Abstract
This article discusses the notion of what it means to be a Father of the Church as it was accepted and developed in a fifth century document called the Commonitory. This document was a sort of doctrinal and practical manual to distinguish Catholic truth from the errors of heretics. The author, Vincent of Lérins, based himself on the experience he gathered from the Fathers, who were approved and recognized by the authority of the Church, in order to deepen and carry out his theological method. From the various writings studied, the essence, and the principal and constitutive features of what is implied belonging to the Fathers emerge, of what it is that distinguishes them as the spiritual masters of all Christian generations and indispensable points of reference for the life and doctrine of the Church.