Anima mundi: the soul that gives life to the universe

To imagine the universe as an immense living being was, for many centuries, the most natural thing in the world. If every animal has a soul that moves its limbs, why should the cosmos, which moves with admirable regularity, lack one? From this question springs the notion of anima mundi, the soul of the world, which Renaissance philosophers placed at the heart of their vision of nature and which Cornelius Agrippa regarded as the source of all the hidden virtues of things.

Plato and the demiurge

The founding text is Plato's Timaeus. The demiurge, the divine craftsman, fashions the world as “a living being endowed with soul and intellect” and composes its soul by mixing the same, the different and being according to precise numerical proportions. The soul is then stretched throughout the whole cosmic body and wrapped around it. The dialogue, known in the Latin Middle Ages through the partial translation and commentary of Calcidius, was for centuries almost the only Plato available in the West.

Virgil gave the idea poetic form in the sixth book of the Aeneid, where Anchises explains to his son that a spirit nourishes from within the sky, the earth, the sea and the stars: “mens agitat molem”, mind moves the mass and mingles with the great body. The line, read and commented upon throughout the Middle Ages, became a motto for generations of readers and returned often in the pages of Renaissance philosophers.

From the Neoplatonists to Chartres

Plotinus, in the third century, made Soul the third reality after the One and Intellect: from it the individual souls descend, and to it the living unity of the cosmos is owed. In the twelfth century the masters of the school of Chartres returned boldly to the theme. William of Conches suggested that Plato's world soul might correspond to the Christian Holy Spirit, a reading that drew criticism from William of Saint-Thierry and which he himself eventually toned down.

Ficino, Agrippa and the soul as mediator

Marsilio Ficino, translator of Plato and Plotinus, made the world soul the pivot of a system in which divine ideas are impressed upon matter through vital seeds, the rationes seminales. Agrippa takes up this legacy in the first book of De occulta philosophia: for him the anima mundi is the mediator that transmits to stones, plants and animals the forms coming from the divine mind, using the rays of the stars as their vehicle.

The result is a world in which nothing is truly inert. The properties of a gem or a herb, which Aristotelian science could not explain through hot and cold, become traces of this universal life. Giordano Bruno, a few decades later, would carry the idea to its furthest consequences, speaking of a soul wholly present in every part of the infinite universe.

The world soul left the vocabulary of science with seventeenth-century mechanics, but it did not vanish: we find it again in Romantic philosophy of nature and in Schelling's Weltseele of 1798. To know its history is to understand why, for Agrippa, studying nature and studying the divine were two aspects of the same inquiry.