Inquiring 'whether any war can be just', Thomas Aquinas famously responded that this may hold true, provided the war is conducted by a legitimate authority, for a just cause, and with an upright intention. Virtually all accounts of just war, from the Middle Ages to the current day, make reference to this threefold formula. But due in large measure to its very succinctness, Aquinas's theory has prompted contrasting interpretations. This book sets the record straight by surveying the wide range of texts in his literary corpus that have bearing on peace and the ethics of war. Thereby emerges a coherent and nuanced picture of just war as set within his systematic moral theory. It is shown how Aquinas deftly combined elements from earlier authors, and how his teaching has fruitfully propelled inquiry on this important topic by his fellow scholastics, later legal theorists such as Grotius, and contemporary philosophers of just war.

Winner, 2017 Choice Outstanding Academic Title

'The most comprehensive treatment on this subject to date, Thomas Aquinas on war and peace fills a significant lacuna in research on Thomas and the just war tradition … This volume will be a valuable resource for those interested in him, the history of just war philosophy, or Catholicism. With no comparable volume in English, this book leads one to wonder how we have gone so long without such a work … Essential …'

J. M. Meinert Source: Choice

'… the best account so far of why it is important to appreciate the centrality of the virtues, and the importance of charity, in understanding Aquinas on just war.'

Source: Notre Dame Philosophical Reviews

'This is, simply put, one of the best books on the ethics of war to emerge in the past decade, and it should be essential reading for every scholar interested in just war theory. Lest there be any confusion, when I write ‘every scholar', this is not shorthand for ‘every historian of the just war tradition', or ‘every exegete of Thomas Aquinas'. The title of the book is unhelpful in this regard: it lends the impression that this is a book with a very narrow or even arcane focus. This could not be further from the truth. The book does not treat the analysis of Aquinas’s writings on just war as an end in itself, but rather as a springboard for a far-reaching yet incisive account of just war theorizing from the Middle Ages right up to the present day. Accordingly, when I write that this book is essential reading for every scholar interested in just war theory, this is exactly what I mean.'

Source: Ethics and International Affairs

'This is a fine book - the scholarhip is impressive, the writing and argumentation clear. It goes into enough depth, and breaks enough new ground, to make it profitable to specialists; at the same time, it would, with the aid of a guide, be accessible to intelligent undergraduates. Its combination of historical survey with exploration of contemporary issues would make it an excellent text for an upper-level course in military ethics.'

Christopher Toner Source: American Catholic Philosophical Quarterly