Many hypotheses have been made about the identity of those who hid behind the pseudonym "The three initiates". The most common and accepted hypothesis is that the author is William Walker Atkinson, alone or in collaboration with others. In fact, Atkinson was known for his habit of using many pseudonyms depending on the type of public to which each of his works was addressed. The Kybalion first appeared in December 1908. The book claims to be based on the ancient teachings of Hermeticism, however many of the ideas it presents are actually modern concepts developed within the New Thought stream of thought. The central theme of the work is "mental transmutation" (also described as "mental alchemy", "art of mental chemistry", "art of polarization" and "mystical psychology") or the art of modifying and transforming one's own mental states as well as those of others. The book devotes a chapter to each of its seven "principles", or axioms: principle of mentalism, principle of correspondence, principle of vibration, principle of polarity, principle of rhythm, principle of cause and effect, principle of gender.