One of the most influential studies of the development of the western church and of its canon law between the ninth and the twelfth centuries has been the Histoire des collections canoniques en Occident: depuis les Fausses Décrétales jusqu'au Décret de Gratien of P. Fournier and G. Le Bras (2 vols. [Paris: Recueil Sirey, 1931–2]). Fournier and Le Bras put forward the case for seeing the great reform of the church in the eleventh and twelfth centuries being carried forward by new collections of law intended to promote papal primacy and to eradicate clerical marriage and lay investiture. Whereas the monumental collection of church law made between 1012 and 1022 by Burchard, bishop of Worms, clarified the responsibilities of bishops, some of the collections made in the eleventh century radically promoted papal primacy and “Gregorian” reforms. The Decretum of Ivo, bishop of Chartres from 1090 to 1115, together with his Panormia and Prologue, also promoted reform and entered the mainstream of academic and practical life in the twelfth century as the “investiture contest” drew to an end. Finally the great Concordance of Discordant Canons produced by Gratian of Bologna in about 1140, which built upon the work of Ivo, closed a long period during which “scholastic” methods for interpreting church doctrine and law had been forged, largely by promoters of reform.

In the present book Rolker mounts a sustained assault on this powerful account. This may not have been his original intention when he embarked upon a study of the canon law content of Ivo's letters. But the results of his studies have catapulted him into a position where the grand narrative of Fournier and Le Bras had to be further reconsidered once it became clear to him that Ivo was not a reformer in the way in which Fournier and Le Bras had represented him nor was he the author of the Panormia nor was the earlier work of Burchard displaced by new legislation. The result is a fine book on at least three levels. The first is the tunneling for sources utilized by Ivo in his correspondence. In a concordance that fills over thirty-five pages, he lists the parallels between quotations found in the letters and in Ivonian collections. The second level is that of Ivo's participation as bishop of Chartres in the great affairs of the French kingdom and church, including his principled but rather isolated resistance to the re-marriage of king Philip I. The third level is one on which a fresh look is taken at the broad outlines of the history of church reform and the stimulus it gave to scholasticism. These seem less linear than they did to Fournier and Le Bras, very great though their achievement was and remains. The key is Rolker's finding that Ivo is not only not the author of the very successful Panormia but also that he never used it and that it was probably completed later than is usually thought, in about 1115. Instead of seeing the Panormia, which depends on the Decretum for some ninety per cent of its material, simply as an abbreviation with a Prologue, Rolker shows that each work employed sources in a distinctive way and that the Prologue belongs to the Decretum. Ivo's purposes and his methods of work should therefore be seen in a different light. Whereas the Decretum and the Prologue accept a plurality of traditions, seeing them as different expressions of divine law, the Panormia reconciles and eliminates contradictions. An example is the problem of marriage after concubinage. Authoritative sources assembled by Ivo in his Decretum show that different rules had been made for dealing with such marriages whereas in the shorter Panormia options are deliberately reduced by the reconciliation and removal of contradictory canons, not merely in the interests of brevity but in the pursuit of greater doctrinal coherence or selectivity. The mainspring for Ivo's Decretum appears to be not so much an interest in shaping scholastic techniques for reformulating apparent contradictions in inherited legal sources as in collecting texts which pastors, guided by charity, will find to be best fitted to individual cases when they choose between “mercy and justice.” Much of the Decretum is about the sacraments, the laws of the church being largely an application of sacramental theology. The polemics of the Berengarian eucharistic controversy of the eleventh century made more of an impact on the writing of the Decretum than did the polemics of the investiture contest.

The removal from Ivo's authorship of the Panormia takes out the main plank on which, Rolker argues, Ivo's reputation rests as a champion of the growing centralism of papal government and as a progenitor of scholastic method. As regards the former, although, as Rolker remarks, Ivo was friendly to papal Rome he was far from Hildebrandine for he challenged Pope Gregory VII's strong views on papal authority and on legatine power, particularly as the latter was exercised by the formidable archbishop Hugh of Lyon. In the mid-1090s Ivo reinterpreted recent papal decrees against lay investiture and in 1108 he argued that the new archbishop of Rheims should swear fealty to King Louis. He was also very skeptical about the crusade movement. As regards Ivo's contribution to the early scholastic movement, which shaped the development of medieval canon law as much as it did the development of medieval philosophy and theology, this is reduced in the light of the findings about the authorship and success of the Panormia. Rolker's very scholarly book in no way reduces the stature of Ivo as a wise, learned, and influential bishop but it leaves us in no doubt that we now live in a post-Fournier world.