The Three Vital Airs.

It is the pure Âkâsha that passes up Sushumnâ: its two aspects flow in Idâ and Pingalâ. These are the three vital airs, and are symbolized by the Brâhmanical thread. They are ruled by the Will. Will and Desire are the higher and lower aspects of one and the same thing. Hence the importance of the purity of the canals; for if they soil the vital airs energized by the Will, Black Magic results. This is why all sexual intercourse is forbidden in practical Occultism.

From Sushumnâ, Idâ and Pingalâ a circulation is set up, and from the central canal passes into the whole body. (Man is a tree; he has in him the macrocosm and the microcosm. Hence the trees used as symbols; the Dhyân-Chohanic body is thus figured.)