Scott Bruce's general theme is the role of silence within the medieval monastic regime. Periods of silence, valuable for the purposes of reflection and as a form of detachment from the external world, had long played an important part in monastic life. In Carolingian monasteries they became dominant to such an extent that abbots came to set aside specific areas of the house and specific periods of the day for conversation. Even secular rulers, such as Louis the Pious, could be praised for their complete detachment in the face of the traditional courtly amusements of jesters and actors. But it was the Cluniac order from the early tenth century onwards which heightened and maximised traditional doctrines of monastic silence to the point where community life would simply have become impossible without the adoption and growth of a form of sign language. And it is the nature, use and spread of this sign language which provides the specific focus for Bruce's monograph. The sign language of Cluny undoubtedly developed at a rather earlier date but it first emerges in detailed form only in the late eleventh century. Unfortunately the surviving version is partial in that it represents only the form specifically used by the novices; that is, it has a truncated vocabulary of little more than a hundred signs, concentrated on the three everyday areas of food, clothing and the divine office. It is clear that the choir monks deployed a much more extensive repertoire of signs, but for this it is necessary to go to the various derivatives of the Cluniac system which are to be found in detail at Fleury, at Christ Church, Canterbury, and at the Black Forest abbey of Hirsau. In particular, the Hirsau sign lexicon is much elaborated, containing 359 signs compared with the mere 118 surviving from Cluny. In part this almost certainly reflects to some degree the fuller sign vocabulary deployed by the choir monks at Cluny. But these derivatives from Cluny often also contain revealing modifications to suit local circumstances. Some are trivial. For example, at Fleury a sign representing herrings came to be included, a tacit acknowledgement of the fact that the fish formed a regular part of the diet in this particular house but was probably not familiar at Cluny. Some are much more revealing. The adoption at Canterbury of a version, derived from Fleury, of the Cluniac sign language was probably an aspect of the monastic reform movement associated particularly with King Edgar. Hence it is appropriate and revealing that the Canterbury version should include new signs for the king and the queen, in acknowledgement of the role of the monarchy in stimulating monastic revival in England. Even more striking is the fact that the Canterbury sign lexicon was composed in the vernacular. The same King Edgar had himself sought an Anglo-Saxon text of the Rule of St Benedict, and vernacular translations formed an integral part of the whole movement for monastic reform in Anglo-Saxon England. From this point of view the Canterbury sign language is emblematic. Indeed it is one of the most valuable features of Bruce's study that he is sensitive to many aspects of the context of this language. For, as he stresses, language it was not; at least not in the sense of a modern sign language designed to enable the deaf to ‘hear’. The Cluniac sign language and its descendents were specifically designed to avoid idle, worldly chatter within the cloister. It would have nullified this purpose if the sign language had merely reproduced conventional talk but phrased it within a different medium. For this reason the sign language was specifically designed to make normal conversation impossible; indeed it existed almost entirely to enable the life of the community to be conducted effectively but without normal conversation, a structure of communication limited to practicalities. It was ‘a purposefully disabled language’. Hence in its original Cluniac form the vocabulary consisted almost entirely of nouns, or objects; it contained no pronouns, prepositions or conjunctions. It was strikingly symptomatic of monastic poverty in that it included almost no possessive adjectives, one of the few exceptions being a sign for ‘my’ sins. Rather, it was merely a vehicle for the articulation of simple nominal concepts. In all of these respects the language exemplified monastic imperatives. But Bruce is also alert to more mundane contextual implications. The Cluniac model developed at a time when the monastery itself was expanding rapidly. Hence it was particularly crucial in providing a means of communication for monks who not only knew no Latin but might not even possess a shared vernacular. But over and above such practical considerations the sign language created ‘a spiritual speech community’, engendering a sense of solidarity and separateness within the house. From this point of view it became an important element in fostering Cluniac self-regard. Bruce provides lexicons for the sign languages of Cluny, Fleury, Canterbury and Hirsau but these lexicons are simply verbal; that is, they list the Latin words which are signified alongside their English translation. Only in the case of Cluny, in an appendix, are we supplied with a list of the actual signs themselves, the manual actions. By and large these represented ‘an imagination of resemblance’ where the signs represented a ‘visual experience’ of the object in question. So bread took its sign from its own roundness, porridge from a gesture of stirring, and a priest from his tonsure. Occasionally a sign strays from such objectivity and might itself convey a critical judgement. The Cluniac monks were instructed to refer to a work of pagan literature by touching their ears with their fingers ‘just as a dog usually does when scratching with his foot, because a person without faith deserves to be compared with such an animal’. But such expressions of opinion were unusual, and in general the signs themselves were as functional as the matters that they represented. On such matters Bruce is an informative and insightful guide. It is only when he steps outside his chosen field that, as with so many converted dissertations, his touch becomes less sure. It is a trivial matter to remark that the Somerset Charterhouse of Witham was in Kent, or to describe this priory as an abbey – although the appellation of priory was fundamental to the Carthusian ethos and even the mighty royal foundation of Sheen sought nothing more. More disconcerting is his apparent view that the matter of the originality and sources of the Rule of St Benedict has ‘inspired some debate in recent years’. But it is his association of Cluniac monastic silence with the angelic order that arouses most doubt, although it forms an essential prelude to his more detailed study that follows. For the Cluniac monks a crucial expression of ‘angelic mimesis’ was ‘the cultivation of a profound and reverential silence’. They developed a new ascetic ideology which ‘married the glorification of silence to the ideal of an angelic life realized in mortal bodies’. From this everything else flowed. Yet such an angelic theology seems quite at odds with the scriptural portrayal of angels as messengers, where they are often so far removed from taciturnity as to appear almost garrulous. And this role cannot be dismissed as merely the creation of modern ‘narcissistic preoccupations’. Such contradictions cry out for a deeper and more extended elucidation. And it is this rather meagre account of the essential theological basis for the evolution of the sign language that somewhat impairs an otherwise instructive and perceptive study.