Derek Hill's comparison of the inquisitorial manuals of Bernard Gui (1260–c.1330) and Nicholas Eymerich (1320–99) is based on his recent Birkbeck College doctoral thesis. It is a most welcome addition to the historical scholarship on inquisition, focusing on two specific inquisitors who worked in distinct social, religious and political contexts. Taking forwards Lucy Sackville's authoritative 2011 discussion of the wide range of thirteenth-century textual discussions of heresy, Hill's focus is in one sense more narrow – looking only at inquisitors’ handbooks – but he also contextualises his two main authors in a way that ought to stimulate further reflection on divergent experiences of inquisition, both among its personnel and its victims. Besides detailed accounts of Gui and Eymerich, Hill gives some space to comparison with the anonymous De officio inquisitionis (1320s, Italy) and Zanchino Ugolino's De hereticis tractatus aureus (c.1330, Italy), though this is relatively underdeveloped.

Bernard Gui was a Frenchman from Limoges, a Dominican friar who was first appointed as an inquisitor in 1307 at Toulouse. His Practica inquisitionis heretice pravitatis, completed in 1325, was, as its title suggests, a practical guide for inquisitors, based upon his long experience of running all aspects of a busy investigative operation. The Practica distinguished carefully between groups whom Gui – in common with thirteenth-century scholastic thought – believed to be quite distinct, particularly Cathars and Waldensians, but also newly defined heresies such as the beguines. It was, in Hill's words, ‘an insider's book’ written for his colleagues and successors in Languedoc. The Toulouse inquisition was financed by the French crown, but Gui was ambivalent about the reliability of local royal officials, and he emerges as a canny political operator. Although he used torture (but was relatively circumspect about it in his treatise) and was enthusiastic about the effects of lengthy periods of harsh imprisonment upon suspects’ willingness to confess, Gui is characterised here as a ‘humane’ and ‘cautious’ inquisitor. The contrasts with Nicholas Eymerich are very interesting. The Catalan Eymerich was, like Gui, a Dominican. He was first appointed as an inquisitor in 1358 in the kingdom of Aragon, where he enjoyed greater autonomy from secular rulers than had Gui, although this led to more dramatic clashes including his twice being expelled from the kingdom. Hill argues that these expulsions resulted from his uncompromising attitude to the role of inquisitor, and being unafraid to act in ways that disturbed the political balance. This came in his attacks on intellectuals such as Ramon Llull, and his expansive definition of magical practices. His Directorium inquisitorum was not just a practical handbook, but also a legal discussion of and theological justification for inquisition. Hill's assessment is that Eymerich was an ‘abrasive’ character driven by zeal, who ‘pushed the logic of his theological belief too far’.

As that quotation indicates, there is assessment and judgement of these two inquisitors in Hill's book, not just a comparison. This drives much of the discussion without being all that easy to pin down. In historiographical terms Hill takes a critical view of medieval jurisprudence and criminal procedure based on a view about what the law should do and how it should operate. His is not quite the view of Henry Ansgar Kelly, that inquisition was nefarious because it broke all protocols and safeguards of medieval canon law; nor is it quite Paul Strohm's view of ‘the trial as mousetrap’, designed to trick suspects into self-incrimination. Hill's view seems to be that although inquisitors were ‘bound by the law’ their actions were compromised by their obeisance to secular rulers (Bernard Gui) or their unconstrained zeal (Nicholas Eymerich). For him, this means that they always fell short of ‘modern standards’. However, the theoretical and empirical bases of Hill's frequent invocation of modern standards – of jurisprudence, police procedure, criminal trial procedure, imprisonment and coercion – is never articulated, which confuses the issue somewhat. It may be that he is drawing upon his own impressions of English common law, but these seem to be more hopeful than realistic; certainly he does not have in mind the experiences of suspects tried under UK anti-terror legislation, or the indefinite detention-without-trial and intimidating questioning used against unwelcome migrants. It may seem unfair to raise these points, since a critical examination of modern criminal justice is outside Hill's remit, but the trans-historical comparisons are frequently explicit in his book, and their fuzziness might lead to confusion. For instance, when Hill writes that Gui's selective recording of evidence and use of predetermined interrogatoria ‘would not have met modern standards’, the comparison is unwarranted. As an attempt to locate coercive institutional power firmly in the distant past, it has the effect of making medieval and early modern inquisition seem historically aberrant, explicable in terms of conditions and attitudes that no longer apply. Explaining medieval institutions in terms of a lack or deficiency places them at an early stage in a developmental model of progress, making it harder for us to see them as fully formed in their own right. At other times the insertion of modern comparisons is tacit or even unconscious: when Hill writes that ‘religious conformity was … necessary to maintain social cohesion, although it should not be imposed in such a way that it affected the social cohesion it was trying to create’, the reader may be unsure whether this is an extrapolation of Bernard Gui's views, or a normative and trans-historical authorial comment. There is certainly scope for further debate on these points, and Hill's book provides a welcome stimulus to both diachronic and synchronic comparison.