Esoteric Astrology is Volume III of A Treatise on the Seven Rays. In this book, astrology is described the science of relationships--the relationship existing between all living organisms within the universe. Not only the qualities of the ray energies affect these centres of consciousness, but also the quality and energy of the ruling planets and the zodiacal signs. Seen from the exoteric outside, astrology is a vast and most involved and complex subject. From the esoteric inside, while it is still vast, all-inclusive and complex. It is also possible to perceive the thread which unites and the pattern which prevails throughout the whole system. A basic simplicity in the grand design emerges, therefore, which can serve to interpret the whole. The appendix summarises and tabulates many factors of fundamental importance to the study of esoteric astrology.