As Bernard McGinn noted many years ago, St. Bonaventure of Bagnoregio’s Itinerarium mentis in Deum is one of the ‘purest gems’ of late medieval spirituality. Theologically rich and spiritually captivating, the Itinerarium is undoubtedly one of Bonaventure’s best-known works. Yet for all its celebrity, and the various lucid translations now available, the Itinerarium is a challenging read, especially for those new to medieval thought. As even a cursory glance at Bonaventure’s text reveals, it contains a by no means insignificant amount of abstract theological reflection, some of which is difficult to penetrate, even for specialists. Thus, in chapter five, Bonaventure offers a detailed meditation on God’s identity qua eternal and infinite being, while in chapter six, he explains how the Trinity is grounded in the self-diffusive nature of the Good. Unlike the earlier Lignum vitae and the near contemporary De perfectione vitae ad sorores, Bonaventure thus appears to have written the Itinerarium with a theologically trained audience in mind. Those encountering Bonaventure’s text for the first time today can thus be forgiven for feeling slightly overwhelmed by it or for being tempted to skip over certain chapters. Given the Itinerarium’s fame, and the fact that it often serves as the first point of contact with Bonaventure that many undergraduates have today, it is striking that no companion piece or scholarly commentary on the text has emerged, at least in the Anglophone world. Randall Smith’s recent Bonaventure’s Journey of the Soul into God: Context and Commentary (Cambridge: CUP, 2025) rectifies something of this lacuna.

In his impressive, well-written monograph, Smith offers a detailed but accessible discussion of the Itinerarium. He introduces the reader to the text’s basic structure and themes, while also elucidating some of its more complex theological discourses and how these fit within its overall spiritual thrust. Smith’s text, however, is no mere work of exegesis. Instead, it presents us with a new way of reading the text as a whole. Key here is Smith’s background in medieval sermon studies, specifically the sermo modernus style of preaching associated with the medieval university. Smith’s central thesis is that while the Itinerarium itself may not be a sermon, Bonaventure nonetheless ‘employed the pedagogical and exegetical method of the sermo modernus style of preaching’ in its construction. Smith notes that while scholars have made much, and rightly so, of the fact that Bonaventure bases the Itinerarium’s structure on the six wings of the crucified seraphim which appeared to St. Francis on Mt. Laverna in 1224, closer inspection reveals that other, equally important, structures can be detected in the text. Key here, he contends, is the fact that each chapter appropriates something of the distinctive threefold structure of a sermo modernus – namely, thema, divisio, and dilatatio. Of particular importance for Bonaventure are the divisio, which serves to outline the different parts of the scriptural thema, and the dilatatio, which expands these parts. Once viewed through this lens, Smith argues, convincingly it must be said, that we find it ‘much easier’ to engage the Itinerarium’s chapters and appreciate their ‘particular elegance and genius’.

Following a comprehensive introduction, Smith’s monograph proceeds in two parts. Part I consists of seven chapters. These offer a detailed account of the Itinerarium’s background and context, as well as how its various chapters employ the sermo modernus method. Particularly instructive is Smith’s account in chapter one of how Bonaventure stood at the heart of the ‘homiletic revolution’, which occurred during the mid-thirteenth century, and his discussion in chapters two and three of Bonaventure’s use of divisiones to structure his text. Also valuable is Smith’s discussion in chapter six of how Bonaventure’s use of visual imagery to structure his text finds a precursor within Victorine spirituality yet also contains several novel traits. These, Smith demonstrates, are to be retraced back to Bonaventure’s ‘training in sermo modernus style preaching’. Part II of Smith’s text offers a comprehensive commentary on the Itinerarium’s different chapters, taking as its lead Bonaventure’s own structuring of the text according to the seraphim’s three pairs of wings. Here, Smith drills down into some of the core themes of Bonaventure’s thinking while placing them in relation to his chief interlocutors, including, amongst others, Pseudo-Dionysius, Richard of St. Victor, and Thomas Gallus. A timely study, Smith’s book is one from which students and scholars alike will benefit. One minor criticism is that parts of Smith’s text, particularly some of the chapters in Part I, could perhaps have been edited slightly without detracting from their focus and argument. Nonetheless, Smith’s study is a very fine piece of work which will surely help to further our understanding of the Itinerarium mentis in Deum, while also making this important Franciscan text more accessible to those new to the study of St. Bonaventure.