The microcosm of Ramon Llull. An introduction to the medieval world view. Translated from the Catalan by Ulli Roth (Q2735979)

The author has produced a welcome addition to the literature on the medieval Catalan philosopher-theologian-poet and erstwhile hermit, Ramon Llull (more often called Raymond Lully in English), born on Mallorca in the 1230s and stoned to death by the Saracens in 1315. Llull's forays into the realms of mathematics were most often astrological or numerological, with only meager contributions to what we might call mathematics today. There are attractive diagrams of his on the ``four elements'' and of the universe (with astrological overtones), the latter being precursors of what appear later in the cosmological work of Clavius. Some of the diagrams suggest figurate numbers, but it appears that little mathematics actually comes of it.NEWLINENEWLINENEWLINEStill, Llull did have the germ of an interesting mathematical idea in his Ars Magna of 1305-1307, the development of a mechanical device in which subjects and predicates of theological propositions are arranged geometrically so that mechanically certain conclusions could be reached on theological questions. It was in a way a proving machine, a very early version of what others would try to develop hundreds of years later.NEWLINENEWLINENEWLINEReaders of this volume will, however, be mainly those interested in Llull's philosophical and theological thought.