: This book focuses on events affecting entire regions or nations. It explores how celestial phenomena like eclipses and comets influence wars, famines, and the weather.
: Ptolemy defends astrology as a legitimate, though less certain, science compared to astronomy. He introduces the "powers" of the planets based on physical qualities—such as heat, moisture, dryness, and cold—and describes the nature of the zodiac signs. Ptolemy's Tetrabiblos, Or Quadripartite
Ptolemy systematically organized the astrological knowledge of his time into four distinct sections: : This book focuses on events affecting entire
He viewed astrology as a practical science similar to medicine—conjectural rather than absolute—because individual results could be modified by factors like race, upbringing, and geographical location. Historical Legacy He introduces the "powers" of the planets based
: The final book examines external life events, such as wealth, social status, marriage , and travel. Scientific and Philosophical Approach
Unlike his predecessors, Ptolemy attempted to ground astrology in the of his time. He used Aristotle’s concept of the four elements and the four humors to explain how the "emanations" of the planets physically affected the Earth's atmosphere and, by extension, human bodies.