Pneuma

Pneuma, ‘spirit’, derives from the Greek verb pneo, which indicates blowing or breathing. Since breathing is necessary for life and consciousness, pneuma came to denote not only wind and breath but various vital functions, including sensation and thought, and was understood by some philosophers as a cosmological principle. It became especially important in Stoicism, which explained the world in terms of matter and the rational structure exhibited in all its forms; this is established by rhythmical variations in the tonos or ‘tension’ of the pneuma.

In Hebrew tradition, where Greek was used, pneuma stood for life, consciousness, and for invisible conscious agents, angels or demons. In Christian thought it denotes divine inspiration, in particular the Holy Spirit acknowledged as a divine Person. At John 4:24 it is used, unusually, to describe God himself.