Auricular confession--the latter as a means of detection, the former as a tribunal for punishment.
In general terms, the commission of the Inquisition was, to extirpate religious dissent by terrorism, and surround heresy with the most horrible associations; this necessarily implied the power of determining what constitutes heresy.

The criterion of truth was thus in possession of this tribunal, which was charged "to discover and bring to judgment heretics lurking in towns, houses, cellars, woods, caves, and fields." With such savage alacrity did it carry out its object of protecting the interests of religion, that between 1481 and 1808 it had punished three hundred and forty thousand persons, and of these nearly thirty-two thousand had been burnt! In its earlier days, when public opinion could find no means of protesting against its atrocities, "it often put to death, without appeal, on the very day that they were accused, nobles, clerks, monks, hermits, and lay persons of every rank." In whatever direction thoughtful men looked, the air was full of fearful shadows.

No one could indulge in freedom of thought without expecting punishment.

So dreadful were the proceedings of the Inquisition, that the exclamation of Pagliarici was the exclamation of thousands: "It is hardly possible for a man to be a Christian, and die in his bed." The Inquisition destroyed the sectaries of Southern France in the thirteenth century.

Its unscrupulous atrocities extirpated Protestantism in Italy and Spain.