Catoptromancy: divinatory mirrors from Patrae to John Dee

The mirror is an ambiguous object: it shows the world, but reversed; it returns the face, but in a depth that does not exist. Catoptromancy, from the Greek katoptron, «mirror», is divination carried out by observing reflecting surfaces, such as metal mirrors, polished stones, shiny blades or vessels filled with water. The practice has a long and well-documented history, running from Greek antiquity to the Elizabethan court, by way of medieval clerics and their young assistants.

Demeter's mirror at Patrae

Pausanias, in the seventh book of his Description of Greece, describes an oracle at the sanctuary of Demeter in Patrae, in Achaea. In front of the temple there was a spring. Whoever wished to know the fate of a sick person lowered a mirror tied to a thin cord so that it barely touched the surface of the water. After praying and burning incense, they looked into the mirror, which showed the patient either alive or dead. Pausanias specifies that the oracle answered only questions about illness.

The account is interesting because it combines water and mirror, showing how close hydromancy and catoptromancy were. The rite was limited to a precise question and took place in a recognised sanctuary, without the mediation of a professional soothsayer. It was the enquirer who looked into the mirror and recognised the image, after performing the acts of devotion required by the sacred place.

Children and specularii

In the Roman period catoptromancy also appears in historical sources. The Historia Augusta, a collection of imperial biographies of debated reliability, relates that Emperor Didius Julianus, in AD 193, consulted a mirror in which a blindfolded boy was said to see the future. The detail of the child recurs often: innocence was thought to make one better suited to perceiving visions.

In the Middle Ages clerics called those who practised this art specularii. John of Salisbury, in the Policraticus, written around 1159, recounts an episode from his own childhood: a priest who taught him the psalms used him and another boy to gaze into basins and polished surfaces. John recalls that he saw nothing and was excluded, later interpreting that experience as a danger narrowly escaped.

John Dee's obsidian mirror

The most famous object linked to catoptromancy is the obsidian mirror associated with John Dee, mathematician and adviser to Elizabeth I. It is a disc of polished obsidian of Aztec origin, which probably reached Europe after the Spanish conquest of Mexico. Today it is kept in the British Museum in London, together with other objects connected with Dee's experiments.

In the 1580s Dee held, with his associate Edward Kelley, long sessions in which Kelley claimed to see and hear angels in stones and reflecting surfaces, while Dee wrote everything down. The diaries of those sessions have survived, and part of them was published in 1659 by Méric Casaubon, with critical intent. They are among the most detailed sources on Renaissance scrying.

Catoptromancy thus accompanies the whole of European history: from Demeter's spring to the studies of an Elizabethan mathematician. In every age the mirror remained the symbol of a knowledge both desired and feared, able to show what the ordinary eye cannot see. It is no accident that literature, from fairy tales to the Gothic novel, made it one of its favourite magical objects.