The learned magic encompasses significant portions of what more particularly can be identified as natural magic, image magic, astral magic, divination, alchemy, and ritual magic. These forms of magic were informed not only by the rediscovered texts of ancient Greece and Rome but also by the commentaries and treatises produced by Muslim and Jewish scholars in more recent centuries. Astral magic was related to astronomy and astrology, that is, the study of celestial bodies, their movements, and their influences on the human world. Alchemy, the science of transforming natural substances into other substances, constitutes a fifth form of learned magic. Ritual magic concerns itself with the conjuration of spirits, both good and evil, for particular tasks through complex ceremonies. Neo-Platonism inspired Renaissance thinking about magic in many ways, none of which was more influential, than Hermeticism.