
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.