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 until the time when the loss of Latinity relegated him to a more general obscurity.
On the Marks of the Church is the 4th book of Bellarmine's 2nd volume of the Controversies. In it, he 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.
Cardinal Franzelin taught, in his work De Divina Traditione, that the teaching of the Theologians often serves as a foundation for later Ex Cathedra definitions of Popes and Councils. Just as St. Thomas Aquinas featured so prominently at the Council of Trent so also Bellarmine, more than any other theologian influenced Vatican I.
In On the Marks of the Church, Bellarmine proposes 15 Marks of the True Church, Catholicity; Antiquity; Long Duration; The Multitude of Believers; Apostolic Succession of Bishops; Agreement with the Ancient Church; The Unity of the Church; The Holiness of Doctrine; The Efficacy of Doctrine; Holiness of the Fathers; The Glory of Miracles; The Light of Prophecy; Confession of our Adversaries; The Unhappy End of Those who Oppose the Church; and at length, The Happiness of Those who Defend the Church. In proposing these Marks, Bellarmine presents what they entail, how the Catholic Church is described by each of these Marks, and refutes Protestant teaching or attacks upon these specific Marks, in his usual style of quoting the Protestant author at length and in context, then refuting their arguments with the clear light of Holy Scripture and the Church Fathers.
In this highly readable translation, provided by Ryan Grant (The Translator for the Canisius Catechism), you can read firsthand Bellarmine's mastery of the Scripture and the Fathers as he combats the errors of his day which, more often than not, are the errors of our own day or at least their root.