You may, by force of will, bring about the first and second stages, concentration and meditation, but you cannot bring about the third stage, contemplation. All you can do is to prepare the prerequisite conditions for its coming . . . then, when it does come, it will seize you and swallow you. As it comes in, the strength of that which resists it, of the personal ego, begins to go out.
-- Notebooks Category 4: Elementary Meditation > Chapter 1: Preparatory > # 255