Albertus Magnus between Natural Science and Books of Secrets

Few medieval names appear as often on the title pages of books of secrets as that of Albertus Magnus. Yet the German Dominican, born in Swabia around 1200 and who died in Cologne in 1280, was first of all a theologian and a tireless naturalist, teacher of Thomas Aquinas and commentator on the whole of Aristotle. The Church canonised him in 1931, proclaiming him a doctor; popular culture, long before, had made him a magician.

An Encyclopaedist of Nature

Albert taught in Paris and Cologne and was bishop of Regensburg for two years. His project was to make the whole of Aristotle's natural philosophy accessible to Latin readers, supplementing it with his own observations. This produced works such as De vegetabilibus, De animalibus and De mineralibus, in which the author often distinguishes what he has seen with his own eyes from what he has only read or heard.

In De mineralibus Albert also discusses the virtues attributed to stones and the images engraved on gems, citing ancient and Arabic sources. He does not accept them all, but neither does he reject them wholesale: for a thirteenth-century philosopher occult properties were a natural phenomenon to be explained, tied to the form of substances and the influence of the heavens, and not necessarily the work of demons.

The Speculum astronomiae

Among the works linked to his name, the most important for the history of magical books is the Speculum astronomiae, probably written in the 1260s. The treatise aims to separate licit astrology, regarded as part of science, from the books of necromancy that usurp its name. To do so it lists and describes dozens of texts then in circulation, attributed to Hermes, Solomon, Ptolemy and Arabic authors.

The Speculum is thus a kind of first critical catalogue of books of image magic, invaluable to historians because it records titles and opening words of works we would otherwise barely know. Its authorship, however, has long been debated: some scholars consider it Albert's, others the work of an author from his circle or slightly later. The question remains open, and the oldest manuscripts are not enough to settle it.

Pseudo-Albert and the Books of Secrets

Larger still is the corpus of apocryphal texts. The Liber aggregationis, also known as the Secreta Alberti, collects the supposed virtues of herbs, stones and animals; De secretis mulierum deals with generation in language that made it a text both medical and licentious. Both circulated in hundreds of manuscripts and printed editions in the fifteenth and sixteenth centuries under the saint's name, but they are not considered his work.

The fortune of pseudo-Albert continued into the modern age. In France, from the eighteenth century, the popular booklets of the Grand Albert and the Petit Albert spread, sold by pedlars and read in the countryside. They were miscellaneous collections of household recipes, curiosities and superstitions that no longer had any link with the theologian of Cologne, apart from the name printed on the cover.

The gap between the historical Albert and the Albert of the booklets is huge, but not accidental. The authority of the great naturalist, who had truly written about the virtues of stones and plants, made any secret attributed to him believable. Following his figure through the centuries means watching how an illustrious name can become a guarantee of quality for texts of an entirely different nature.