Olli-Pekka Vainio sets out to address one of the key questions facing a world of increased fragmentation and religious conflict: how do we handle disagreement virtuously, and deal with its challenges in ways that lead to human flourishing rather than further disintegration? The need for deeper reflection on this is becoming increasingly apparent. Following Peter Berger's thesis that late modernity tends to generate difference (creating a plurality of worldviews, values and viewpoints) Vainio argues that we live in a world where our religious choices make us ‘heretics’ to increasing numbers of people. We therefore need more than ever to understand the nature of our disagreements, and learn to disagree well without losing our conversation partners.

Vainio's project is vital in its contemporary relevance, but the question of how to reconnoitre such complex terrain in a book of 200 pages is clearly a considerable challenge! Given the limited available space, as well as the technical and analytical nature of much of the philosophical discussion, Vainio is to be congratulated on contributing such a clear and generative book for contemporary reflection. Central to its success lies in its identification of disagreement as a discrete subject for interdisciplinary exploration in its own right, and for offering such reflection in a concise and well-ordered way, even if the discussion is in places highly condensed.

The interdisciplinary approach is structured around insights from three broad sources: the history of ideas, contemporary cognitive science and the philosophy of religion. In conclusion, the final chapter advocates the practice of virtue theory as the best way to actualise our responses to disagreement. Chapter 1 (‘We've Been Here Before’) surveys a history of disagreement in philosophical terms ranging from the thought of Plato and Aristotle, through Augustine and Aquinas, to Bacon and Descartes and on into the political philosophies of Hobbes, Locke and Kant. From the supposed zenith in the evolution of the western mind as a result of the ‘Enlightenment’, Vainio proceeds to chart the demise of its central premises, heralded by the rejection of philosophical neutrality by Nietzsche (and therefore of uncontested foundationalist notions of ‘truth’), and materialised more recently through a variety of perspectivist and contingent theories. The result of this, says Vainio, is that ‘The freer people are, the more room they have for disagreement’ (p. 40).

Next Vainio turns to the field of contemporary psychology and examines disagreement through the prism of neuroscience and the psychology of decision-making. Vainio shows that disagreeing is actually intrinsic to mental behaviour in humans, and that our cognitive limitations make rational reflection upon the process of decision-making very difficult. Building on this conclusion with insights from the science and epistemology of religious belief Vainio suggests that part of this complexity derives from the element of mystery which is intrinsic to religious believing.

How then do we hold our beliefs in such a way as to avoid the kind of dogmatism that arises from a lack of humility on the one hand, but also avoid the scepticism about the views of others that results from an overconfidence in the epistemic status of our own beliefs? Vainio's conclusion is that the best way through the dilemmas posed by religious disagreement is through the pursuit of the best insights of virtue theory. For Vainio, this involves the combination of an epistemic humility with personal courage. It is the ability to articulate the strengths and weaknesses of one's beliefs, understand the strengths and weaknesses of another's beliefs, and then bring the two perspectives into a constructive dialogue that ensures a proper and respectful accommodation of difference.

Disagreeing Virtuously is a stimulating and illuminating book, even if one might inevitably have wanted the case to be taken further. For example, many of the discussions betray an understandably western cultural context, in which an individualist rather than communal context tends to be focal. One way of building on Vainio's work would be to consider what other cultural contexts would contribute to the discussion. In addition, given the book's emphasis upon religious conflict from a Christian perspective, more might have been said about the pursuit of virtue in explicitly Christian terms, which the last section just begins to introduce. However, as a road sign towards greater human flourishing in times of disagreement, this book provides both a valuable and detailed map of where we've come from as well as a compass suggesting a way forward.