Ptolemy's Tetrabiblos

Ptolemy’s Tetrabiblos is the classic Greco-Roman treatise on astrology, setting out the theoretical basis for interpreting celestial influence on earthly events. Its historical importance is immense, as it became one of the most influential texts in the astrological tradition; readers will find explanations of planetary qualities, horoscopic methods, and astrological judgments.

Claudius Ptolemy was a Greco-Roman scholar of the second century CE whose works shaped astronomy, geography, and astrology in the classical and medieval worlds. His Tetrabiblos became a foundational text for learned astrology and exerted a long influence on later esoteric and philosophical traditions.