From Stoic Pneuma to Spiritus Mercurialis

The thread runs unbroken: the Stoic πνεῦμα — the active principle of the world, which pervades matter, the passive principle (Long & Sedley 1987) — is renamed spiritus mundi by the Latin alchemists, embodied in mercurius as spiritus mercurialis, spiritus vegetativus, spiritus seminalis (Jung 1967), and theorized by Jung as the alchemical refraction of the anima mundi. The substance is one; the names are many.

The Stoics gave it the cosmological argument: as ‘tenor’ breath makes it a unified object, as ‘physique’ it makes it an organism, as ‘soul’ it makes it an animate organism (Long & Sedley 1987). The alchemists gave it the operational vocabulary: a life-giving power like a glue, holding the world together and standing in the middle between body and spirit (Jung 1967). Plotinus mediated between them, structuring the descent and ascent of soul through νοῦς to the One (Plotinus, Enneads IV).

Jung made the inheritance explicit: the alchemists related their concept of the anima mundi on the one hand to the world soul in Plato’s Timaeus and on the other to the Holy Spirit, who was present at the Creation (Jung 1967). Ratio pneuma sits at the end of this thread — the Method’s name for the register in which the whole inheritance is reasoned with.

Sources

• plotinus: body passes; dissolution is in its very nature; all would disappear in a twinkling if all were body — soul-power as the sustaining principle (Enneads IV)
• Long & Sedley: the Stoic world-soul as divine breath coextensive with the grosser matter which forms the world’s body
• carl-jung: Mercurius as spiritus vegetativus, spiritus seminalis, spiritus mundi; the alchemical synthesis of Stoic, Platonic, and Christian pneumatology
• paracelsus: the iliaster as the moist, breathlike or vaporous soul dwelling in all bodies
• lyndy-abraham: the tria-prima doctrine that names mercury the spirit