One of the most exciting outcomes of the contextualist turn in the history of political ideas has been a better understanding of the practical concerns of political philosophers. But although this approach has done much to reveal the political commitments of early modern thinkers such as Machiavelli and Locke, the allegiance of Thomas Hobbes has proved to be much more resistant to contextual explanation. One common allegation leveled at the philosopher after the restoration of Charles II in 1660 was that his Leviathan (1651), perhaps the greatest work of political theory in English, was nothing more than an attempt to legitimize and promote the political and religious policies of Oliver Cromwell. It was a charge that appeared to be supported by Hobbes's relocation from France to republican England in the winter of 1651/2, a move represented by republicans and royalists as confirmation of Hobbes's disillusion with the royalist cause. It was a claim that Hobbes would later vigorously deny, arguing that his book had been designed to show how defeated royalists could legitimately compound for their estates, a loyalist move insofar as it would prevent further resources falling into the hands of the usurpers. Hobbes's loyalist alibi has complicated discussions of the character of his political allegiance ever since, but in this robustly argued study Jeffrey Collins seeks to reopen the question of Hobbes's political allegiance during the Interregnum period to argue that his Restoration opponents were effectively right about the audience and intention of Hobbes's masterpiece.

Collins makes this argument by focusing upon the philosopher's central preoccupation with religion. At the core of Hobbes's project, Collins argues, lay the super-Erastian ambition to subordinate religion to the state. The substantial claim of the book is that it was this ecclesiological agenda that ultimately determined Hobbes's political allegiance, causing him to break with the royalist cause and to align himself with the revolutionary republican regime and in particular with what Collins takes to be its central project: the establishment of an Erastian church settlement.

This account moves Hobbes into the perhaps unexpected company of religious radicals, a trajectory that owed much to a shared anticlerical agenda, but Collins is careful to distinguish Hobbes's version from that of the Reformation Protestants he would court in Leviathan. As a skeptical humanist Hobbes, following his classical pagan exemplars, took an instrumental view of religion as a tool of social control. His response to the subversive aspects of Christianity was an attempt to recast it as a civic religion that could be used to create order and obedience. Collins argues that the coincidence of this Machiavellian agenda with the increasingly Erastian direction of the English Revolution effectively brought Hobbes to endorse the cause of religious Independency and to see Cromwell (as early as 1650–51) as a sovereign capable of delivering a Hobbesian religious settlement.

Collins is very good at charting Hobbes's increasing preoccupation with church politics and in drawing attention to the strident Erastianism that became one of the dominant themes in Leviathan. But he also does much more than this, providing a thorough and persuasive account of the role of Erastianism more generally during the 1640s and 1650s, highlighting the ways that this cause constituted common ground between Hobbes and religious Independents, and also with the republicans who shared his Machiavellian religious instincts. That said, the argument becomes more problematic and the evidence a little strained when Collins attempts to portray Leviathan's occasional and ambiguous allusions to religious Independency as an uncomplicated endorsement of the Independent party and a future Cromwellian regime. Although it is true that Leviathan contained statements designed to appeal to religious Independents (among others), his ecclesiological prescriptions, like his constitutional suggestions, were carefully crafted not to exclude a variety of arrangements (with the unexceptional exception of Roman Catholicism), provided that they followed the logic of his theory of sovereignty. It could be argued (pace Collins) that the political uncertainty of the period of the book's composition in fact required Hobbes to avoid overidentification with one party or another if Leviathan's broader program of cultural transformation was to stand any chance of success. It is perhaps no accident that Hobbes's personal political commitments remain deliberately and frustratingly opaque when subjected to contextual analysis. In the end Hobbes was forced to return to England by his enemies at the court in exile, making the act of return, like the book itself, difficult to decode as an indicator of Hobbes's underlying political sympathies.

Collins's thesis is better suited to some of Hobbes's actions and statements in the mid-1650s when, under fire from Presbyterian and Episcopalian critics, Hobbes did allow his admirer Henry Stubbe to attempt a rapprochement between the philosopher and the Oxford Independent John Owen. But Stubbe's failure and Owen's justified suspicion of the Hobbesian project serve only to illustrate the differences between Hobbes and the Congregationalists, in spite of their overlapping interests in Erastian models of church government. It is undoubtedly true that Hobbes's ideas were much closer to those of his contemporaries than is usually supposed, and Jeffrey Collins has given us a better understanding of these sometimes carefully concealed connections. But whether these shared views necessarily reveal the personal political preferences of a philosopher and political survivor as prudent as Hobbes is far from clear.