The identity of Three Initiates has been the subject of much secrecy and rumor since The Kybalion first appeared at the beginning of the twentieth century. It is now believed that William Walker Atkinson was one of or perhaps the sole author of the book. Born in 1862, Atkinson was a pioneer of the New Thought movement who wrote an estimated 100 books during his lifetime.

William Walker Atkinson (1862—1932) was a noted occultist and pioneer of the New Thought Movement. He wrote extensively throughout his lifetime, often using various pseudonyms. He is widely credited with writing The Kybalion and was the founder of the Yogi Publication Society.