Robert Baillie often emerges in existing historiography as a two-dimensional caricature, and a somewhat inconsistent one at that. He is generally portrayed as a leading Covenanter propagandist in the late 1630s and 1640s, who nevertheless remained loyal to Charles i and who later welcomed the restoration of Charles ii in 1660. Part Presbyterian polemicist and part time-server, the received view of Baillie lacks coherence and defies categorisation. Alexander D. Campbell's excellent new book transforms this situation by bringing Baillie alive and offering a highly persuasive and three-dimensional portrait. Campbell argues that accounts of mid seventeenth-century Scotland have been bedevilled by a Manichean distinction between ‘Presbyterians’ and ‘episcopalians’. Campbell shows how for many, including Baillie, this divide was a porous one, which in turn helps to explain the breadth, diversity and ultimate instability of the Covenanter movement. Baillie was a judicious scholar who liked to reflect before reaching a settled position on theological and ecclesiological issues, and although a controversialist of European repute, he was temperamentally averse to confrontation and habitually sought to promote conciliation. He hoped above all to maintain the unity of the Scottish Church, and throughout his career he reserved his greatest hostility for Roman Catholics on the one hand and for Congregationalists and separatists on the other. Baillie regarded presbytery and monarchy as ‘mutually supporting institutions’ and believed that ‘if both were established and governed according to the fundamental laws of the kingdom, they would not come into conflict’ (p. 59). He thus epitomised a strand of ‘Presbyterian royalism’ (pp. 60, 78) which naturally tended towards passive obedience to the Crown. Although he accepted that armed resistance to a monarch who breached the fundamental laws was permissible in extremis to defend Scotland's laws and religion, he insisted that this could only be undertaken by the whole representative body of the realm in parliament. Just as he believed that presbytery and monarchy could operate in symbiosis, so Baillie's ‘support for a Presbyterian polity accommodated aspects of episcopalianism to an extent that has hitherto been underestimated’ (p. 87). His ‘attitude to episcopacy was more nuanced and less critical than has hitherto been assumed’, and he was concerned above all to preserve ‘a unified, national church that could combat both antichristian tyranny and sectarian anarchy’ (p. 90). Baillie never denounced episcopacy in general, but he abhorred the Laudian assertion that it was a distinct order that existed by divine right. Rather, he seems to have believed in a form of primitive episcopacy that had some affinity with that advocated in England by divines such as ‘Smectymnuus’. He remained committed to the idea of an inclusive national Church that embraced both the saved and the reprobate, a position that by the 1650s aligned him clearly with the ‘Resolutioners’ against the ‘Protestors’. Baillie was disturbed by the rise of congregationalism and sectarianism in Scotland and England during the later 1640s and 1650s, and he ‘and his fellow Resolutioners increasingly came to believe that the only hope for a satisfactory ecclesiastical settlement rested in Charles ii’s restoration’ (p. 112). Baillie's central vision was of a loosely defined confessional union between Reformed Protestants, governed by the authority of Scripture. He hated the Laudians for over-emphasising tradition at the expense of Scripture, and he hated the sectarians for disrupting the unity of the visible Church. This inevitably led him to be criticised by advocates of liberty of conscience like John Milton, who included Baillie among the ‘new forcers of conscience’ (p. 138). Throughout his career, it is possible to discern an underlying consistency in Baillie's attitudes. Campbell argues convincingly that ‘a desire for peace and unity animated most of Baillie's writings’, and that ‘in formulating his presbyterian vision, Baillie emphasised the importance of incorporating as many subjects in a kingdom into a unified national church as possible’ (pp. 143–4). This helps to explain his contrasting reactions to the various royal reforms of the Church during the early seventeenth century. Whereas Baillie could live with James vi & i’s Five Articles of Perth (1618), and indeed defended kneeling at communion, he regarded Charles i’s Scottish Prayer Book (1637) as ‘popish’ and ‘idolatrous’ (p. 146). He did not view all alterations to church worship in the same way, but rather tested each of them, through careful reading and reflection, against the authority of Scripture and in terms of their implications for Church unity. The act of kneeling at communion was not, in Baillie's eyes, idolatrous. By contrast, he felt that ‘evidence of crypto-popery seemed to be rife through the Prayer Book’, and that it ‘more closely approximated the Roman liturgy than the English Book of Common Prayer’ (pp. 162–3). He deplored the Laudian emphasis on the sacraments; instead, he asserted the crucial importance of the sermon, and he displayed ‘a particularly rigid, even obstinate, conception of Scripture's self-sufficiency’ (p. 174). Campbell's intellectual biography concludes with a fascinating chapter on Baillie's preservation of an extensive archive of his own letters and journals. This reflected his sense of the historic importance of the events through which he was living and his desire to preserve a body of materials relating to his own life that might one day be valuable for future scholars writing an account of the Covenanting movement. In so doing, Baillie also left behind resources that illuminate the extraordinary religious and intellectual vitality and ferment of mid seventeenth-century Scotland that enables us not only to understand better the complexities and subtleties of a figure such as Baillie, but also to appreciate that the remarkable achievements and creativity of the Scottish Enlightenment during the following century did not come out of nowhere. Campbell has produced a deeply researched and elegantly written study and he has succeeded admirably in his stated aim of demonstrating ‘contrary to entrenched opinion, that pre-Enlightenment Scotland gave rise to a richly variegated, cosmopolitan and dynamic nation of thinkers’ (p. 4).