The term inquisition can refer to either an investigation by the Roman Catholic Church into accusations of heresy, or to the department appointed to perform such investigations. The original purpose of the inquisition was to protect the rights of the accused against unrestricted harsh prosecution by secular rulers and princes (the State). The Office of the Inquisition is currently titled the Congregation for the Doctrine of the Faith since 1965, but was formerly been titled the Supreme Sacred Congregation of the Holy Office, and prior to that the Supreme Sacred Congregation of the Roman and Universal Inquisition. The Inquisition has been the subject of polemic against the Catholic Church by Protestants, and has been carefully studied and demythologized by professional historians and scholars of different faiths and backgrounds to clear away inaccuracies, exaggerations and misunderstandings of the actual facts of the matter. Their findings have been disputed by some, even when indisputable evidence has been found and published, independently corroborating their research.
Several major inquisitions took place, under the management of differing departments.
Many of these inquisitions are known to have used brutal torture to extract confessions from accused heretics. While many of these accused heretics would be allowed freedom after repenting their views and stating their loyalty to the Church, a significant number - consisting almost entirely of those who refused to repent - were executed by a variety of deliberately painful methods including burning at the stake while alive, boiling in oil and the 'breaking wheel.'
Execution was never carried out by the church directly for theological reasons, but by secular authorities. This procedure was clarified in the Ad exstirpanda papal bull written by Pope Innocent IV in 1252, which also authorized the use of torture for extracting confessions from the accused and recommended burning at the stake as the appropriate punishment for those found guilty and unrepentant. Ad exstirpanda marked the beginning of one of the most brutal periods of Inquisition.
The sufferings and martyrdoms of Protestants are recounted in Foxe's Book of Martyrs. The persecutions of Anabaptists and other radical dissenters from earlier centuries is chronicled in the more extensive work, Martyr's Mirror. Both works have been subjected to critical historical analysis and have been found by non-Catholic scholars to be poorly researched, flawed, inaccurate, and most of their descriptions of persecutions exaggerated, while the fact of bloody and violent persecution is not disputed.
The best known of the four major inquisitions was the Spanish Inquisition, which ran from 1438 onwards. One of its primary tasks was enforcement of the Alhambra Decree by the monarchs of Spain in 1492, ordering the immediate expulsion of all Jews from the country and its territories.
The Office of the Inquisition would not be established until 1542 by Pope Paul III, with its stated objective "to maintain and defend the integrity of the faith and to examine and proscribe errors and false doctrines.'
In 2000, a team of 30 scholars from around the world came together to investigate the facts of the matter. In 2004 they made their report, an 800-page tome that was unveiled at a press conference in Rome. Its most startling conclusion is that the Inquisition was not as bad as most people had been led to believe. Torture was rare and only about 1 percent of those brought before the Spanish Inquisition were actually executed. Claims that over 300,000 to 50 million people had been unjustly executed for heresy were debunked as falsehoods. The book's editor, Professor Agostino Borromeo, claims that in Spain only 1.8% of those investigated by the notorious Spanish Inquisition were killed.
Among the best recent books on the subject are by two non-Catholic professors of history. Edward Peters, from the University of Pennsylvania, is the author of Inquisition (Berkeley: University of California Press, 1989). Henry Kamen, a Fellow of the Royal Historical Society and professor at the University of Wisconsin–Madison, wrote The Spanish Inquisition: A Historical Revision (New Haven: Yale University Press, 1998). On page 87 of his book, Dr. Peters states:
- “The best estimate is that around 3000 death sentences were carried out in Spain by Inquisitorial verdict between 1550 and 1800, a far smaller number than that in comparable secular courts.”
Likewise, Dr. Kamen states in his book:
- "Taking into account all the tribunals of Spain up to about 1530, it is unlikely that more than two thousand people were executed for heresy by the Inquisition." (p. 60)
- "Is there scholarly consensus on the historicity of Foxe's Book of Martyrs?" (christianity.stackexchange.com).
- The most careful examination of Foxe's methods is to be found in Maitland, Essays on the Reformation in England (1849), and in Gairdner, History of the English Church from the ascension of Henry VIII to the Death of Mary (1903); Lee in Dict. of Nat. Biog. Gerard, John Foxe and His Book of Martyrs (Catholic Truth Society, London), includes the opinions of a number of Foxe's critics.