Their objective is to see clearly through all events, through space and time by means of the cultivation and use of the intuition. They work very largely on the astral plane at the dissipation of glamour, thus bringing in illumination to mankind. Thus another type of energy is brought into play, producing another type of inter-relation and communication. This communication is between the plane which is the plane of illumination and pure reason (the buddhic plane) and the plane of illusion and glamour, which is the astral plane. The Trained Observers are asked to remember that their great task is to dispel the world illusion through the pouring in of light.
(Discipleship, I, p.35-40)