sun,' of luminous Night.
Corbin's Iranian Sufi material offers a parallel tradition — the midnight sun or black-backgrounded solar vision — that approaches the Black Sun from the direction of mystical angelology rather than alchemical pathology.
, The Man of Light in Iranian Sufism, 1971aside
In the second tablet there are two suns: one emits two rays onto the lower world, and the other only one. Both radiate to the lower world.
Von Franz's Arabic alchemy material on the doubled sun — one just, one unjust — provides the conceptual backdrop for the dark or single-rayed sun that collapses into the sol niger when consciousness operates one-sidedly.
, Alchemy: An Introduction to the Symbolism and the Psychology, 1980aside