Jacques Le Goff once referred to the early Middle Ages as ‘a society of frustrated dreamers’ (‘une société de réveurs frustrés’) because it was a time, he argued, when Christian authorities stripped the common people of the ability to discern the value and meaning of their dreams. This study by Jesse Keskiaho challenges Le Goff's crude caricature of the period by examining the ways in which early medieval readers – primarily monks and clerics, but also a few laypeople – read and understood patristic texts related to the Christian understanding of dreams and visions, in particular Augustine's treatise On the care of the dead (De cura pro mortuis gerenda) and Gregory the Great's Dialogues (Dialogi). At the heart of this book is an important methodological agenda: early medieval readers usually encountered the ideas of patristic authors second or third hand, mediated by later compilers and often accompanied by marginal notes and commentary. This only becomes apparent when scholars, like Keskiaho, deal directly with the manuscript evidence. To take one example, only seven manuscript copies of Augustine's On the care of the dead are known from the first millennium, but selections from it circulated much more widely in compilations like Eugippius of Lucullanum's widely read sixth-century collection of Augustinian excerpts (Excerpta), which survives in seventeen copies dating before the year 1000. Carolingian compilers ‘cut and paste’ Eugippius’ work in turn, a process that Lynda Coons has called ‘bricolage’. As a result, most early medieval readers encountered Augustine's (and Gregory's) ideas far removed from their original presentation. Keskiaho argues convincingly that repeated redactions of the work of patristic authorities on dreams and visions shows a sustained and often creative interest in the topic throughout the early Middle Ages. Moreover, the ‘cutting and pasting’ of these texts for Carolingian audiences provided compilers with the occasion to simplify difficult concepts and eliminate troubling ambiguities in patristic works. The repackaging of equivocal opinions as binding maxims in the early Middle Ages is, Keskiaho claims, an important and overlooked aspect of what made these authors authoritative in the first place. Unfortunately, there are some flaws in the execution of this innovative study. Following an introduction, the book comprises three very long and unwieldy chapters on attitudes to visions in early medieval hagiography (chapter i), the reception of ideas about the nature of dreams in the works of Augustine and Gregory the Great cited above (chapter ii), and the reception of Augustine's theory of vision as presented in his literal commentary on Genesis, De Genesi ad litteram (chapter iii). A firmer editorial hand could have made the chapters more incisive and less repetitive, while improving the sometimes stilted prose. A very useful appendix (‘The pre-tenth-century manuscripts of the main works discussed’) rounds out the volume.