Marsilio Ficino and the Moon: Renaissance natural magic

In Medici Florence, at the end of the fifteenth century, the philosopher and physician Marsilio Ficino developed one of the most influential theories of Renaissance natural magic. A translator of Plato, Plotinus and the Corpus Hermeticum, Ficino imagined a living universe, pervaded by a world soul and by a very subtle spirit linking heaven and Earth. In this animated cosmos the Moon held a strategic position, as the last sphere before the world of the elements.

De vita and the spirit of the world

The work in which Ficino set out these ideas is De vita libri tres, published in 1489 and devoted to the health of scholars, whom he considered prone to melancholy because of their Saturnine temperament. The third book, entitled De vita coelitus comparanda, «on obtaining life from the heavens», discusses how human beings can attune themselves to celestial influences through music, scents, colours and images. The author proceeds with caution, aware of the theological risks.

At the centre of the theory is the spiritus mundi, a substance midway between soul and body which, like the vital spirit in man, was thought to carry the virtues of the stars to earthly things. Ficino drew on Plotinus and the Neoplatonic tradition, but also on medieval astrological doctrines. The Moon, as the nearest planet, was considered the channel through which the influences of the higher stars descended to the elements, a kind of collector and distributor of celestial energies.

The Moon as mediator

In Ficino's vision each planet had a character: Saturn favoured contemplation but bred melancholy, Jupiter and Venus tempered its excesses, the Sun gave vitality. The Moon, swift and changeable, governed growth, moisture and the vegetative functions, that is, the nourishment and development of the body. Her importance came above all from her role as intermediary, since nothing, according to the astrology of the time, came down from the sky without passing through her sphere.

Ficino also drew on Arabic sources, in particular the Picatrix, from which he took certain ideas about astrological images while keeping his distance from it. Not surprisingly De vita aroused suspicion among church authorities, and the author had to defend himself with an Apologia distinguishing his natural magic, based on the properties of things, from the demonic magic condemned by the Church. It is a work to be read as a philosophical document, not as a manual.

The legacy of a vision

Ficino's ideas spread quickly across Europe thanks to printing. Giovanni Pico della Mirandola, his friend and interlocutor, praised natural magic in the Conclusiones of 1486, but later fiercely attacked divinatory astrology in the Disputationes adversus astrologiam divinatricem, published posthumously in 1496. The exchange between the two shows that even in the Renaissance the influence of the Moon and planets was a matter of debate, not of shared certainty.

After Ficino, authors such as Cornelius Agrippa, Giambattista Della Porta and Tommaso Campanella developed in different ways the theme of sympathy between heaven and Earth. Della Porta, in the Magia naturalis published in Naples in 1558, dealt with surprising natural phenomena; Campanella, in the seventeenth century, wrote at length on astrology and celestial influences. In these authors the Moon remained the bridge between the heavenly spheres and the sublunary world, following a model that went back to the ancient philosophers.

Ficino's Moon is not that of modern astronomers, but part of a philosophical cosmos in which everything is connected. Understanding it helps explain why the Renaissance, an age of great scientific and artistic renewal, cultivated natural magic with such passion, seeing in the sky a source of harmony for human life and for the work of the intellect.