This book makes a striking contribution to the history of public religion in the United States in the mid-twentieth century. But the territory which Patrick Hayes navigates so impressively in these 400-odd pages has a bolder significance which extends far beyond such geographical and chronological considerations. The creation of the Catholic Commission on Intellectual and Cultural Affairs in 1946 occurred when American Catholics were looking to establish the intellectual integrity of their faith in the public sphere and, at the same time, to fashion a bolder course for Catholics in the public life of their country. If it was a learned society of a sort, it was an impressively well-furnished one. The breadth of the body was essential to its argument: far from affirming the old powers of clericalism and orthodoxy it instead integrated the assorted ideas of clergy, academics, writers, government administrators, thinkers, scientists and artists. The agenda was purposefully a broad one: it sought to improve the academic claims of Catholic universities and colleges; it at once voiced the claims of intellectual freedom and sought to support the work of displaced scholars who had fetched up on American shores; it turned sharply to questions of Church and State; it was explicitly internationalist and dedicated to the work of the new United Nations Organisation. This generosity of intent would be matched by the palpable vigour of the enterprise: much was done in the way of conferences, lectures, seminars, publications. Far from fragmenting into self-regarding disciplines, as any tidy specialist might glibly have predicted, the Commission was effective in showing that there could be such a thing as distinctive, and credible, Catholic thought in the United States. Moreover, it could be said to be coherent and creative. Accordingly, it is no surprise to find the council pioneering a new Catholic Encyclopaedia of 15 million words emerging out of the combined labours of 4,800 scholars from no less than forty-three countries. By the time that this monumental apotheosis appeared, in 1967, the CCICA had over-taxed itself and run into buffers of various kinds, not least ecclesiastical ones. Nevertheless, across two decades it had been the achievement of the commission to play a crucial part in lifting American Catholicism out of something of a defensive – even ‘defiant’ – backwater, bringing it confidently into the mainstream of national life and culture. In submerging himself in a still uncatalogued archive and writing such an original book, Patrick Hayes has brought a vital, even brilliant, subject out into the open light of international scholarship. Such fine, and potent, work should surely come to matter.