Dion Fortune 
Mystical Qabalah [EPUB ebook] 

Very few students of occultism know anything at all about the fountain-head whence their tradition springs. Many of them do not even know there is a Western Tradition. Scholarship is baffled by the intentional blinds and defences with which initiates both ancient and modern have wrapped themselves about, and concludes that the few fragments of a literature which have come down to us are medieval forgeries. They would be greatly surprised if they knew that these fragments, supplemented by manuscripts that have never been allowed to pass out of the hands of initiates, and completed by an oral tradition, are handed down in schools of initiation to this day, and are used as the bases of the practical work of the Yoga of the West.