Ptolemy's Tetrabiblos: Or Quadripartite, Being Four Books of the Influence of the Stars ... with a Preface, Explanatory Notes, and an Appendix Containing Extracts from the Almagest of Ptolemy and the Whole of His Centiloquy, Together with a Short Notice of Mr. Ranger's Zodiacal Planisphere and an Explanatory Plate

The Tetrabiblos is the foundational text of Western astrology, written by the same Claudius Ptolemy who gave us the geocentric model of the universe. Composed around 150 CE, it represents the most ambitious ancient attempt to systematize celestial influence as a legitimate discipline. Ptolemy argues that the Sun, Moon, and planets affect earthly matters through their inherent qualities of heat, moisture, and dryness - that the stars are not mere decorations but active agents shaping weather, character, and collective destiny. He distinguishes between what can be reliably predicted (general atmospheric and seasonal effects) and what remains more speculative (individual natal charts), defending astrology as worthy of serious intellectual inquiry. For over a millennium, this treatise served as the essential authority for astrologers, physicians, and natural philosophers across the Islamic world and Renaissance Europe. This edition presents the complete four books with scholarly apparatus, allowing modern readers to encounter the work that shaped how generations understood humanity's connection to the cosmos. Whether you approach it as history of science, cultural artifact, or living tradition, the Tetrabiblos remains the essential starting point for understanding how ancient minds read the heavens.