Explanation of diagram: The deeper he looks into his own nature--a procedure which cannot be done without practising meditation--the nearer he will come to the truth about it.
In the first stage of penetration, his external surroundings, and the whole world with them, vanish. In the second and deeper stage, the feeling "I am rooted in God" alone remains. In the third stage the "I" thought also goes. In the final stage even the idea"God" disappears. There remains then no idea of any kind--only peace beyond telling, consciousness in its pure ever-still state.
If he stops at levels A or B, he is still unable to fulfil his purpose. It is just as if a composer of a piece of music were to stop halfway during its composition. Only by penetrating still farther into the depths of his being until he reaches level C will he be able to undergo that tremendous, profound, and radical change which may be called the first degree of illumination. So sudden and so startling a change could not have come unless he had had the perseverance to make so prolonged a plunge.
Few mystics pass the first degree. The rapture of it detains them.
-- Notebooks Category 23: Advanced Contemplation > Chapter 7: Contemplative Stillness > # 60