In this original and learned book, Sara Ritchey highlights what she calls the ‘doctrine of re-creation’. According to Ritchey's broadest description, the doctrine entails a perception that the world was remade through the Incarnation such that, for ‘those trained to see’, God is perceptible in the natural world (p. 3). Although current scholarship neglects and misunderstands this doctrine, Ritchey's aim here is to show how a proper understanding can yield new thinking about such concepts as ‘nature’, ‘affective piety’ and ‘incarnation’ in medieval Christian thought (pp. 2–3). The ‘holy matter’ of the title refers not to objects or images but to natural phenomena like ‘grass, trees, fruits, flowers, [and] bodies’ that could ‘mediate’ the divine presence once cleansed of the taint of Adam's sin (pp. 3 n. 4, 12). This mediation goes beyond patristic understandings of the material world as ‘reflecting’ or ‘representing’ God; the theologians, mystics and spiritual writers whom she examines saw the ‘book of nature … as a manifestation of divinity’ (p. 17). However, to experience the divine in re-created matter involved human efforts; spiritual directors designed liturgies, prayers, images, religious rules, architecture and gardens for this purpose. The texts supporting these endeavours are the focus of Ritchey's analysis. Beginning with the twelfth-century Speculum virginum, she proceeds chronologically through ‘moments’ in devotional history in order to show how those schooled in the doctrine of re-creation remade their world. Thus, for example, the nuns under Hildegard of Bingen's care shared in God's creative power: by performing the liturgy, they sang God's materiality into being (p. 77). Clare of Assisi's experience of material poverty ‘made Christ present in the cloister’ (p. 103), while St Francis's performance of the mass over the staged nativity at Greccio allowed him to witness the ‘physical elements of the created world bending to reflect’ God's presence (p. 131). Given the participatory role in re-creation that Ritchey ascribes to her subjects, one wishes that she had engaged more with the problems raised by what seems a subordination of the divine to human effort. A central theme that she does treat is the slipperiness of language and metaphor and while there are ample citations, there are also times, as in her description of St Francis's performing the mass as ‘goading God into matter’ (p. 131), where I wish she had provided the direct quotation behind her interpretation. Nevertheless, the overall impact of this beautifully illustrated volume is as a thought-provoking complement to our understanding of late medieval spirituality and materiality.