The article focuses on the formation of priestly ethics in late antiquity, more specifically at the end of the 4 th century. In his work De officiis, in which he draws heavily on the homonymous work of Cicero from more than three centuries ago, the bishop of Milan, Ambrosius, creates an interesting fusion between the ethical ideals of Roman pagan society and Christian doctrine based on biblical revelation. The virtues and values in which he wants to educate his clerics, the new emerging spiritual elite, turn out to be very similar to those found in Cicero: whether it is practical advice on speaking (rhetoric) or a general theoretical perception of morality. Despite the many similarities with Cicero, Ambrose serves up some more typically Christian ethical nuances: celibacy occupies a high place, otium becomes prayer and meditation, and verecundia receives an even stronger internal emphasis.