The Greater Holy Assembly is a book written by S.L. MacGregor Mathers, a prominent figure in the occult and esoteric community in the late 19th and early 20th centuries. The book is a comprehensive guide to the Greater Holy Assembly, a mystical order that Mathers founded and led. The book covers a range of topics related to the Greater Holy Assembly, including its history, philosophy, and practices. It also includes detailed instructions for performing...