Cover of Ptolemy's Tetrabiblos

Ptolemy's Tetrabiblos

by Ptolemy

Reading level
Fairly demanding
Price
Free

About the book

"Ptolemy's Tetrabiblos: or Quadripartite, being four books of the influence of" by Claudius Ptolemy is a text on astrology written in the 2nd century CE. This companion volume to Ptolemy's astronomical masterwork Almagest shaped astrological practice for over a millennium. Ptolemy systematically arranged astrological techniques and defended the subject through natural philosophy, explaining celestial influences using Aristotelian principles. The work profoundly influenced medieval Islamic and Christian thought, earned theological acceptance, and became required reading at Renaissance universities, leaving an enduring mark on Western culture and modern astrological practice.

  • Astrology

Updated September 2026. Public domain in the USA. Text and summary from Project Gutenberg eBook #70850. Ptolemy's Tetrabiblos on Wikipedia.