It has been said of Saint Irenaeus that “The Church is fortunate that Irenaeus was involved in many of its controversies in the second century. He was a student, well trained no doubt, with great patience in investigating, tremendously protective of apostolic teaching, but prompted more by a desire to win over his opponents than to prove them in error.” In this course we are going to look at the life of this great Saint, and his writings, to understand why the Church recently declared him the “Doctor of Unity,” and why the challenges he faced and overcame can provide us with wisdom on how to live and share the Catholic faith in our own time and culture, which in many ways is similar to his!