In this Theological treatise St. Robert Bellarmine takes on Protestant as well as Greek Orthodox objections to the Papacy in five books. In the first, he argues that Christ established the Primacy of Peter by means of an Ecclesiastical Monarchy, why it is fitting that the Church's government should be a monarchy; Exegetical Commentary on the Lord's words in Matthew 16 and John 21, along with copious Patristic testimony. In Book 2 is whether Peter has successors in the Ecclesiastical Monarchy, wherein Bellarmine defends the Church's position on the true history of Peter; that Peter truly went to Rome; that Peter was truly a Bishop there. In Book 3 Bellarmine shows the Pope is not Antichrist. In Book 4, Bellarmine argues why the Pope is infallible when he defines a doctrine on faith and morals and proceeds to defend Popes whom Protestants and others argued had erred while defining faith. In book 5, Bellarmine takes up the question of the Popes' power in civil affairs.

This catechism can be considered as a valid and effective catechetical tool for the work of the evangelization, a work which has to be realized with a new missionary zeal towards those who don't know the Catholic faith and as well towards those who know it defectively and insufficiently. May those who will read this catechism and those who will use it in the noble and meritorious work of teaching Christian doctrine, may be equipped with the sure and sacred doctrine of the Catholic faith, in order to stand, having their loins girt about with truth. -Bishop Athanasius Schneider This is the first English translation of St. Robert Bellarmine's Long Catechism, which follows a traditional question and answer model but gives deep meditations on the truths of faith. It was written for students with some education as well as for those who would teach Catechism. It was explicitly approved by Pope Clement VIII and praised by Pope Benedict XIV and Pius XI. St. Robert Bellarmine is a doctor of the Church.

St. Robert Bellarmine is perhaps one of the greatest controversial writers of all time. Though a humble, short and unassuming Italian Jesuit, he came to dominate the European theological scene. Bellarmine proposes 15 Marks all of which are an extension of the 4 marks which are put forth in the Nicene-Constantinoplan Creed. In proposing each mark, Bellarmine examines what it entails, how it is proved in the history of the Church and how it disproves the teachings of Protestantism. This is more than an apologetic work, however, as it also brings to the fore many important distinctions of consequence in Theology.