John O'Malley has made major contributions to church history in several fields during a long and distinguished career undiminished into his ninth decade and now, in his tenth, he is setting out an account of that career and the intellectual drive that lay behind it. The fields he has advanced include Italian Renaissance thought, the history of the Jesuits, early modern art history and religion and the history of councils from the sixteenth to the twentieth century, many threads of which are gathered in a magisterial overview, Four cultures of the West, published in 2004. In this book he returned to a central concern of his, the dominant relationship of form in shaping the understanding of concepts in theological, and other areas, of knowledge. It is a plea for recognition of the importance of rhetoric in the advancement of understanding. How to distil all this achievement within one small volume? There is something of the American dream in this account of a clever small-town boy, the only child of nurturing parents, who by dint of hard work and talent conquered his chosen world. But O'Malley is too generous to lay this all at his own door. His parents were merely the first nurturers, and due credit is given to others, most notably his first supervisor Myron P. Gilmore, and his wife Sheila, and the Society of Jesus. These are important reference points, for they establish that scholarly endeavour is best undertaken in supportive social environments, and in O'Malley's life there have been many such. This is no surprise for those of us who have heard him speak, for his grace and clarity of expression enhance any social group. These gifts also distinguish his writings. Within this account there is also something of the picaresque. The story is often advanced by apparently sudden changes of intellectual focus following chance encounters, a notice in a Harvard hallway or chance meetings with scholars who point him in directions he had not thought of himself. There is undue modesty here, as well as generous recognition of the roles played by others, for nobody familiar with O'Malley's work can fail to recognise that it is driven by a clear intellectual agenda, perhaps not fully formed ab initio, but his doctoral topic on Giles of Viterbo suggests that it was present early on. That purpose was to stress the fundamental importance of rhetoric, the need to understand how things were said in order to understand fully what was being said, or trying to be said, in the past, whether by artists or by cardinals in councils. This point is stressed in this book, but not discussed at length and for that, as for any scholar of O'Malley's stature, the best way to understand his work is to read the volumes. These are neatly stacked in the cover photograph which, surprisingly to this reviewer, omits two of his most influential volumes, Praise and blame in Renaissance Rome and Trent and all that. To many early modernists his coining of ‘early modern Catholicism’ in the latter opened an interpretative framework in which to place their work and, in O'Malley's phrase, rescue the Catholic Reformation from its previous role as ‘the ugly step-sister’ of the Reformation. That alone would be enough to justify a career but, as O'Malley's work and his story here suggest, there was much more.