Aurora consurgens, the alchemy attributed to Thomas Aquinas

'Aurora consurgens', the rising dawn: with these words, taken from the Song of Songs, opens a medieval alchemical treatise that for centuries was attributed to Saint Thomas Aquinas. The attribution is now considered false, but the text remains one of the most singular in alchemical literature, because it fuses the language of the laboratory with that of the Bible and of mysticism.

An illustrious and unlikely attribution

The treatise, written in Latin, circulated under the name of Thomas Aquinas, the great Dominican theologian who died in 1274. Modern scholars regard it as a pseudepigraphon, that is, a work attributed to a famous author to give it authority, a very common practice in medieval alchemy, where texts circulated under the names of Albertus Magnus, Ramon Llull and Arnau de Vilanova. Its date of composition is uncertain.

The first part of the text is built as a long meditation on Wisdom, woven from quotations from the wisdom books, the Psalms and the Song of Songs. Wisdom speaks in the first person and is identified with the secret of the philosophers' stone, in an interweaving of mystical language and alchemical symbolism that has few parallels. The second part is more technical and traditional in character.

The Zurich manuscript

The best-known copy is an illuminated manuscript of the early fifteenth century, kept at the Zentralbibliothek in Zurich and coming from the Benedictine abbey of Rheinau. Its illustrations are among the oldest figurative series in European alchemy and show symbolic figures, animals, royal couples and a hermaphrodite figure, images that would become common in later treatises.

The miniatures do not illustrate laboratory procedures but concepts: the union of opposites, the death and rebirth of matter, the dual nature of substance. They are therefore an important document for understanding how medieval alchemy built its own language of images, before printing multiplied its versions across Europe. In many of them the sun and moon appear as the protagonists of a cosmic drama.

Jung's reading

In the twentieth century the Aurora consurgens attracted the attention of the Swiss psychologist Carl Gustav Jung, who saw in alchemical symbols the expression of psychic processes. His collaborator Marie-Louise von Franz prepared an annotated edition, published in 1957 as the third volume of Jung's Mysterium Coniunctionis. That psychological reading is one of many possible ones, and must be kept distinct from the history of the text.

Von Franz also suggested that the treatise reflected a mystical experience of Thomas himself in the last months of his life, when, according to his biographers, he stopped writing after a vision. It is an evocative thesis but is not shared by historians, who remain cautious about the author's identity and the date. The debate, however, had the merit of drawing attention back to a text long neglected by scholars.

The Aurora consurgens shows how thin the boundaries between theology and alchemy were in the Middle Ages. For its readers the transformation of matter and that of the soul could be told in the same words, borrowed from Scripture, and illustrated with the same images of kings, queens and rising suns. Its modern fortune springs precisely from this ambiguity.