The grand illumination itself is sudden but the process of achieving it is a task so complex that it can be carried through only by successive stages. For the obstructions to be cleared on the way are heavy and numerous while the advances involve shifting from one tentative standpoint to another. The way to ultimate being cannot be travelled in a single leap; there must be a time-lag until the moment when it actually dawns. The interval naturally falls into elementary, intermediate, and advanced stages. Nothing once gained in yoga need be discarded; only we take it up into the wider gain which absorbs and preserves but also transcends it. The newer knowledge does not disqualify the results of earlier investigations. For the price of advanced yoga must be paid partly out of the profits got from elementary yoga. For want of a better term, we have sometimes designated the highly advanced meditation exercises here given as "ultramystic"--for a study of them will reveal that the common or popular forms of yoga do not exhaust the possibilities of man's quest of the Overself.
-- Notebooks Category 23: Advanced Contemplation > Chapter 6: Advanced Meditation > # 20