Pneuma

The active, divine fire-breath principle that permeates matter, ordering and animating all things.

Pneuma (πνεῦμα) is, in Stoic physics, the active principle of the universe: a fine, fiery breath-substance identical with the Logos (divine reason). It permeates all matter (Hyle) and thereby generates all structure, life, and order. Pneuma is not immaterial; rather, it is an extremely subtle, quasi-gaseous form of matter. It is simultaneously the soul of all things and the intelligent force that sustains the universe as a harmonious organism.