The author is Professor of Law at the University of Alabama School of Law. The title – consciously echoing Charles Taylor's A Secular Age – may be regarded partly as a lawyer's response to the phenomena upon which that sociologist prolixly mused. Moreover, its context is entirely North American, specifically the religious clauses of the First Amendment to the United States' constitution: ‘Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof’. While some European thinkers get a mention, there is no glance at, let alone analysis of, the jurisdiction of the European Court of Human Rights or the experience of European states. However, despite its apparently limited frame of reference, this dense and energetic work in fact addresses the common substance of how democratic countries may best negotiate the claims of religion in public life.

Particularly critical of the Supreme Court's response to the establishment clause – ‘a farrago of unstable rules, tests, standards, principles and exceptions’ (p 223) – Horwitz's core thesis is that the relevant US jurisprudence has got into an inconsistent, incoherent muddle and, as to ‘constitutional easements’, hypocrisy. It has done so because it has failed to face up to questions of religious truth. The solution is for human rights courts and public officials to take a more empathic agnostic approach to religious argument, listening with more engagement and accommodation short of attempting to determine what religious truth in any instance should be.

The argument proceeds in four parts. Part I, ‘The end of the world as we know it: the collapse of the liberal consensus in law and society’ (Chapters 1–2), describes a liberal consensus which regarded religious belief as an entirely private matter and became in practice secular in its operation. Common theories of religious freedom have become challenged in ways that have made sustaining the former consensus problematic.

Part II, ‘Getting to maybe: the agnostic turn’ (Chapters 3–5), describes empathic agnosticism as a form of open-minded, responsive scepticism and contrasts it with the culture wars between ‘New Atheism’ and ‘New Anti-Atheism’. Applied to affairs of state, empathic agnosticism becomes ‘constitutional agnosticism’, the preferred approach to Church–state issues: ‘It remains open to the possibility that there is some truth out there to be reached, although it does not reach a conclusion about what that truth is’ (p 151). Although not requiring its practitioners to set aside any religious beliefs of their own, and while it cannot be a perfect response to the plurality of religious belief, it is the best approach available where ‘the tension between religion and the state, and especially between religion and the liberal state, is an unavoidable feature of modern existence in our age’ (p 168).

Part III, ‘Putting constitutional agnosticism to work’ (Chapters 6–7), reviews past Supreme Court jurisprudence and indicates where outcomes might have been different under constitutional agnosticism, arguing that ‘relative indifference to the truth of a religious claim tends to privilege the needs of the state over the needs of the religious believer’ (p 173). As to the free exercise clause, the argument is particularly critical of Employment Division v Smith (494 US 872 (1990)) claiming that it meant that ‘religious objectors to a generally applicable law effectively had no rights at all’ (p 179, emphasis in original). Conversely, although constitutional agnosticism would not always benefit the religious believer, ‘it does suggest that [it] places a thumb heavily on the scales of the religious claimant in free exercise cases’ (p 190). As to the establishment clause, Horwitz criticises what he describes as ‘constitutional easement’ – a ‘willingness to uphold government actions, like offering prayers before legislative sessions, that would otherwise contradict the court's Establishment Clause rulings, so long as the government practices have a long pedigree’ (p 233). Constitutional agnosticism would suspend ontological commitment in public speech and, as regards funding, either fund secular and religious bodies on the same basis or fund none at all.

In Part IV, ‘Constitutional agnosticism, religion, and liberal democracy’ (Chapter 8), Horwitz summarises his argument and tries to anticipate and deal with possible criticisms. On the whole, this reader found him less convincing, for example, on defending how far constitutional agnosticism differed from at least some common understandings of liberalism but securer in countering incommensurability arguments. In the end, how far exactly would outcomes differ under the espoused regime? Horwitz himself poses this question when, in his discussion of the establishment clause, he asks what changes will ensue from his argument that government should never endorse religious messages:

Is constitutional agnosticism merely liberalism brought up to date for a pluralised world? At times, a British reader may wonder how far what is being espoused amounts to anything more than alert pragmatism dressed up for local consumption. That said, the book displays a sympathetic, thoughtful and constructive mind at work. The US may seem to be a separate universe but it is merely that the presenting phenomena are different from elsewhere. Though the US may be dogged jurisprudentially by a form of constitutional prescriptivism devised to deal with specific, local political problems of the 1770s and which frames a unique domestic discourse, the essential difficulties now for American and European jurists are the difficulties that confront all liberal democracies. Just as Lorenzo Zucca argues for an ‘inclusive secularism’ in Europe, Paul Horwitz attempts substantially similar things for the US: the language of the discourses may be different but in both cases the means and the ends sought are much the same.