Into Italy, Germany, England, Averroism had silently made its way.  It found favor in the eyes of the Franciscans, and a focus in the University of Paris.  By very many of the leading minds it had been accepted.  But at length the Dominicans, the rivals of the Franciscans, sounded an alarm.  They said it destroys all personality, conducts to fatalism, and renders inexplicable the difference and progress of individual intelligences.  The declaration that there is but one intellect is an error subversive of the merits of the saints, it is an assertion that there is no difference among men.  What! is there no difference between the holy soul of Peter and the damned soul of Judas? are they identical?  Averroes in this his blasphemous doctrine denies creation, providence, revelation, the Trinity, the efficacy of prayers, of alms, and of litanies; he disbelieves in the resurrection and immortality; he places the summum bonum in mere pleasure.

So, too, among the Jews who were then the leading intellects of the world, Averroism had been largely propagated.  Their great writer Maimonides had thoroughly accepted it; his school was spreading it in all directions.  A furious persecution arose on the part of the orthodox Jews.  Of Maimonides it had been formerly their delight to declare that he was “the Eagle of the Doctors, the Great Sage, the Glory of the West, the Light of the East, second only to Moses.”  Now, they proclaimed that he had abandoned the faith of Abraham; had denied the possibility of creation, believed in the eternity of the world; had given himself up to the manufacture of atheists; had deprived God of his attributes; made a vacuum of him; had declared him inaccessible to prayer, and a stranger to the government of the world.  The works of Maimonides were committed to the flames by the synagogues of Montpellier, Barcelona, and Toledo.

Scarcely had the conquering arms of Ferdinand and Isabella overthrown the Arabian dominion in Spain, when measures were taken by the papacy to extinguish these opinions, which, it was believed, were undermining European Christianity.

Until Innocent IV. (1243), there was no special tribunal against heretics, distinct from those of the bishops.  The Inquisition, then introduced, in accordance with the centralization of the times, was a general and papal tribunal, which displaced the old local ones.  The bishops, therefore, viewed the innovation with great dislike, considering it as an intrusion on their rights.  It was established in Italy, Spain, Germany, and the southern provinces of France.

The temporal sovereigns were only too desirous to make use of this powerful engine for their own political purposes.  Against this the popes strongly protested.  They were not willing that its use should pass out of the ecclesiastical hand.

The Inquisition, having already been tried in the south of France, had there proved to be very effective for the suppression of heresy.  It had been introduced into Aragon.  Now was assigned to it the duty of dealing with the Jews.