Within the depth-psychology corpus, 'liquid' operates as a foundational ontological and psycho-physiological category rather than a merely material descriptor. The term clusters around two broad axes. The first, most systematically developed by R. B. Onians, concerns the archaic Greek and Roman identification of liquid with life itself: the cerebro-spinal fluid, seed, sweat, tears, and marrow collectively constitute the αἰών, the 'life-liquid' whose diminution marks aging and whose exhaustion marks death. Dryness signals mortality; wetness signals vitality. Homer's very word for 'alive' (διερός) means 'moist.' The second axis traverses alchemical psychology, where liquid functions as the prima materia in its most active, dissolving state — aqua mercurialis, the philosophical water that simultaneously destroys and recreates form. Von Franz, Abraham, and Jung all document alchemy's insistence that transformation requires first a liquefaction of solid matter, a solve before coagula. Plato's Timaeus contributes a cosmological dimension, distinguishing liquid from fusile water by the irregularity of its particles, thus linking fluidity to formlessness and potentiality. Ruth Padel traces the medical-poetic inheritance of these ideas into Greek tragedy, where inner flux of humors both causes and expresses emotional states. The central tension across these traditions is between liquid as generative substance and liquid as dangerous excess — the boundary between vivifying moisture and pathological flood.
In the library
20 passages
there is in us our own liquid (or "moisture", οἰκείαν... ὑγρότητα) according to which we are sensible and by which we live; when this liquid is in its proper condition, the living creature is healthy, but when it is dried up, the living creature lacks sense and dies
Onians, citing Hippo, demonstrates that ancient physiology identified a specific internal liquid with consciousness and life itself, such that desiccation of that liquid constitutes both cognitive failure and death.
Onians, R B, The origins of European thought about the body, the mind,, 1988thesis
normally the liquid diminishes with the passing of life so as to seem in a sense its measure... the dead were for the Greeks pre-eminently 'dry'. It fits our finding that αἰών, the 'life', was the 'liquid', that Homer expresses 'living, alive' by 'moist, wet', διερός.
Onians establishes the structural equation liquid = life in Homeric thought, where the measurable diminution of the life-fluid provides the experiential basis for understanding mortality as progressive desiccation.
Onians, R B, The origins of European thought about the body, the mind,, 1988thesis
The earlier evidence implied that this liquid in the flesh was one with the cerebro-spinal fluid and the seed, the stuff of life and strength... Sexual love is repeatedly described as a process of 'liquefying, melting' (τήκεσθαι) and is characterised as ὑγρός, 'liquid, wet'.
Onians traces the identity of the life-liquid across multiple bodily substances — cerebro-spinal fluid, seed, sweat, tears — and shows that eros itself was understood as a liquefying process governed by the same substance.
Onians, R B, The origins of European thought about the body, the mind,, 1988thesis
The earth becomes liquid and is transformed into water, water becomes liquid and is transformed into air, air becomes liquid and is transformed into fire, fire becomes liquid and is transformed into glorified earth.
Von Franz cites an alchemical text in which liquefaction is the universal mechanism of elemental transformation, each element becoming liquid as the precondition for ascending to the next stage of the opus.
von Franz, Marie-Louise, Alchemy: An Introduction to the Symbolism and the Psychology, 1980thesis
The dry seed needs moisture anew if it is to begin life anew. So the dry bones, it might be hoped, receiving life-liquid, might live.
Onians interprets the Homeric ritual of preserving heroes' bones in fat and wine as a practical application of the belief that reinfusion of life-liquid into desiccated remains could restore or perpetuate vitality.
Onians, R B, The origins of European thought about the body, the mind,, 1988thesis
The liquid kind is composed of the small and unequal particles of water; and moves itself and is moved by other bodies owing to the want of uniformity and the shape of its particles.
Plato's Timaeus grounds the property of liquidity in the micro-structural irregularity of water particles, providing a cosmological physics of fluidity that links formlessness to motility and transformability.
the Homeric Greeks appear to have believed that in the generative 'fluid' (αἰών) was the gaseous ψυχή, Thales held that the elemental liquid and its developments were permeated by ψυχή.
Onians traces the transition from archaic physiological belief to early Greek philosophy, showing that Thales' identification of water as the elemental principle extended the Homeric equation of liquid with soul-bearing life.
Onians, R B, The origins of European thought about the body, the mind,, 1988supporting
Any flood, dripping, or swelling should force unwanted liquid out... Inner 'waves' must flow out. If the extra liquid does not drain away, it must be made to go.
Padel documents Greek medical and poetic assumptions that pathological states involve excess liquid that must be purged, establishing a hydraulic model of inner life in which health requires the proper circulation and drainage of fluid.
Padel, Ruth, In and Out of the Mind Greek Images of the Tragic Self, 1994supporting
Wine was in a peculiar degree equated to, identified with the life-fluid, and not less in Italy than in Greece. The Romans believed in a diminishing 'sap' (sucus) or liquid of life in the body as in a plant.
Onians demonstrates that wine served as the culturally paradigmatic substitute for the body's own life-liquid, the equation of vita vinum est expressing a systematic identification of vegetable sap, bodily sucus, and vitality.
Onians, R B, The origins of European thought about the body, the mind,, 1988supporting
the mind at the same time has lost its calm and rational state and is possessed by liquid... both Greeks and Romans believed that the mind in the lungs was in direct relation to the native liquid there, the blood, and that water or wine, alien liquid, when drunk, went to the lungs, and the power in it possessed or displaced the mind there.
Onians shows that mental disturbance (lymphatus) was understood as the intrusion of a foreign liquid into the organ of mind, making liquid the physical vehicle of both rational and irrational psychic states.
Onians, R B, The origins of European thought about the body, the mind,, 1988supporting
the water from which everything originates and in which everything is contained, which rules everything, in which errors are made and in which the error is itself corrected. I call it 'philosophical' water, not ordinary vulgi water but aqua mercurialis.
Jung cites the alchemical aqua mercurialis as an all-encompassing liquid principle that is simultaneously origin, medium, and corrective agent — a psychological symbol of the unconscious itself as prima materia.
Jung, Carl Gustav, Psychology and Alchemy, 1944supporting
pouring wine or other liquid for the benefit of someone living... It is a gift of the liquid of life as in the surviving practice of the Cyclades.
Onians interprets libation and ritual pouring as applications of the belief that liquid conveys life-force, the act of pouring wine being a direct transfer of vitality to the recipient.
Onians, R B, The origins of European thought about the body, the mind,, 1988supporting
pain happens when liquid and breath enter the same inner parts... 'When the fluid blood rushes away, the bubbling air rushes in.... When the blood leaps up, the air is breathed out again.'
Padel documents Empedocles' model in which liquid and pneuma alternately occupy the same bodily channels, making the flow of liquid the physiological counterpart of breath and the mechanism of sensation.
Padel, Ruth, In and Out of the Mind Greek Images of the Tragic Self, 1994supporting
It fits the original sense of fluid for αἰών that unlike ψυχή and θυμός it is not said to leave the body in a swoon or go to Hades. It flows away in tears.
Onians precisely distinguishes the life-liquid (αἰών) from the soul (ψυχή) and spirit (θυμός) by its mode of departure — not as an escaping entity but as flowing out through tears, confirming its fundamentally liquid nature.
Onians, R B, The origins of European thought about the body, the mind,, 1988supporting
libare melle, vino... 'to make by means of wine, honey, a libation which consists in pouring out the liquid drop by drop.' ... the basic sense is 'steeped in a liquid which drips.'
Benveniste recovers the Indo-European linguistic ground of libation as ritual dripping, establishing that the sacred use of liquid in offering derives from a primary sense of controlled, minimal effusion of a precious fluid.
Benveniste, Émile, Indo European Language and Society, 1973supporting
the sucus, the liquid of life and strength in the body, was recognised in sweat... the fat... Pliny: pingue inter carnem cutemque suco liquidum.
Onians traces the Roman concept of sucus as the bodily liquid of vitality, recognizable in sweat, fat, and marrow, confirming the pan-Mediterranean identification of an internal moist substance with strength and life.
Onians, R B, The origins of European thought about the body, the mind,, 1988supporting
Giegerich's index entries for liquefaction and liquidity, cross-referenced with fluidity across multiple pages, indicate that these concepts function as a sustained philosophical-psychological theme throughout his argument about soul and logical negativity.
Giegerich, Wolfgang, The Soul’s Logical Life Towards a Rigorous Notion of, 2020aside
'Is his memory so wet?' Here should also be considered... 'Before the heart in sleep there drips (στάζει) pain woe-recalling'.
Onians assembles evidence that wetness of memory and the dripping of pain before the heart are ancient Greek expressions of the liquid basis of psychic processes, where moisture connotes cognitive and emotional excess or impairment.
Onians, R B, The origins of European thought about the body, the mind,, 1988aside
rather than speak of menos as a liquid that 'once' meant blood, or that by the time Homer uses it is only an abstract force, I would follow its diversity. In many places it behaves like blood, resonant with anger's blood connotations.
Padel argues for the irreducible dual nature of menos as simultaneously liquid-physical and emotional-abstract, resisting any developmental narrative that would strip the term of its material, liquid resonances.
Padel, Ruth, In and Out of the Mind Greek Images of the Tragic Self, 1994aside
the supercooled liquid can pass to the crystalline state, and this passage depends on two factors: the power of spontaneous crystallization that this liquid presents... and, on the other hand
Simondon uses the physics of a supercooled liquid at the threshold of crystallization as a model for metastable states of individuation, where liquid represents pre-individual potentiality not yet resolved into stable form.
Simondon, Gilbert, Individuation in Light of Notions of Form and Information, 2020aside