Black bile was one of the four fundamental fluids in ancient and medieval medicine, and arguably the most philosophically troublesome of them. Its name — from the Greek melaina chole, dark or black gall — entered medicine as an explanation for why some people become gripped by persistent fear and sadness without obvious cause. Unlike blood or phlegm, which physicians could observe readily, black bile was in part a theoretical postulate: a substance needed to complete the symmetry of a four-part system tied to the four elements, the four seasons, and the four qualities of hot, cold, wet, and dry. For two thousand years, physicians debated what it actually was, where it lived in the body, and whether its pathological form was the same substance as its normal form or something produced by corruption. Those debates embedded in the very word melancholia — literally “black-bile condition” — a medical theory that outlasted its biology.
Origins in Hippocratic Medicine
The name derives from two Greek words: melan (black or dark) and chole (bile or gall).(Andrew Scull, 2015) That etymology is straightforward; the history of the concept is not. Vivian Nutton’s analysis of the Hippocratic corpus shows that the four-humour system as a tidy, symmetrical whole was far less universal in early Greek medicine than later tradition claimed. Two fluids — blood and phlegm — appear as genuinely important clinical categories across the corpus, but the other two, yellow bile and black bile, were less consistently present.(Nutton, 2023) In The Nature of Man, the foundational text for the four-humour doctrine, the author refers to black bile as “the so-called black bile” — a phrase that suggests the concept was still unfamiliar enough to require quotation marks, as it were, from the audience.(Nutton, 2023)
Nutton argues that the four-humour system as presented in The Nature of Man was a minority view even within the Corpus and was disputed by many later writers.(Nutton, 2023) Empedocles’ four-element theory, linking elements with qualities, had great explanatory potential, and theories of disease based on only three humours fell out of favour.(Nutton, 2023)
Whatever its contested origins, the humour acquired a clinical identity quickly. The core symptoms of what would be called melancholia were defined early: causeless sadness and causeless fear, persisting over time, without fever.(Lawlor, 2012) The symmetry of the four humours mapped onto a cosmological system that Lawlor traces in detail: blood corresponded to air and spring; yellow bile to fire and summer; black bile to earth and autumn; phlegm to water and winter.(Lawlor, 2012) Black bile governed the spleen and was associated with old age. The physician’s task was to identify which humour predominated and restore balance through diet, regimen, and evacuative treatments.
Aristotle’s Problema XXX.1
One of the most consequential texts in the history of melancholy is Problems 30.1, attributed to Aristotle (though likely a later Peripatetic compilation), which asked why it is that all men of outstanding achievement in philosophy, statecraft, poetry, or the arts appear to be melancholic.(Lawlor, 2012) The text linked this melancholic disposition to an excess of black bile.(Lawlor, 2012)
This claim did enormous cultural work. It associated melancholy not merely with disease but with genius, and it gave the humour an irreducible ambiguity: the same constitution that predisposed to depression predisposed to brilliance. Lawlor argues that this Aristotelian framing remained live in Western thought from antiquity through the Renaissance, and that it structured the way educated Europeans understood creative suffering as something inseparable from creative power.(Lawlor, 2012) The genius who suffers was not simply ill; they were in excess of ordinary humoral balance.
Rufus of Ephesus and the Two-Substance Theory
The most sophisticated ancient account of melancholy came from Rufus of Ephesus, a physician of the first or second century CE whose work on melancholy was by common acclaim the best ever written on the subject, though it was lost.(Pormann, Peter E. (ed.), 2008) Pormann’s edition and analysis of the surviving fragments shows that Rufus is frequently overlooked in standard histories, which tend to emphasize Hippocrates, Aristotle, and Galen while neglecting Rufus, despite his central importance to the tradition.(Pormann, Peter E. (ed.), 2008) Pormann identifies Rufus as unique among ancient physicians in combining two traditions in a single account: melancholy as a physiological mental disease, and melancholy as a constitutional disposition leading both to despair and to extraordinary creativity, thereby setting the tone for subsequent developments in both strands.(Pormann, Peter E. (ed.), 2008) His three most enduring contributions were: reviving the link between melancholy and intellectual effort, introducing the two-substance theory of black and yellow bile (the foundation of the later melancholia adusta tradition), and shaping the understanding of hypochondriac melancholy.(Pormann, Peter E. (ed.), 2008)
Rufus also drew explicitly on the Peripatetic tradition to characterize the innate melancholic type: he connected characteristics from Problem 30.1 — excessive mental activity predisposing to melancholy, a craving for sexual intercourse, an affinity for wine, and a tendency toward prophetic ability — to the broader humoral account of the melancholic temperament.(Pormann, Peter E. (ed.), 2008) Rufus distinguished two types of black bile: natural black bile that is harmless when settled, and black bile produced by burning or cooling of yellow bile.(Pormann, Peter E. (ed.), 2008) The burnt product causes violent behaviour, while the cooled product causes depression.(Pormann, Peter E. (ed.), 2008) Pormann identifies this two‑substance theory as Rufus’s original contribution to the tradition,(Pormann, Peter E. (ed.), 2008) noting that Rufus placed his own stamp on the traditional link between melancholy and intellectual work.(Pormann, Peter E. (ed.), 2008)
Rufus also linked melancholy to what we might now call occupational burnout. He described the condition that Pormann calls the “decompensation of the overworked scholar” — a pattern in which excessive intellectual labor depleted the vital heat, produced abnormal concentrations of black bile, and resulted in the characteristic triad of fear, despondency, and disordered thought.(Pormann, Peter E. (ed.), 2008) This scholar’s melancholy would later be taken up by Robert Burton, who cited Rufus at length in the Anatomy of Melancholy when cataloguing the particular miseries of intellectual life.(Pormann, Peter E. (ed.), 2008) Rufus also catalogued specific delusional content that became diagnostic touchstones: some patients believed their body had been transformed into earthen vessels; others thought their skin had become parchment; others believed they had lost their head.(Pormann, Peter E. (ed.), 2008)
The range of causes Rufus recognized was also broader than purely humoral. He included among the causes of melancholy excessive thinking, grief, and psychological trauma — recognizing that the mind could disturb the body’s humoral balance through its own activity.(Pormann, Peter E. (ed.), 2008) This was not a departure from humoral theory but an expansion of its causal reach: mental events were real events with physical consequences.
Galen’s Systematization
Galen of Pergamon, writing in the second century CE, absorbed and systematized Rufus’s work and made black bile central to his comprehensive physiology. Galen wrote a dedicated treatise, On Black Bile, in which he explicitly praised Rufus as the authoritative prior voice.(Pormann, Peter E. (ed.), 2008) The tripartite division of melancholia that became standard — whole-body melancholy, brain-originating melancholy, and hypochondriac melancholy (originating in the upper abdomen) — was derived by Galen directly from Rufus’s earlier taxonomy.(Pormann, Peter E. (ed.), 2008)
Galen’s metaphor for melancholic disturbance was spatial: an excess of black bile in the blood reached the brain and cast a kind of darkness over the seat of thought, as if a lamp had been placed in a smoke-filled room.(Lawlor, 2012) He described three subtypes of the condition: those who were afraid and despairing; those who were laughing and cheerful despite their underlying derangement; and those who were primarily disordered in their thoughts about specific topics while reasoning normally about everything else.(Lawlor, 2012) This clinical differentiation, grounded in humoral excess, remained the dominant taxonomy of depressive and psychotic conditions in European medicine for more than a thousand years.
Islamic Reception and the Hospital Tradition
By the ninth century, Rufus’s work on melancholy had been translated into Arabic, entering the Islamic medical tradition alongside Galen.(Pormann, Peter E. (ed.), 2008) Isḥāq ibn Imrān, a ninth-century physician working in Kairouan (in present-day Tunisia), produced an Arabic monograph on melancholy.(Pormann, Peter E. (ed.), 2008) He analyzed its causes as a mixture of the biological, the psychological, and the situational: excessive study, grief, prolonged illness, passionate love, anger, and fear could all disturb humoral balance and produce the melancholic condition.(Pormann, Peter E. (ed.), 2008) Isḥāq’s fate was grim: he was eventually executed by the sultan who had employed him, after a dispute.(Pormann, Peter E. (ed.), 2008)
Constantine the African (d. before 1099), an eleventh-century monk at Monte Cassino who translated Arabic medical texts into Latin, produced a Latin version of Isḥāq ibn Imrān’s On Melancholy under his own name, stripping the attribution.(Pormann, Peter E. (ed.), 2008) The independent end of his treatise contains Latin fragments derived directly from Rufus’s Arabic version.(Pormann, Peter E. (ed.), 2008)
Pormann writes that Baghdad in the 9th–10th centuries was the major centre for translation of Greek texts including Rufus’s On Melancholy into Arabic, and developed the first secular hospitals open to all classes that became central to providing mental health care.(Pormann, Peter E. (ed.), 2008) Al-Kaskarī, working in a hospital, employed Greek recipes but refined and tested them through his own experience treating melancholic delusion.(Pormann, Peter E. (ed.), 2008)
Maimonides, the twelfth-century physician and philosopher who served the Ayyubid court in Cairo, treated the prince al-Afḍal for a condition that reads in the sources as melancholic in character — presenting with despondency, withdrawal, and disturbed thinking.(Pormann, Peter E. (ed.), 2008) His treatment was integrative, combining dietary regulation, exercise, social engagement, and careful attention to the patient’s psychological state alongside humoral interventions.
Medieval Elaboration
The medieval European reception of black bile introduced a theological dimension that the ancient sources had not contained. Hildegard of Bingen, the twelfth-century Benedictine abbess and natural philosopher, mapped black bile onto the doctrine of original sin: she argued that the emergence of the melancholic humor in its pathological form was a direct consequence of Adam’s fall.(Pormann, Peter E. (ed.), 2008) Before the transgression, Hildegard held, the four humors had been perfectly balanced; sin introduced the excess and corruption that produces disease. This was not simply allegory: for Hildegard, the physical reality of black bile and the theological reality of sin were causally connected. Melancholy was simultaneously a medical condition and a mark of humanity’s fallen state.
Renaissance Glorification
By the Renaissance, two competing traditions had formed around melancholy: the Galenic tradition treating it as a serious physical illness, and the Aristotelian/Ficinian tradition celebrating it as a vehicle for creative genius.(Lawlor, 2012) These traditions coexisted, “hopelessly entangled”, in literary culture.(Lawlor, 2012)
Marsilio Ficino, the fifteenth-century Florentine philosopher who translated Plato into Latin and whose De Vita became one of the most widely read medical-philosophical texts of the Renaissance, pursued both traditions simultaneously. He was himself a declared melancholic, and he developed an elaborate account in which the planet Saturn governed the melancholic temperament.(Lawlor, 2012) Saturn, the outermost and coldest planet, corresponded to the cold-dry quality of black bile; scholars and philosophers, who engaged in the most abstract and solitary intellectual labor, were particularly under its influence. This astrological framework gave melancholy a cosmic dignity that exceeded anything in Galen.
The association between melancholy and alchemy reinforced these themes in another direction. The alchemical stage called nigredo — the blackening that preceded the transformation of base matter into gold — was read as the symbolic equivalent of the melancholic state: the soul’s descent into darkness as a precondition for eventual illumination.(Lawlor, 2012) Melancholy, in this register, was not merely a disease or a constitutional type but a stage in a spiritual and cognitive process.
This association made the melancholic fashionable among the educated classes of Tudor and Stuart England. Lawlor traces how melancholy became, paradoxically, a marker of social distinction in the late sixteenth and early seventeenth centuries — something to be cultivated, performed, and displayed as evidence of intellectual depth.(Andrew Scull, 2015) Robert Burton’s Anatomy of Melancholy (1621), the most comprehensive English-language treatment of the subject, was written by a professed melancholic and catalogued the condition’s causes, symptoms, and cures with encyclopedic thoroughness, drawing liberally on Rufus, Galen, the Arabic tradition, and every other source Burton could find.(Andrew Scull, 2015)
The Dissolution of Black Bile
Thomas Willis, following the iatrochemical school, broke with humoral theory in his Two Discourses Concerning the Soul of Brutes (1672).(Lawlor, 2012) He denied that melancholy arose from a melancholic humour and attributed it instead to obscured and thickened animal spirits.(Lawlor, 2012)
By the time of Queen Anne — the early eighteenth century — the vocabulary of melancholy had already begun to give way to new terms. The spleen, hysteria, and the vapours replaced black bile as the fashionable explanatory categories for the emotional and nervous complaints of the educated classes in England.(Lawlor, 2012) These terms retained some functional overlap with the older humoral concepts — the spleen had long been understood as the organ where black bile was stored or processed — but they no longer implied the full cosmological apparatus of the four humours. William Cullen’s later-eighteenth-century taxonomy of nervous disease, which organized mental and emotional complaints under the heading of neuroses (disorders of the nervous system), completed the displacement of humoral theory from the center of psychiatric explanation.(Lawlor, 2012)
Persistence in Unani Medicine
While European medicine abandoned humoral theory over the course of the seventeenth and eighteenth centuries, the tradition survived and continued to develop within Unani (Islamic-Greek) medicine, which remained the dominant medical system across large parts of the Middle East, South Asia, and North Africa into the modern period. In the Unani framework, as Chishti’s handbook makes clear, black bile functions as the terminal stage of dietary and metabolic imbalance: a patient who persistently consumes cold and heavy foods progresses through imbalances in phlegm and yellow bile before arriving finally at black bile excess, at which point the conditions associated with cancer and arteriosclerosis may emerge.(Chishti, 1988) Dark urine in Unani diagnosis indicates either the evacuation of black bile in a healing crisis or an extreme of internal cold.(Chishti, 1988)
This is not nostalgia or anachronism within the Unani tradition: it is a working clinical system with its own internal logic, its own pharmacopoeia, and its own practitioners. The persistence of black bile as a diagnostic and therapeutic category in Unani medicine is a reminder that the humoral framework was not merely superseded — it continued to function in contexts where its clinical tools had proved useful. Western herbal practice retained this therapeutic logic as well: the Salernitan herbal prescribed fumitory (Fumaria officinalis) as a remedy that “purges especially the melancholic humour,” a use still catalogued in early modern texts as melancholi fuga — flight of melancholy.(Tobyn Denham Whitelegg, 2011)
The Question of Physical Existence
Did black bile exist as a physical substance? The ancient physicians debated this, though not always in those terms. Nutton’s analysis of the Hippocratic corpus shows that black bile was partly a theoretical construct from the beginning — present in the nosological scheme not primarily because physicians had isolated it in the body but because the fourfold symmetry of the system required it.(Nutton, 2023) Rufus’s two-substance theory complicated the question further: if one kind of black bile is produced by burning other humours, and if this burnt product is the more clinically important one, then the “original” black bile is something of an abstraction that becomes physiologically real only through pathological transformation.
Some historians have suggested that the dark, tarry material produced by digestion of blood — oxidized hemoglobin products — may have been what ancient physicians were observing when they described black bile in stools and vomit. Others argue that the four humors were always primarily theoretical categories rather than identifiable biological substances, and that asking whether black bile “really existed” is a category error — like asking whether the equinoxes “really exist” as physical objects.
What is not in doubt is the explanatory work black bile performed. It gave medical practitioners across two millennia a vocabulary for the most baffling class of human suffering: the person whose body shows no wound, no fever, no visible disease, but who has become immobilized by fear, evacuated of joy, and convinced of their own ruin. The humoral account of that experience was not merely a historical curiosity. It organized clinical practice, shaped treatment, generated substantial theoretical debate, and embedded itself in the cultural vocabulary — melancholy, sanguine, choleric, phlegmatic — that English still uses to describe personality and mood.