Investigating heresy was the work of the medieval inquisition. But before going into the founding of the inquisition we need to ask what is meant by “heresy”? The word “heresy,” in its origins, means “choice.” Choice implies, therefore, different ways of thinking about a specific subject. The question then arises as to how acceptable different or divergent opinions are, particularly when a community is built on accepted beliefs. Not surprisingly, as Christianity developed there was concern about divergent theological opinions that might damage the Christian community. Theological opinions that were widely divergent came to be seen as destructive and were thus condemned as “heretical.” For example, in the Letter to Titus, one of three pastoral letters of Paul, the writer emphasizes the need for commonality of belief to help the new church on Crete develop appropriately: “As for yourself, you must say what is consistent with sound doctrine (2.1) … After a first and second warning, break off contact with a heretic, realizing that such a person is perverted and sinful and stands self-condemned” (3:10).
Heresy was very important in the early centuries of the Church as it forced the clarification and definition of doctrines. Once Christianity became the official religion of the Roman Empire, it became easier to impose conformity of belief. The civil authorities might consider heresy a crime against the state, meriting confiscation of property, or even death. That however did not mean the end of people thinking and theologizing beyond the accepted parameters of Church teaching. By the time of the Middle Ages, heresies fell into two basic types.
The first type of heresy has to do with those who maintained that the Church in their time was not functioning as its founder had meant it to function, and along with their dissatisfaction were willing to reject traditional teachings. One example is the Waldensians. The Waldensians began as a group of orthodox laymen concerned about the increasing wealth of the Church. As time passed, however, they found themselves stepping beyond the bounds of orthodoxy. A separate page has been created concerning that group.
Catharism represents the second strand of heresy, i.e., those who call themselves Christians but differ with Christianity on fundamental points. The Cathars, for example, while basing their teaching on specific parts of the Bible, in fact believed in two Gods as opposed to one. Again a separate page has been created concerning the Cathars.
The Waldensian and Catharist heresies led Pope Gregory IX to establish a special tribunal called the inquisition, a judicial procedure aimed at investigating and ascertaining the orthodoxy of someone accused of heresy. This tribunal or court functioned in France, Italy and parts of Germany and had pretty much ceased operation by the early fourteenth century. The Spanish Inquisition, authorized in 1478, was quite distinct from the medieval tribunal.
Staffed by Franciscans and Dominicans, the medieval inquisition imposed penances short of capital punishment. Those who refused to retract their errors were handed over to the civil authorities for execution.