Raymond Lulle

Ramon Llull (; ; – 1316), sometimes anglicized as Raymond Lully, was a Catholic philosopher, theologian, poet, missionary, apologist and former knight, born in Palma de Mallorca. He invented a philosophical system known as the Art, conceived as a type of universal logic to prove the truth of Christian doctrine to interlocutors of all faiths and nationalities. The Art consists of a set of general principles and combinatorial operations. It is illustrated with diagrams.

A prolific writer, he is also known for his literary works written in Catalan, which he composed to make his Art accessible to a wider audience. In addition to Catalan and Latin, he also probably wrote in Arabic (although no texts in Arabic survive). His books were translated into Occitan, French, and Castilian during his lifetime. Although his work did not enjoy huge success during his lifetime, he has had a rich and continuing reception. In the early modern period his name became associated with alchemical works.

More recently he has been recognized as a precursor of the modern field of social choice theory, 450 years before Borda and Condorcet's investigations reopened the field. His ideas also prefigured the development of computation theory. Venerated as a saintly figure in the Catholic Church, he was beatified by Pope Pius IX in 1847. He was a member of the Third Order of Saint Francis.