Ramon Llull

Llull's Art was a serious and strange project. Beginning after a religious conversion in his thirties, and refined across several decades and several versions, it reduced knowledge to a set of basic principles, goodness, greatness, duration, power and the rest, and combined them mechanically through tables and concentric rotating discs, so that the truths of theology could in principle be generated and demonstrated by manipulation rather than assented to on authority. The purpose was missionary: he wanted a method that would compel the assent of Muslims and Jews without appeal to scripture they did not accept, and he learned Arabic for the same reason.

It did not convert anyone, and the modern interest in it is different from his. The Art is a genuine ancestor of combinatorial logic and of the project of a universal formal language; Leibniz read Llull as a young man and his De arte combinatoria acknowledges the debt directly.

One thing needs stating flatly because the tradition has it wrong for centuries. The alchemical works attributed to Llull are not his. A substantial pseudo-Lullian corpus was composed after his death and circulated under his name, and it is the reason he appears in histories of alchemy and in occult reference books as an adept and a transmuter. The historical Llull wrote against alchemy. The attribution is one of the largest and longest-running misattributions in the field, and it is settled.

Llull's eccentric logical machinery had a missionary purpose that is easy to lose. After his conversion at about thirty he set himself three aims and pursued them with total single mindedness for half a century: to write books against error, to found schools of languages, and to die a martyr. The second aim produced Miramar, the college he persuaded the king of Majorca to endow in 1276, where Franciscan friars were to learn Arabic before preaching in North Africa; Llull himself had learned Arabic over nine years from an enslaved Muslim tutor, and wrote some of his works in it first.

The Art, the system of lettered wheels and combinatoric tables for which he is remembered, was designed for exactly this frontier. Its premise is that argument from shared first principles, the dignities of God that Christian, Muslim and Jew all confess, goodness, greatness, eternity, power, wisdom, will, could proceed without appeal to any scripture the other side rejected. It was, in intention, a machine for debating across religions in terms both parties already accepted. He crossed to North Africa to dispute publicly at least three times, was expelled, imprisoned and stoned, and the tradition that he died of injuries received at Bougie in 1315 or 1316, though unverifiable in its details, fits the life he said he wanted. The combinatoric wheels that later fascinated Leibniz were, for their maker, mission equipment.