Inquisition The Inquisition was a permanent institution in the Catholic Church charged with the eradication of heresies. Unlike many other religions (e.g., Buddhism, Judaism), the Catholic Church has a hierarchical structure with a central bureaucracy. In the early years of the church, there were several competing sects that called themselves Christian. But after the Emperor Constantine I (280?-337 CE) made Christianity the state religion of the Roman Empire and the local administrative structures were pulled together into one hierarchy centered in Rome, doctrinal arguments were settled by Church Councils, beginning with the Council of Nicea in 325 (which formulat