Ramon Llull: From the Ars Magna to Artificial Intelligence presents Llull as a pivotal precursor of formal reasoning, whose medieval project unexpectedly anticipates central ideas in logic, computation, and artificial intelligence. The core concept is the Ars lulliana, a universal method designed to analyse fundamental concepts, represent them through symbolic notation, and recombine them by rule-governed procedures in order to generate rational conclusions. Originally intended to persuade Muslims and Jews through shared principles rather than scriptural authority, Llull’s system exceeded its missionary context by proposing a general science of knowledge. Its most innovative feature lies in its combinatorial architecture: letters, diagrams, rotating figures, tables, binary and ternary relations, and structured questions operate as instruments for producing and testing arguments. A decisive case study is Llull’s alphabet of principles, in which concepts such as goodness, greatness, difference, concordance, virtue, and vice are formalised and recombined, thereby prefiguring later aspirations toward a universal calculus. The volume explicitly connects this legacy to Leibniz’s characteristica universalis, Frege’s formal logic, graph theory, semantic networks, generative systems, and even social choice theory. Yet Llull’s thought remains distinct from modern computation because his elementary language is not anti-metaphysical; it is grounded in a theological vision of reality as relational, ordered, and intelligible. Ultimately, Llull’s significance lies in converting reasoning into a mechanisable art of discovery, making him not a modern computer scientist, but a profound ancestor of algorithmic thought.