Over the last two decades there has been a quiet renaissance concerning Karl Barth's ethics. This renaissance can be described as quiet because it has largely remained an in-house conversation among Barth scholars. The broader Christian ethics guild has given little attention to Barth or the recent re-examination of his ethics. This situation is rather ironic as the reassessment among Barth scholars aims to demonstrate, in contrast to the initial judgement that Barth was averse to traditional ethical reflection, that he can be situated within the mainstream of traditional Christian ethics.

With this monograph, Gerald McKenny – with remarkable success – offers a challenge to both approaches. His primary goal is to demonstrate to contemporary Christian ethicists that Barth is a first-tier moral theologian, securing for his ethics a status similar to that held by the rest of his theology. In addition, while appreciative of and building upon the recent reassessment, McKenny questions if the Barth studies crowd has ‘succeeded only too well’. In short, he wonders if Barth has been made all too palatable according to the norms of Christian ethics, drawing attention away from the radicality and relative strangeness of his moral vision and thus obscuring the very contributions his work makes.

The volume is a delight to read and the depth of engagement is breathtaking. McKenny provides both a conceptual and genetic-historical account of Barth's moral theology. While the emphasis is on the former and the book is conceptually rather than developmentally structured, McKenny takes his readers on a tour of the vast Barthian corpus which deftly narrates the development of Barth's moral vision. As a result, readers with either or both interests are well served. Moreover, throughout, McKenny puts Barth into conversation with contemporary Christian ethical reflection. Additionally, he engages with nearly all the relevant secondary literature on Barth's ethics available in English and German.

One of the many features worth highlighting is McKenny's insightful depiction of Barth's moral theology as both deeply rooted in a Reformation conception of grace and also thoroughly modern. The former claim is uncontroversial. Barth's Reformation emphasis on grace is well known. As is his argument that the good is not something human beings strive after aided by divine grace, but that rather the good is that which is accomplished by Jesus Christ and which subsequently confronts and questions human beings with the demand that they correspond to it in their moral lives. For Barth, ethics is not about determining what do to in order that we might obtain the good through our actions, rather it is about recognising that the good has already been accomplished by what God has done for us in Jesus Christ and, in turn, leading a life which affirms and bears witness (‘corresponds’ in Barth's language) to what God has done. Ethics then cannot be about the human act of distinguishing and judging between good and evil, for such knowledge coincides precisely with the Fall and moreover what Barth takes to be representative of autonomous self-legislative agent which is the norm of modern ethical reflection. McKenny notes that Barth's narrative of modernity shares much with those genealogies (e.g. MacIntyre) which bemoan the state of modern ethical reflection. In McKenny's narrative, however, Barth argues that modern autonomous self-legislation was already latent in premodern ethics. For Barth, the medieval age shares with the modern the notion that the good is something which is accessible to human beings as autonomous self-legislating agents capable of judging between good and evil. For Barth it is the Reformation emphasis on grace which stands out in the history of moral reflection as opposed to such autonomous self-legislation. But since the Reformation emphasis on grace was soon eclipsed by rationalism and pietism, Barth does not simply go back to the Reformers to repair modern ethics, rather he attempts to do so on modern soil. He proceeds largely by pitting Kant against latter developments, namely Fichte. For Barth, Kant depicts the moral law as a confrontation with another which calls human beings into question, whereas Fichte depicts the moral law as self-posited and representing bourgeois self-confidence. This Kantian–Fichtean axis is a constant feature behind Barth's moral reflection and his criticism of bourgeois society and demonstrates that he was a thoroughgoing modern thinker engaged with modern problems. McKenny opines that Barth's distinctively modern idiom, which privileges modernity epistemologically, might be cause for some wariness and may be a feature of Barth's account which is in need of repair and further development. McKenny's analysis of Barth's indebtedness to Kant and his subsequent Kantian anxieties goes beyond any literature hitherto available and is a genuine contribution to Barth scholarship.

Barth scholars will no doubt have some criticisms. One which stands out is the rather puzzling criticism – albeit an entirely accurate description in light of Barth's ‘hyper-Protestant’ emphasis on grace as unmerited and extra nos – bemoaning Barth's utter rejection of deification. There are several such criticisms and suggestions which remain at the level of undeveloped asides. Hopefully, we will be treated to future contributions from McKenny which further develop these and other themes.

McKenny has written an unparalleled introduction to and analysis of Barth's moral theology. This volume exhibits a commanding knowledge of Barth's corpus from the pre-Romans period though the posthumous sections of the Church Dogmatics. It is well written, relatively free of ‘Barthian’ jargon and thus accessible to the more general audience, and contains a nearly comprehensive introduction to the moral theology of the twentieth century's most significant theologian. McKenny's account is highly appreciative of Barth's moral vision but falls short of a full endorsement. Throughout, he sympathetically critiques Barth's moral reflection and suggests how it might be amended, corrected and repaired. Such rehabilitative work, argues McKenny, will not only secure Barth a permanent place in the canon of Christian ethics but also moves towards a truly viable alternative to the traditional Augustinian understanding of the relationship between divine and human action. McKenny hints, in the conclusion, that such work is necessary if the Reformation teaching on grace and justification, so ably defended by Barth, is to continue to have a future voice in the universal church. This volume will soon be recognised as the standard benchmark and essential reading among publications concerning Barth's ethics. It will therefore be of little surprise that the book is strongly recommended to any and all who have interest in contemporary moral theology and/or the legacy of Karl Barth.