This wisdom is generally divided into two parallel, equal, and identical orders, like two drops in a pond. The only difference between them is that the first order extends from above downward, to this world, and the second order begins in this world and traverses from below upward precisely by the same routes and make-ups imprinted at their root when they appeared from above downward.
Baal HaSulam, The Essence of the Wisdom of Kabbalah

