This book emphasises the primary importance of Hermetism in Renaissance thought. The Hermetic treatises were believed to be by an ancient Egyptian, prophet of Christianity; these associations strengthened their enormous impact on Ficino and the Neoplatonic movement. Pico della Mirandola yoked Hermetism with Cabalism and the Hermetic-Cabalist tradition continued as an "occult philosophy" both magical and mystical. Giordano Bruno is here for the first time placed within the context of this tradition of which he represents an original variation. He emerges as a Hermetic philosopher and magician with an unorthodox religious message. Even his support of Copernican heliocentricity is associated with Ficino's solar magic. This revolutionary reinterpretation pro-foundly affects our understanding of Bruno and of his death at the stake. The Hermetic tradition is followed beyond the death of Bruno into the seventeenth century, particularly in Campanella. The correct dating in 1614 of the Hermetic treatises marked the end of the dominance of Hermetism though it continued to exert a hidden influence. The controversies of Fludd with Mersenne and Kepler arc seen as a conflict between a late revival of the Hermetic-Cabalist tradition and the seventeenth-century scientific movement. Renaissance Hermetism stimulated new attitudes towards the cosmos and towards operating with cosmic forces.
The book is an attempt to restore a missing, or at least neglected, chapter, in Western intellectual history. The "Hermetic Tradition" in the title is the set of beliefs about the supposed Hermes Trismegistus which Renaissance Europe inherited from the Church Fathers. They variously saw him as an ancient Prophet, and the real source of Plato's philosophy, and perhaps the disciple of Abraham or Moses, maybe even their teacher; or as a wicked tool of Satan. When Greek manuscripts of supposed Hermetic texts became available in Florence, the Medici put a priority on translating them, instead of Plato or Plotinus, and Marsilio Ficino obliged, launching a wave of excitement among some European thinkers.