In appointing the Dominicans and the Franciscans to suppress heresy, Gregory IX did not dream of abolishing the episcopal Inquisition. This was still occasionally carried on with its rival, whose procedure it finally adopted. Indeed no tribunal of the Inquisition could operate in a diocese without the permission of the Bishop, whom it was supposed to aid. But it was inevitable that the Inquisitors would in time encroach upon the episcopal authority, and relying upon their papal commission proceed to act as independent judges. This abuse frequently attracted the attention of the Popes, who, after some hesitation, finally settled the law on this point.
"If previous orders requiring it" (episcopal concurrence), writes Lea, "had not been treated with contempt, Innocent IV would not have been obliged, in 1254, to reiterate the instructions that no condemnations to death or life imprisonment should be uttered without consulting the Bishops; and in 1255 he enjoined Bishop and Inquisitor to interpret in consultation any obscurities in the laws against heresy, and to administer the lighter penalties of deprivation of office and preferment. This recognition of episcopal jurisdiction was annulled by Alexander IV, who, after some vacillation, in 1257 rendered the Inquisition independent by releasing it from the necessity of consulting with the Bishops even in cases of obstinate and confessed heretics, and this he repeated in 1260. Then there was a reaction. In 1262, Urban IV, in an elaborate code of instructions, formally revived the consultation in all cases involving the death penalty or perpetual imprisonment; and this was repeated by Clement IV in 1265. Either these instructions, however, were revoked in some subsequent enactment, or they soon fell into desuetude, for in 1273, Gregory X, after alluding to the action of Alexander IV in annulling consultation, proceeds to direct that Inquisitors in deciding upon sentences shall proceed in accordance with the counsel of the Bishops or their delegates, so that the episcopal authority might share in decisions of such moment."[1]
This decretal remained henceforth the law. But as the Inquisitors at times seemed to act as if it did not exist, Boniface VIII and Clement IV strengthened it by declaring null and void all grave sentences in which the Bishop had not been consulted.[1] The consultation, however, between the Bishop and Inquisitor could be conducted through delegates. In insisting upon this, the Popes proved that they were anxious to give the sentences of the Inquisition every possible guarantee of perfect justice.