Aurelius Ambrosius was a fourth century cleric who rose to become the Archbishop of Milan in 374 AD. His father was a powerful Roman general and the prefect of Gaul. His brother and sister were also consecrated as saints by the Catholic Church. As an infant, a swarm of bees settled over his face and flew away without harming the baby, but left behind a drop of honey and this was seen as a sign of his future eloquence and bees are often painted in his portraits as his symbols.

Ambrosius (or Ambrose as he is referred to in English) was a highly learned man, well versed in Latin and Greek, theology and many other subjects. His great achievement was to establish the Catholic church in Milan and reduce the powerful Arian sect to secondary status in the state. He ranks with greats like Augustine and Jerome in his learning and devotion to the church. In fact, he was the priest who baptized Augustine. He was also a notable Biblical critic and initiated several innovative ideas that would help guide State-Church relations in medieval times. He was also a gifted orator and skilled musician, and many of his hymns are remembered even today. He was responsible for introducing a new style of “antiphonal” chanting in the Church.

On the Duties of the Clergy was published in about 391 AD. It was written to motivate the clergy of his diocese so that they would conduct their lives in a manner appropriate to their vocation. With his immense background in the Classics, Ambrose modeled his treatise on Cicero's De Officiis. Hence, the Latin title of his work is De Officiis Ministorum.

He begins by reiterating that what he is about to say has already been taught to his clergy, but he would like to refresh their memory and ensure that they have indeed imbibed the right lessons. One of the devices he uses to convey his teachings is by replacing the old Roman heroes with Old Testament saints. On The Duties... is divided into three main books. In the first book he describes duties which are “ordinary” and those which are “perfect.” Duties to parents, elders, and the cardinal virtues are discussed here. In the second book, he looks at the “expedient” aspects of life. The third book deals with “duties of perfection.” He exhorts the clergy to consider not only what is duty, or perfect or expedient, but to ascertain what is good for all.

As an early piece of ecclesiastical writing, On the Duties of the Clergy makes interesting reading whether you're drawn to religious writings or not.