It is customary to think of the ‘parting of the ways’ within the French Dévot movement in terms of two publications, and the dates on which they first appeared in print. Thus the seminal ‘Jansenist’ works of Cornelius Jansen and Antoine Arnauld, released upon an unsuspecting public in 1640 and 1643 respectively, seemed to bring into existence the Jansenist movement, which was to divide the former unity of the French movement for Catholic reform. Although Anthony Wright does not deny the divisions that emerged in the Dévot movement, or the fatal consequences that these had for its cohesion, his ambition in his latest volume is to demonstrate that the ‘parting of the ways’ was a process that occurred gradually before 1640, and had an existence which was not defined by any text. Just as, therefore, French Catholics allowed themselves the luxury of delighting in the defeat of the Huguenot ‘menace’ in France after the successful siege of La Rochelle, they entered a decade in which they began to experience their own set of internal divisions. Tremendously and often painstakingly detailed, Wright's work charts the development of the fissures within the Dévot movement, focusing his analysis of evidence on the criticism of the Jesuits which dominated public ecclesiastical discourse despite royal protection of the Society, and on the polarising figure of the abbé of Saint-Cyran (Jean Duvergier de Hauranne), one of their chief opponents. By 1643 the Dévot movement was, Wright contends, extremely fragmented as a result of disputes over neo-Molinism and ecclesiology, but it had not yet divided into two parties. Saint-Cyran played a crucial role in the growing disunity; as a prominent figure within several Dévot circles, he led antagonistic attacks on Jesuit articulations of soteriology and pastoral care, and set the scene for the actual separation of Dévots into two factions during the mid-1640s. For Wright, the Jansenist dichotomy of true and false orthodoxy, in which they were the champions of legitimate doctrine, was fatally destructive of the original Dévot vision of an all-Catholic France. Targeted towards the specialist in seventeenth-century French Catholic history, this work repays close attention, because it provides a thorough examination of the disintegration of this vision as the Dévots identified the enemies that they feared stood within their own ranks.