St. Robert Bellarmine's work in defense of the saints, their place in heaven, their canonization and veneration, etc., ranks like all of his works among the classical works of Catholic Theology.

In this work, Bellarmine meets the attack of Protestantism against Catholic teaching on the saints, firstly on their own ground with sound Scriptural Exegesis, backed up by the witness of the Greek and Latin Church.

The great counter-reformation doctor begins the work with a treatise on whether the souls of the saints receive a particular judgment and go to heaven or await for the end of time suspended as it were in some hidden place; then what canonization is, who does it and what is its authority; then lastly, whether the saints may be venerated and invoked.