The editors of this collection of essays clearly set out its aims in an extensive introduction. They build on work which establishes the importance of heterodoxy in natural philosophy to identify its influence on other disciplines, such as moral philosophy, law and history. One central aim is to remind historians of political thought that they ought not to neglect religion. Another is to provide a sophisticated account of the relationship between heterodox theology and enlightenment and so to disabuse us of the notion that heterodoxy was necessarily a precursor of secularisation.

In the main, the volume's essays look towards England and the Dutch Republic, though Enrico Nuzzo has contributed a chapter on Italy. The introduction ranges much more broadly: from fourth-century Nicaea and the establishment of orthodoxy in the early Church, to the Reformation and Counter-Reformation. The ‘Christian framework’ (p. 9) created by medieval scholars to demarcate the domains of nature and of grace and to coordinate the claims of the Church and civil power is treated only briefly, despite the editors' presenting the breakdown of this system as a main factor in the later proliferation of heterodox theologies. The third section of the introduction is helpful in setting out treatments of the relationship of nature and grace after the Reformation, particularly those of Jansenists and Socinians. The introduction identifies a second main intellectual consequence of heterodoxy. This is ‘the unravelling of the integrity of the biblical text’ (p. 39). Here we are provided with a survey, which draws mainly on works of secondary scholarship in English, of several important biblical critics, particularly Louis Cappel, Jean Morin and Richard Simon. An additional chapter on the relationship between biblical criticism, heterodoxy and secularisation could have served the editors' aims well.

The tendency to treat biblical criticism less comprehensively than other points of concern is reflected in the volume as a whole. Indeed, Hans W. Blom's essay argues that Grotius' biblical criticism was a distraction from his ‘real intellectual achievements’, those social and political theories founded on the study of natural law and written from a perspective ‘independent of any religious position’ (p. 73). Blom also argues more fruitfully that in the seventeenth century an impetus towards either toleration or comprehension of heterodox groups came from within the Dutch Reformed Church and was dictated by the logic of Calvinist theology. S.-J. Savonius-Wroth's essay on Locke, Le Clerc and Bayle gives a sense of how Remonstrant and Contra-Remonstrant approaches to toleration played out in a later Anglo-Dutch context. Both Blom and Savonius-Wroth militate against Jonathan Israel's account of toleration in Radical Enlightenment.

The inclusion of Israel's chapter which, in the editors' own words, ‘cuts across the editorial direction of this volume’ (p. 43) sharpens the focus of the collection and, by setting off the novelty of other contributions, makes clear their polemical force. Beginning with a statement that the ‘Radical Enlightenment’ was ‘secular, anti-religious and atheistic’ (p. 181), Israel argues that in the seventeenth-century Dutch Collegiants combined a version of Socinianism with Spinozism. In keeping with Israel's view of the long reach of Spinoza's thought, he concludes by identifying the influence of this particular Dutch anti-Trinitarian heterodoxy on a ‘radical’ strand of English Unitarianism. Similarly, Justin Champion's essay reiterates a familiar approach to the relationship between heterodoxy and secularisation. According to Champion, Hobbes presented in Leviathan a political and natural analysis of religion that underpinned anticlericalism and later accounts of priestcraft that explicitly attacked religion. Hobbes's own heterodoxy is accounted ‘radical’ and ‘enlightened’. One subtle point in Champion's argument is his claim that Hobbes's treatment of the relationship between words and ideas is designed to show that all theological ideas are expressions of opinion rather than God's truth. Space may have prevented Champion from explaining how this differed from conventional criticism of the particular methods of Aristotelian scholastic theology.

The main leg-work of reconstructing with subtlety and sophistication the consequences of heterodox thought is done by Richard Serjeantson, William Poole and Sarah Mortimer in essays on Hume, Isaac Vossius and Hooke and Grotius. Mortimer's excellent essay on Grotius demonstrates that Socinian theology ‘occasioned some important and unusual reflections upon justice and on natural rights and liberty’ (p. 90). She argues that Socinus set the terms of a debate about the possibility and necessity of the Satisfaction and that these terms were drawn from jurisprudence and moral philosophy. When Grotius responded to Socinus’ theology, he did so in the same language, and when Johan Crell responded in turn to Grotius and Socinus, he used the same intellectual framework. Thus Mortimer contends that the Socinians, in converse with Grotius, were founders of a new way of thinking about natural rights, and that they should be recognised as theorists of civil society. The introduction makes clear the methodological significance of Mortimer's contribution, and it is hard to fault her on the execution.

The introduction could have brought into slightly sharper focus the significance of essays by Poole and Serjeantson in demonstrating that historians of the early Enlightenment must take seriously the history of scholarship. Poole's chapter on ‘Heterodoxy and sinology’ assesses Protestant responses to the problems of Chinese religion, language and history, placing Isaac Vossius' sinophilia alongside that of various members of the Royal Society. The chapter demonstrates that heterodox ideas were at times deployed in the service of orthodox conclusions. Vossius' praise of Chinese learning was, in fact, an argument for the preservation in the west of the oldest available scholarly traditions. For Vossius it is not an eastern, non-Christian culture that is triumphant, but antiquity. Similarly, Chinese history does not challenge the biblical chronology, but supports Vossius' argument in favour of the longer chronology of the Septuagint. Ultimately, Poole demonstrates that Vossius' praise of Chinese culture does not evidence his being a ‘libertine’ (as he has been called). Indeed, Vossius avoided a touchy topic for sinologists, namely the relationship of Chinese religion to natural religion. Instead, Poole shows that the study of Chinese culture bore as heavily on questions about the history of language, the relative merits of ancient and modern poetry, and the study of medicine. Thus the chapter deftly illustrates the editors' central argument that heterodox theological ideas were inseparable from other problems in literary and intellectual culture.

Richard Serjeantson's contribution reconstructs the ways in which orthodox and heterodox thinkers had used sacred history and the history of idolatry to approach the problem of natural religion. First he surveys the ways in which historical scholarship had been used to argue for the Hebraic (and so revealed) origin of pagan wisdom, alongside another strand of apologetic scholarship which held that God had accommodated the Jewish revelation to Egyptian rites. Secondly, Serjeantson argues that freethinkers had exploited this diversity of opinion to argue that reason had proven sufficient for pagans' discovery of certain truths about God. Accordingly, deism was not ‘an exclusively philosophical phenomenon’ (p. 279), but relied on works of historical erudition. The third part of the essay argues that Hume rejected this historical reasoning about the value of reason in religion. Serjeantson thus shows that although diversity of theological opinion did influence movements such as deism, its reach into later periods of enlightenment should not be taken for granted. This treatment of freethinking is complemented by the last essay in the collection in which Brian Young argues, using the example of Conyers Middleton, that the gap between freethinking and rational Christianity was sometimes a narrow one.

The editors' clarity of vision has allowed them to marshal an impressive breadth of material. The variety of approaches taken by the volume's contributors sharpens the polemical edge of the editors' methodological statements. I can only echo their call that the study of heterodoxy and the early Enlightenment be moved in the directions that they begin to map.