AbstractThis is a Research Note about the ongoing Project on the semantics of pactism (pactisme) in Catalan ancient law. Pactism is the name of the legal doctrine that grounds the validity of legal provisions upon a pact-based model. It was developed as a basis for Catalan Public law in the 13th, 14th and 15th centuries. We present it as a medieval realism. Looking at the concomitances of 20th century legal realism and the doctrine of pactism can shed light on the emergence of early states and the construction of legal doctrines stemming from the reception of Roman law, the wide use of ius commune, and the development of case-based law and Scholastic reasoning methods. The semantics of pact-modelling processes and outcomes has yet to be established. Thus, it is also contended that Digital Humanities can offer some technological solutions to unravel underlying linguistic, cognitive and ontological patterns to understand the political culture that came out of it and developed until the 18th c. in Catalonia.