This is an intriguing, well-researched and at times poignant study of an epic rupture within the Puritan fellowship. Tim Cooper is interested in the fortunes of that fellowship broadly considered, but here he approaches it via the careers and predilections of two of its leading statesmen and apologists. It can be taken as a platitude to say that things got ugly and personal between Owen and Baxter, but this book conveys us to the occasion and the dynamics of their clash, and to the ‘vast common ground’ on which it was enacted (p. 177). Why, given that they held so much in common, did each range, and go on ranging, his sulphurous tongue against the other? Was there, indeed, a strong likelihood that their relations would sour? These are questions that give rise to hypothetical answers, and the difficulty of the task, as Cooper makes clear, is redoubled by the elusiveness of Owen. Baxter was compulsively self-revealing, but Owen's is a fugitive presence in the historical record. Cooper does well to put life into the almost bloodless voice of Owen the theologian and to acquire a sense of the personal being throbbing within the politician and the university administrator. Might the embitterment have been avoided? Cooper seems to straddle himself between ‘no’ and ‘maybe’. Certainly, he is dealing with combustible raw materials. Addicted to ‘telling men the error of their ways’ (p. 126), Baxter relished a controversy, and Cooper has dug far enough into the residues of Owen's temperament to find an irritable and even nettlesome individual, a man proud and ambitious, and given at times to railing and recrimination. So extreme were the differences in their experience and so broad were the commonalities of their religion that Cooper struggles to avoid being pricked by the thorn of his project. When he turns to matters that set his subjects apart – their processing of civil war, their objectives, motivations and operational modes – the road to conflict seems clear and straight; Cooper even speaks of ‘inevitability’, of the conflict's being ‘ensured’ by precipitating circumstances, of a collision ‘waiting to happen’ (pp. 54, 101–2, 184, 195, 284). Less teleological is Cooper's language when he addresses shared mindset – Owen and Baxter's honouring of a common Calvinist heritage (for all their relative lack of particular interest in Calvin himself). And the apprehension of a disaster in the wings all but dissipates when minds are shown applying themselves to the practical business of doing theology. The disagreement, at its origin, was seasoned with the idiom of concurrence and forbearance. But what began with tentative and measured speech soon escalated into mutual provocation. Yet, there might have been no feud had a correspondent not asked Baxter to comment on a few pages of Owen's Death of death (ch. iii). And so, triggered by the accident of a third-party enquiry, there commenced a consequential brotherly ruction freighted by lumpy ingredients of experience, learning, aspiration and sensibility. Cooper has refreshingly reconsidered a pair of prickly churchmen; would, though, that his index had been a better match for his text.