This Principle embodies the truth that in everything there is manifested a measured motion, to and fro; a flow and inflow; a swing backward and forward; a pendulum-like movement; a tide-like ebb and flow; a high-tide and low-tide; between the two poles (which exist in accordance with the Principle of Polarity). There is always an action and a reaction; an advance and a retreat; a rising and a sinking. This is in the affairs of the Universe, suns, worlds, men, animals, mind, energy, and matter. This law is manifest in the creation and destruction of worlds; in the rise and fall of nations; in the life of all things; and finally in the mental states of Man.
The Hermetists have grasped this Principle, finding its universal application, and have also discovered certain means to overcome its effects in themselves by the use of the appropriate formulas and methods. They apply the Mental Law of Neutralization. They cannot annul the Principle, or cause it to cease its operation, but they have learned how to escape its effects upon themselves to a certain degree depending upon the Mastery of the Principle. They have learned how to USE it, instead of being USED BY it. In this and similar methods, consist the Art of the Hermetists.
The Master of Hermetics polarizes himself at the point at which he desires to rest, and then neutralizes the Rhythmic swing of the pendulum which would tend to carry him to the other pole. All individuals who have attained any degree of Self-Mastery do this to a certain degree, more or less unconsciously, but the Master does this consciously, and by the use of his Will, and attains a degree of Poise and Mental Firmness almost impossible of belief on the part of the masses who are swung backward and forward like a pendulum. This Principle and that of Polarity have been closely studied by the Hermetists, and the methods of counteracting, neutralizing, and USING them form an important part of the Hermetic Mental Alchemy.
The Three Initiates. Kybalion: A Study of the Hermetic Philosophy of Ancient Egypt and Greece (pp. 30-32). Neeland Media LLC. Kindle Edition.