This article examines medieval concepts of paternity and father-son relationships through the digital analysis of medieval textual corpora. Although historians have access to enormous digital collections in 2023, they have rarely fully exploited these resources. The author proposes a historical semantic approach to this theme, using modeling tools and text mining in general, to analyze the evolution of terms related to paternity. The study proposes three conclusions: 1. a semantic break occurred in the semantic field of paternity at the turn of Antiquity and the Early Middle Ages. The meaning of pater and its derivatives changed radically over the course of the 4th-6th centuries, particularly as a result of the influence of the dogma of the Christian Trinity. Medieval fatherhood was multidimensional, encompassing both biological and spiritual aspects, in other words, complex relationships between multiple carnal and spiritual (i.e. divine) fathers. 2. The role of spiritual kinship is crucial to understanding medieval fatherhood, as the work of Anita Guerreau-Jalabert and J{\'e}r{\^o}me Baschet has already shown. Initially attributed to God, this ''ideal paternity'' (paternitas) gradually extended to members of the Church (popes, bishops, abbots), underlining at the same time the growing importance of spiritual kinship over biological kinship over the centuries studied. 3. To reveal these structures, invisible to the naked eye, an interdisciplinary approach is rigorously required. Complementary investigations into the lemmas mater, filia, frater and other family terms are required. The use of digital tools and historical semantic analysis opens up new perspectives for researchers in history, anthropology, linguistics and data mining, enabling them to explore the representation systems of ancient societies in depth and with nuance.