Liber Hermetis

The Liber Hermetis (The Book of Hermes), also known as the Centiloquium of Hermes or Astronomical Hermetica, is a medieval Latin astrological text attributed to Hermes and preserved in manuscript tradition. The work presents astrological doctrine and technical exposition of planetary influences and their effects on sublunary events. The Liber Hermetis represents the astrological branch of Hermetic tradition — the application of Hermetic philosophical principles to the technical practice of astrology. The work circulated among medieval and Renaissance astrologers as an authoritative source on Hermetic astrological theory and practice, establishing Hermes as a central authority within the astrological tradition.

Content and Doctrine

The Liber Hermetis addresses the influence of planets and celestial configurations on human affairs, weather, health, and all terrestrial phenomena. The work emphasizes the correspondence between celestial and sublunary realms, presenting astrology as a science grounded in understanding these cosmic relationships. The text provides practical astrological instruction — methods of calculation, interpretation of planetary positions and aspects, determination of auspicious and inauspicious times for various actions. The work integrates astrological technique with Hermetic metaphysical principles, presenting astrology as an expression of divine order operating throughout creation.

Transmission and Manuscript Tradition

The Liber Hermetis survives in Latin manuscript tradition from the medieval period onward, circulating among astrologers and scholars in European universities and learned circles. The work was attributed to Hermes, lending it authority as an ancient wisdom text. Medieval and Renaissance astrologers cited the Liber Hermetis as an authoritative source, integrating it into their broader engagement with Hermetic and astrological learning.

Modern Scholarship

Medieval and early modern astrology scholarship has recognized the Liber Hermetis as a significant text within the tradition of astrological learning. Contemporary research has examined the work's doctrinal content and its role in transmitting Hermetic astrological theory to medieval and Renaissance Europe. The Liber Hermetis remains an important source for understanding how Hermetic philosophy was applied to technical astrological practice.

Literature

North, John D. Horoscopes and History. London: Warburg Institute, 1986.

Porreca, David. The Emerald Tablet and its Interpretations: From Hermes Trismegistus to Isaac Newton. Oxford: Oxford University Press, 2018.

Saif, Liana. The Science of the Gods: Early Islamic and Late Antique Cosmologies of Light. Berlin: De Gruyter, 2019.

van Bladel, Kevin. The Arabic Hermes: From Pagan Sage to Prophet of Science. Oxford: Oxford University Press, 2009.