In most accounts of the Reformation, Cajetan (Tommaso de Vio) is presented as one of a phalanx of almost indistinguishable Italian Thomist Dominicans who confronted Luther in the early years of his revolt. There is some truth in the stereotype, in that Cajetan was brought into the Luther affair fresh from completing his commentary on the Summa theologiae. But it hardly does justice to a man who was one of the most thoughtful of Luther's opponents, who was as critical as he was of indulgence theory and practice, and who strove unsuccessfully to ensure that papal condemnation of the reformer was not an act of sheer negation but contained reasoned argument as well.

There have been attempts to rehabilitate the cardinal before, most notably by Jared Wicks. Michael O'Connor builds on these and on his own previous studies to take the process of rehabilitation a stage further, by examining a less well-known aspect of Cajetan's scholarly activity: his commentaries on most of the books of the Bible. For a busy papal courtier, Cajetan produced them astonishingly quickly. Starting work in 1524, he had completed the Psalms by 1527, the whole of the New Testament bar Revelation by 1529, and the Old Testament up to Isaiah (excluding the Song of Songs) by 1534. This work rate is the more astonishing when one realises that these years span the Sack of Rome, when the elderly Cajetan was shamefully abused by the emperor's troops, and his subsequent convalescence.

Cajetan's exegetical labours are often explained in terms of his anti-Reformation campaign: it is assumed that, having found the appeal to Thomism useless when engaging with Protestants, he turned to the study of the Scriptures to forge new weapons. O'Connor shows convincingly that this explanation overlooks Cajetan's lifelong concern with biblical studies, and that the intent of his exegesis was not so much to combat heresy as to serve pastoral ends, as a good Erasmian humanist. In this sense, O'Connor claims, Cajetan's Bible commentaries should be seen as ‘more a work of “Catholic Reform” than “Counter-Reformation”’ (p. 1).

O'Connor shows that Cajetan's biblical commentaries focus on establishing the literal sense, though the definition of what is literal could be ‘comprehensive’ at times (p. 194). As a result, Cajetan's interpretations show evidence of remarkable freedom in some respects. For instance, he reasoned that Christ's forbidding a man to leave his wife except on the grounds of her infidelity meant that divorce was allowable under some circumstances. In this he was opposed by what he called ‘a torrent of doctors’. Even more surprisingly, given that the ‘bread of life’ discourse in John vi was everywhere being traded in the eucharistic controversies of the day, Cajetan denied that the chapter had anything to do with the Lord's Supper. And his commentary on Romans is so pointedly directed against renascent Pelagianism that it ‘implicitly makes common cause with Lutheranism’ (p. 111).

The commentaries were completed in time for Erasmus to praise them. Otherwise, Cajetan's achievement could hardly have been received less favourably. Luther famously jested over the dinner table that ‘Cajetan has finally become Lutheran!’ What he did become was ‘the most read Thomist’ in Calvin's Geneva (p. 243), despite the care with which he demonstrated his conformity with the Church's faith and deferred to papal scrutiny of his work. Fellow Catholics savaged him for his alleged exegetical dependence on Erasmus, Lefèvre and even Luther: censures poured forth from Rome, from Paris and from German Catholics. Trent's decrees of 1546 against the private interpretation of Scripture are normally assumed to have been directed at the memory of Cajetan. But O'Connor argues that the cardinal was vindicated by the passage of time: his attention to the text of Scripture and to the primacy of a literal, historical interpretation adumbrated Pope Pius xii’s encyclical Divino afflante spiritu, which in turn laid the foundations for the emergence of Catholic biblical scholarship in the 1960s.

O'Connor's study is a first-class addition to the canon of Cajetan scholarship, and a very worthy inclusion in the St Andrews Studies in Reformation History series. It succeeds in adding a sometimes surprising new dimension to our knowledge of the Italian Thomist Dominicans. This achievement is helped enormously by the author's winning prose style, which brings to life what might have seemed a dry subject: for instance, who could have guessed that, at the time of his Proverbs commentary, the cardinal was a recent convert to the advantages of washing with soap? The editors and publishers should also be congratulated for an attractive and near-flawless product, the misspelling of Prierias's Aurea rosa (p. 56) being the only thorn that I noticed.

The book is not beyond criticism. In particular, the survey of Cajetan's motives for writing the Bible commentaries in part ii of the monograph fails to distinguish his purpose from that of most contemporary, humanist-inspired, church writers: all claimed that their works were for the good of others, and especially of the Church, and certainly not for their own aggrandisement; all excoriated the faults of the different estates and recalled them to true piety. Part iii, on method, gives a much clearer sense of Cajetan's uniqueness. The assessment of Cajetan's exegetical ‘afterlife’ is generally very useful. But here there is a danger of claiming too much for him, if he is seen as the progenitor both of literal approaches to Catholic biblical criticism and of more recent approaches which ‘transcend the letter’, endorsed by Benedict xvi’s encyclical Verbum domini (pp. 254–7). One could make the same claim for Aquinas himself, perhaps with more justice. But this is to carp. O'Connor has put us all in his debt for a stimulating study with nuggets to be discovered on almost on every page. For instance, towards the end of the book the author suggests that a comparison of Cajetan the Erasmian Thomist with the former Dominican Martin Bucer would be ‘especially intriguing’ (p. 252). Indeed it would.