The Kybalion presents seven principles that its authors assert govern all reality: Mentalism, Correspondence, Vibration, Polarity, Rhythm, Cause and Effect, and Gender. These principles operate across every plane of existence — physical, mental, and spiritual. The text argues that understanding them constitutes the "Master-Key" to the doors of the Temple of Mystery. The book draws from the Hermetic tradition that stretches from ancient Egyptian priestcraft through Greek philosophy to the Western esoteric schools. Its central claim is radical: the universe is mental in nature, and mastery of one's own mind is mastery of reality itself.