The long climb toward the source.
An old science of the soul, kept honest by the body.
Spirit is the climb, the long ascent toward the source, the part of the work that rises where the others descend. We keep it roped to the body the whole way, so that whatever you touch up there comes back down through how you earn and love and hold power, and never drifts off into the bliss and fantasy that swallows so much of this work.
It is a discipline, exact and demanding, with methods that work and results you can stand behind. Over years of patient practice it builds two things in you: an instrument fine enough to perceive the inner worlds as they actually are, and a bridge, raised span by span, between the person you have been and the part of you that was never born and does not die. The other three streams carry you down into matter and in toward the wound. This one builds the eyes to see by, and the bridge to cross on.
None of this is knowledge for its own sake. The teaching itself says so, that the training of the mind is the doorway and never the destination, and that the one it is really addressing is the soul, the dweller in the mind, the director of the whole experience. Every piece of it is pointed at one thing, meeting the crossings of initiation awake and walking through them on your own feet.