St. Robert Bellarmine, S.J. (1542-1621) was the chief Catholic theologian during the latter part of the sixteenth century and at the beginning of the seventeenth century. His literary production was immense, since he produced books and treatises on most areas of theology, including Scripture, Christology, Sacraments, Liturgy, Ecclesiology and Eschatology. Among his major works are the three Controversies contained in this series. Controversy II contains Bellarmine's defense of the Church's teaching on the divinity and humanity of Christ. In great detail he refutes the sixteenth century heretics who deny either the divinity of Jesus or his humanity.

He also proves the distinction of the three persons in the Trinity and shows that the Second Person, or Word of God, is the one who assumed a human nature and is Jesus of Nazareth. He also presents arguments to prove that the Holy Spirit proceeds from the Son and that there is full justification of the addition of the "filoque" to the Nicene Creed. In all three Controversies he is refuting the errors of many adversaries of the Catholic Church. His favorite targets are Martin Luther and John Calvin. Robert Cardinal Bellarmine was greatly admired by bishops and Catholic theologians during his lifetime and was famous for his scholarship and preaching. He was the theologian and counselor for several Popes. He was called another Augustine, another Athanasius. He was greatly detested by Protestants because of the power of his arguments to prove that they were in error.