Ramon Llull (Raimundus Lullus, 1232-1316) is one of the most innovative figures of medieval philosophy and theology. As a lay philosopher and theologian he wrote more than 280 works in Catalan, Latin and possibly also in Arabic, in an attempt to convince Muslims and Jews by means of strictly rational arguments of the truth of Christian dogma. This 'Compendium of Key Texts' offers the very first comprehensive account of Raimundus Lullus's theological thought, based on a systematic selection of original texts along with English translations.