PNEUMA

Ancient Greek thought early posited a connection between breath and life. The notion that wind or breath—pneuma —accounted for the functions of living things persisted in philosophical and medical accounts of organisms, sometimes alongside the notion of an immaterial soul or psychē. The idea that a distinct kind of pneuma played a role in the functioning of organisms seems to have developed in early medical theory. Some texts refer to pneuma as a kind of nutriment. The idea that there is a specifically "psychic" pneuma is found in the doctor Diocles of Carystus (fourth century BCE), who had connections to Aristotle's school.

In Aristotle's biology an innate pneuma is mentioned in connection with a number of functions of the organism and is even compared to the ether, the fifth element from which the heavenly bodies are composed. In the case of sexual generation pneuma is used to explain the ability of the male seed to convey its movements to the female matter without contributing matter to the resulting embryo; in animal movement it helps explain the movement of the limbs. There is room for doubt about how systematically Aristotle used the concept, however, or its relationship to the elements. His second successor, Strato of Lampsacus, seems to have considered pneuma to be the material substance of the soul, perhaps in recognition of the discoveries of Hellenistic medicine; a treatise on pneuma survives in the Aristotelian corpus.

Praxagoras (fourth century BCE), who distinguished veins from arteries, theorized that the latter contain only pneuma ; this was eventually rejected by Galen. The Hellenistic doctors Herophilus (c. 335–c. 280 BCE) and Erasistratus (flourished c. 250 BCE) recognized a system of neura or nerves originating from the brain, responsible for motor and perceptual functions. Because some nerves were seen to be hollow, they were thought to contain a special kind of pneuma suited to their functions. In Galen's physiology the "vital pneuma " is distributed through the arteries; the brain refines this into "psychic pneuma," which, through the nerves, is the instrument by which the soul performs its functions.

Unlike these medical theories associating pneuma with the vascular systems, Epicurus describes the material soul as like, or partly composed of, pneuma. In Stoic philosophy it played a broader role. The Stoics hypothesized that pneuma —for them, a kind of hot air—is distributed throughout all other matter in the cosmos. Supposing that all action happens by bodies in contact, yet needing to account for apparent cases of action at a distance, the Stoics held that the pervasiveness of this single material accounted for the "sympathy" between distant bodies, as well as the cohesiveness of the cosmos as a whole and the qualities of individual things. Associated with the divine intelligence pervading the cosmos, the part of the cosmic pneuma pervading living things is the soul.

The Greek term pneuma was later used in religious contexts and associated with spirit and the divine. The physiological use of pneuma to account for functions of living things is echoed in the early modern notion of "animal spirits."

See also Aristotle; Epicurus; Stoicism; Strato and Stratonism.

Bibliography

Freudenthal, Gad. Aristotle's Theory of Material Substance: Heat and Pneuma, Form and Soul. Oxford, U.K.: Clarendon Press, 1995.

Solmsen, Friedrich. "Greek Philosophy and the Discovery of the Nerves." In Kleine Schriften. Vol. 1, 536–582. Hildesheim, Germany: Georg Olms Verlagsbuchhandlung, 1968.

Staden, Heinrich von. "Body, Soul, and Nerves: Epicurus, Herophilus, Erasistratus, the Stoics, and Galen." In Psyche and Soma: Physicians and Metaphysicians on the Mind-Body Problem from Antiquity to Enlightenment, edited by John P. Wright and Paul Potter, 79–116. Oxford, U.K.: Clarendon Press, 2000.

Sylvia Berryman (2005)