Nicholas of Cusa (1401–64) was not only one of the greatest theologians of Europe in the late Middle Ages, a promoter of what is often called a ‘mystical theology’, but he was also a leading figure of the fifteenth-century movement towards church reform. Richard Serina has taken him up in this latter role, seeing him in the context of the breadth of late medieval and high-Renaissance reform. Here, Cusanus cuts a most peculiar figure, since he started out as an avowed conciliarist at the Council of Basel only to end up as a full-blown papalist long before the council drew to an ignominious close. Serina focuses on his later, papalist years as an activist reform-minded bishop of the diocese of Brixen in the Tyrol, where he was resident from 1452 to 1458, and then as a cardinal in Rome responsible for the reform of the clergy of the great basilicas. Serina manages to reinterpret both the ideological grounding and the intellectual import of Cusanus’ reform measures in those years, so that he becomes one of the most interesting of the reformers of his generation and a spokesperson for a model of reform that would be influential long after his death.

The backdrops for Serina's efforts are two standard views in modern scholarship of Cusanus’ career as a reformer. The first sees him as irreconcilably bipolar: on the one hand ‘an unqualified conciliarist with an unqualified corporatist, egalitarian ecclesiology’, on the other hand, and later, ‘an unqualified papalist with an unqualified hierocratic, monarchical papalism’. The second and not unrelated view paints him in his late years as a reformer who was inflexible and authoritarian, a person whose reform actions could not be traced back to his philosophical and theological speculations. Serina believes that both views fall wide of the mark. He notes that current scholarship has already begun to turn towards that conclusion. But he takes up the novel argument that it was during his Brixen years that Cusanus began to work out a vision of reform that belies both of the previously standard views, and he shows how the evidence for this conversion can be found in a series of sermons delivered in the Brixen days to the laity of his cathedral, the religious of the monasteries of his diocese and to the assembled clergy at several diocesan synods. Moreover, Serina ties the move towards a new conception of reform to a development in Cusanus’ thought. He says that it was during his Brixen years that Cusanus returned to the mystical theology of Pseudo-Dionysius and there found the stimulus for a reform agenda that was not rigidly authoritarian but rather grounded in ‘a mystical view of salvation’ that ultimately ‘level[led] the ecclesiastical hierarchy such that both clergy and laity [found] themselves in the same relation to Christ’ (p. 185).

It is an ingenious argument, and in a close reading of both Cusanus' career and his Brixen sermons Serina marshals a convincing defence of it. The catalyst for Cusanus’ embrace of novel ideas of reform was the resistance that he faced to his initial efforts to reform the clergy, both regular and secular, in his newly assumed diocese. As chapter ii of the book reveals in graphic detail, the local or diocesan politics of the Church in the fifteenth century were remarkably complicated, making smooth sailing of measures for reform practically impossible. Stymied on the political front, Cusanus returned to Pseudo-Dionysius for a vision of the ecclesiastical hierarchy that constituted less a descending line of jurisdiction and more a sacramental and vocational invitation to a common pursuit of the exemplar of Christ. Making use of a distinction between a potestas ordinis, or sacramental function, and a potestas iurisdictionis, or jurisdictional function, of the government of the Church, Serina insists that Cusanus laid the emphasis on the jurisdictional side in his early years and found that bias confirmed in the hierarchies of Pseudo-Dionysius. On this basis, church reform would depend upon stressing obedience – with the regular clergy, for example, obedience to their rule and to their superiors. Beginning in the 1450s, however, Cusanus began to read Pseudo-Dionysius’ hierarchical schemes as signifying a descending distribution of grace, an illumination that brought the power of God down to the lowest ranks so that they, in turn, would have the means to rise back up into the Godhead. As Serina puts it, Cusanus now fuses the jurisdictional and the sacramental functions, calling for a reform that eschews simple obedience and favours a configuration that unites all members of the Church in the ecclesiastical corpus mysticum. From this perspective, the reformed and reforming Church would be expected more to serve a mediating function.

Ultimately, then, what might appear in the political struggles of the reform-directed bishop of Brixen as an authoritarian bent is revealed in his sermons to be a call for exemplification and imitation. Serina comments on how by the end of his episcopacy Cusanus has come to see the key to reform as consisting in the notion of Christiformitas, the coming to be a likeness of Christ. This means for Cusanus that as Peter came to be like Christ by devoting himself to his vocation as preacher and servant of the Christians around him, so the bishops should become Christiform by imitating Peter, and the general clergy the same by imitating the bishops. It is in his sermons, and not his ecclesio-political acts, that Cusanus lays out the recipe for such an imitative and unifying reform, and it is in sermonising that he thinks that the clergy will best be able to play this role. As Serina so eloquently puts it, ‘The clergy find their place not primarily in the governmental structure of the church, but in their illuminative function as teachers of Scripture who facilitate the attainment of the body's mystical union with its head’ (p. 120). So, in the end, Cusanus the reformer remains true to the insights of his mystical theology. Despite his efforts, however, Cusanus failed to see his reform implemented in either Brixen or Rome. But he did leave to Europe a model that would be returned to by reformers in succeeding centuries.