Published in 1908 by "Three Initiates," the Kybalion presents itself as a summary of the ancient Hermetic philosophy of Hermes Trismegistus, transmitted through secret initiatic lineages for millennia. In reality it is almost certainly the work of William Walker Atkinson — a prolific Chicago lawyer turned New Thought writer who published dozens of books under various pen names. The ancient lineage is fictional. The seven principles it describes are mostly real Hermetic ideas, selectively chosen and repackaged. And the book became one of the most widely read esoteric texts of the 20th century regardless.
The identity of the "Three Initiates" was considered a great mystery for decades. Scholarly investigation has now established almost beyond doubt that the primary author was William Walker Atkinson (1862–1932) — a Chicago lawyer who became one of the most prolific New Thought writers in history, publishing under at least a dozen pen names including Yogi Ramacharaka, Theron Q. Dumont, and Magnus Incognito. Atkinson wrote prolifically on everything from raja yoga to memory training to personal magnetism.
The claim of ancient Hermetic lineage is almost certainly false — no such lineage has been documented, and the specific synthesis the Kybalion presents doesn't match the actual ancient Hermetic texts (the Corpus Hermeticum, the Emerald Tablet) in ways that would be expected if it genuinely derived from them. The book is better understood as a New Thought synthesis that used Hermetic language as its framing device.
Does it matter? The principles themselves are largely sound as philosophical propositions — most appear in some form in genuine ancient Hermetic, Neoplatonic, or Eastern philosophical texts. The book's influence on 20th-century esotericism is undeniable. The question is whether the fictional ancient lineage claim matters. It arguably does — because it encouraged readers to treat the text as received ancient wisdom rather than one man's synthesis, which is a different kind of authority carrying different epistemic weight.