Although a minor figure, Valentine Greatrakes, the Anglo-Irish faith healer, is a familiar figure to historians of science specializing in the Restoration period. Feted in his own day by contemporaries who saw the opportunity to use him as a perfect exemplar, or even embodiment, of their own religious and political aims, he has been used by recent historians to support their own claims about the nature of life and times in the Restoration. But just as Greatrakes was a controversial figure in his own day – not everybody saw him as a symbol of, much less a force for, moral regeneration – historians have interpreted his significance in differing ways. Here, in what will surely come to be seen as the definitive treatment of ‘the Irish stroker’, Peter Elmer now offers a highly judicious account based on meticulous scholarship. Resisting the temptation to jump to unsubstantiated conclusions, Elmer's account is always careful and well balanced, and offers an analysis which is nuanced and entirely persuasive.

Greatrakes has achieved a place in recent historiography of science thanks to the interest shown in him by Robert Boyle, and other more peripheral thinkers associated with the ‘new philosophy’, such as the Cambridge Platonist Henry More, and minor members of the Royal Society, such as John Beale and Joseph Glanvill. But Elmer's book is by no means focused entirely on this aspect of Greatrakes's brief period of fame in the early months of 1666. Indeed, readers of this journal might be disappointed that Elmer does not provide a systematic reassessment of the ways in which participants in the new philosophies reacted to this seemingly successful wonder-worker. We learn that Robert Boyle remained sceptical of Greatrakes, but there is no real attempt to explain Boyle's response. But, given that one of the best sections in the book (pp. 143–153) is concerned with the minor virtuoso John Beale, and his attitude to Greatrakes, it may simply be that comparable historical evidence to judge Boyle's position does not exist. Certainly Boyle was far more circumspect about exploiting Greatrakes's supposed abilities for his own religious ends than was Henry More, who never let an opportunity to show the inadequacy of the mechanical philosophy, however dubious, pass him by.

Readers of this journal may also regret that Elmer did not spend more time discussing the reactions of physicians to this layman achieving cures where they could not. He tells us that Greatrakes won many testimonials from physicians, but the majority seem to have been reformist physicians who advocated the new chemical medicine against traditional Galenism. It is easy to see in general terms why this might have been, but there is no specific discussion of individual physicians, or even a wider discussion of how Greatrakes might have been used in debates about medicine as a profession. But again, this may simply be due to lack of evidence. Certainly, Elmer tells us of an attack on Greatrakes by an anonymous orthodox physician, but he cannot go into details because the pamphlet in question is ‘sadly no longer extant’ (p. 83). We are told that Lord Conway, who evidently witnessed hundreds of cures achieved by Greatrakes, attributed this to his having ‘a sanative virtue and a natural efficiency’ (p. 78; see also p. 87). Given that the alternative to such naturalistic assumptions was inevitably more controversial suggestions that he was a conduit in some way for divine power, it is odd that such debates do not figure more prominently in Elmer's account. Indeed, Elmer acknowledges early on that previous interest in Greatrakes among historians of science has been based in early modern attempts to say ‘where the boundary between natural and supernatural phenomena might lie’ (p. 2), and yet he refers to Greatrakes throughout as a ‘miracle healer’ without ever fully discussing the thorny issue of miracles and their crucial significance in Counter-Reformation Europe (but see p. 16). This issue is not even discussed in the otherwise excellent chapter on ‘Healing, witchcraft, and the body politic in Restoration Britain’ (pp. 111–153).

But Elmer's concern is not primarily with Greatrakes's significance for the history of science, and we should not take him to task for failing to cater fully to our interests. Elmer's rich and highly nuanced account seeks to show the political and religious context of which Greatrakes was a part – and which made Greatrakes what he (albeit briefly) became. Elmer shows here the importance of the impulse towards comprehension and eirenicism as a way of settling political and religious discord. This was an impulse shared by many groups, including latitudinarian Anglicans, presbyterians and even radical sects like the Muggletonians, and it was thinkers like these who contrived to make Greatrakes famous. Elmer convincingly shows how Greatrakes's seeming success as a faith healer not only could be used to combat the widely perceived threat of atheism, but also could be used, by some at least, to promote religious reconciliation and political unity.