The Importance of Ptolemy’s Tetrabiblos

With sensitivity comes an awareness of the divine order. This belief in the divine order finds its practical manifestation in astrology, the study of the heavenly bodies and their symbolic application to human personality and destiny. It is believed by many that this divine order is reflected through the physical system surrounding us. Scientists observe and experiment to discover the order of this divine system. Astrologers observe the stars to see how this regularity relates to the order of their own existence. It is the object of this exploration to elicit the essences of this astrology.

 “The first modern astrological textbook, the Tetrabiblos, is attributed to the great astronomer, mathematician, and geographer Claudius Ptolemy, who was born in Alexandria. Ptolemy, one of the leading intellectuals of his day, worked between AD 150-180 establishing principles of cosmic influences, which lie at the heart of modern astrological practices." (Parker, p16)

Because this book has supplied many of the foundations of astrology, it will serve as the main essence around which this paper will revolve. Ptolemy of Alexandria recorded the astrological synthesis that occurred at this time of the Chaldean, Greek, and Egyptian star systems. Not only did he record the techniques by which this new simplified method could be achieved, but he also argued the case of astrology in an extremely clear and systematic way. This multi-cultural synthesis by Ptolemy has proved so vital that his landmark book was considered an astrological bible until the 15th century (Ptolemy, X, introduction by Robbins). The Tetrabiblos, although its emphases are different and certain astronomical details were as yet unknown and hence misunderstood at that time, remains perfectly relevant to the foundation of modern astrology. It included all the tools of modern astrology, i.e., the horoscope, the zodiac, the planets, the houses, and the angles or aspects. Ptolemy’s Tetrabiblos acts as a switch in time, reflecting an ancient order and supplying a modern foundation. What are its foundations? (See The Chaldean Contribution.)