Fr Morerod has made a refreshing and fruitful contribution to ecumenical theology. Perceiving the history of ecumenical dialogue since Vatican II as having fallen into two phases, namely, a rapid rapprochement in discovering common ground, followed by the asking of what are the fundamental differences that still divide the Christian confessions, he suggests in Part I that some of the remaining obstacles to unity which we need to identify may be in themselves philosophical.

Morerod holds that practioners of ecumenical and interrreligious dialogue have employed, whether consciously or not, principles of dialogue which are rooted in the scientific culture that is dominant in our time. He makes his own examination of how philosophers, principally Popper, Kuhn and Feyerabend, have approached the understanding of the relationship between scientific systems. What he discovers is an incommensurability among scientific theories based on the limitation of human understanding, and thus a difficulty in choosing between systems, since each system addresses its own favoured questions which are not easily transferred to another. A crucial point, for Morerod, is that theological questions in demand of ecumenical dialogue differ from scientific ones on account of the fact of revelation by a God whose knowledge is unlimited. Thus Morerod scorns a merely pluralistic yet amiable future for the partners of ecumenical dialogue. However, despite the fact that the key difference here is made by revelation, the distinction between dialogues is not established without the aid of philosophical distinctions.

Not only does Morerod call on philosophy to clarify what is going on in ecumenical dialogue as such, but in Part II he also makes use of philosophy to address a principal question for that dialogue, that is, the historic division over justification. Morerod thinks that, since Luther intended to banish philosophy, the strictly philosophical distinctions between Catholics and Protestants have been ignored by ecumenists. He characterises Luther as having nevertheless imbibed a roughly ‘Scotist’ metaphysics, and he examines the questions that arise about the relationship between God and humanity in a manner not unfamiliar to Thomists. Morerod argues that Luther (and many others) fall foul of a false competition between divine and human action, where something cannot be entirely the work of God and entirely the work of a creature, where a role for the human will in justification is excluded by divine activity. Morerod notes that various moderns have rejected God in favour of human freedom, a choice made on the basis of the same philosophical presuppositions.

Against this false dichotomy and the theological impasse it engenders, he presents Aquinas's understanding of the radical difference between God and humanity, the compatibility of primary and secondary causes, where each in its own order is entirely responsible for an effect, and the notion of instrumental cause, by which the life of grace is well integrated, theologically speaking, into the life of humanity. Morerod suggests that a disengagement by Protestants from the philosophy that has dominated the Reformation and modernity would better serve the very cause of the Reformation. His argument is very much one for Thomism as the solution to ecumenical difficulties, and it makes me wonder what account Morerod would want to give of a healthy theological pluralism. Perhaps he will engage with that question elsewhere – in this book he has already promised to address not only the question of what is the proper goal of ecumenical dialogue but also of what should be the nature of the debate between ecumenical partners over the interpretation of what God has revealed to us.