From the Author: C. S. Lewis' Mere Christianity is the obvious inspiration for the title of this book. In that book, Lewis uses the example of a person standing in a hall that is lined on both sides by rooms: Each room represents a different Christian tradition. He wanted to get readers into the hallway and let them choose for themselves whether to enter Christianity by the door of Anglicanism, Catholicism, and so forth. Mere Christianity brilliantly focuses on what essentially all Christians agree upon; namely the Creed, the canon of the New Testament, etc. However, many of the great controversies between Protestants and Catholics are purposely not discussed. There were ecumenical reasons for avoiding topics like papal primacy, purgatory, Marian devotions, and so forth. But, by avoiding these sorts of topics, Mere Christianity can be read as Mere Protestantism. I wrote Mere Catholicism to address some of those missing topics. Even though I am both intellectually and emotionally convinced of the truth of Catholic Christianity, I am indebted to C. S. Lewis (an Anglican) for helping me better understand how Christianity offers the most compelling raison d'être. His work and I hope my own is an exploration of "faith seeking understanding," to quote St. Anselm of Canterbury.