The course Rationes seminales in the early Christian authors focuses on the study of this philosophical and theological concept originated in Stoic philosophy and adapted by the Church Fathers. The course examines how writers such as Justin Martyr, Clement of Alexandria, and Origen adopted and adapted this concept to articulate the relationship between Christian faith and pagan philosophy. Special attention will be given to Saint Justin Martyr, the first to mention the seeds of the Word in relation to the Greek philosophers Plato and Aristotle. Additionally, the encyclical Fides et Ratio, which integrates faith and reason as complementary tools for approaching divine truth, and Pope Benedict XVI’s Regensburg address, which emphasizes the importance of religion in the history of philosophy, will be explored. Through metaphysics and religion, the course helps reason reach otherwise inaccessible places.