Pneuma

Pneuma — 'breath' or 'spirit' — names the vital air that animates living things, and in the hands of the philosophers it became a cosmic principle. For the Stoics it was the warm, fiery breath that pervades all things and holds the cosmos together in sympathy, constituting the world-soul and, in us, the soul itself; the tension of pneuma gives each thing its cohesion and quality.

For the Platonists, pneuma was the stuff of the soul's astral vehicle, the subtle body midway between matter and spirit. The word, passing into religious use, became the 'spirit' of later theology — the breath of the divine within the world.