One of the hallmarks of recent scholarship on late medieval science and magic has been to situate these subjects within broader intellectual and cultural contexts (e.g., Ziegler, Medicine and Religion, c. 1300: The Case of Arnau de Vilanova [Oxford University Press, 1998]; DeVun, Prophecy, Alchemy, and the End of Time: John of Rupescissa in the Late Middle Ages [Columbia University Press, 2009]; Power, Roger Bacon and the Defence of Christendom [Cambridge University Press, 2012]). Continuing this trend, Zachary Matus posits that distinctively Franciscan approaches to nature and the End Times informed the alchemical writings of three Friars Minor in the later Middle Ages: Roger Bacon, Vitalis of Furno, and John of Rupescissa. At the same time, Matus plugs into the current scholarly interest in Christian materiality, arguing that his authors' sought-after alchemical elixir was no mere symbol but a physical agent whose effects could help to remake humans and the world as they should be. Finally, Matus insists that religious practice, as well as ideas, informed his subjects' approaches to alchemy.

Franciscans and the Elixir of Life proceeds in four large sections, framed by a brief introduction and conclusion. In the first chapter, Matus claims that Franciscans had a particular take on nature (or, more properly speaking, creation) and the material world. Beginning with a close reading of The Canticle of Brother Sun, Matus highlights Francis's own experience of God in nature, noting a similar emphasis on creation as manifestation of God in writings by the later Franciscans Bonaventure, Peter of John Olivi, and Nicholas of Lyra.

In chapter 2, Matus introduces his three case studies of Franciscans who wrote treatises about the elixir, an alchemical medicine that could “cure” and perfect the human body. Matus begins with a lucid explanation of Roger Bacon's elixir, which was designed to restore a perfect humoral balance missing since the expulsion from Eden. He demonstrates convincingly that this elixir was meant to produce bodies like those of the resurrected dead, as well as (so Bacon hoped) help to prepare non-believers to receive the Christian message. Second, Matus argues that Vitalis of Furno, discussing a medical composition called aqua ardens, studiously avoided subjects considered controversial by Franciscans at the time, particularly any overtly alchemical discussion of a medicine that nonetheless behaved a lot like the elixir. With John of Rupescissa, Matus stresses again the blending of scientific and religious goals, noting, as Leah DeVun also has done, that Rupescissa spoke of his elixir as the quintessence, a distillation of the substance that composed the heavens, and thus, literally, as “heaven on earth.”

Chapter 3 is devoted to the apocalyptic context against which these works were composed. Matus offers a helpful introduction to Franciscan apocalyptic ideas before turning to Bacon's own eschatology, particularly his sense that the study of scientia experimentalis could arm Christians with the weapons they needed to resist the oncoming onslaught of Antichrist, as well as to convert the heathens. Matus reads Vitalis's apocalypse commentary as a conservative backlash against the radical, Joachite-inspired apocalyptic of Peter of John Olivi. Still, according to Matus, despite the fact that Vitalis appears to disparage Plato and Aristotle, he did not reject the study of natural philosophy. With Rupescissa, Matus follows Robert Lerner's interpretation of the friar as influenced more by Olivi's Joachimism than by an adherence to the Spiritual Franciscan cause; like DeVun, Matus points out that Rupescissa intended his elixir to serve as a weapon in the battle against Antichrist, whose imminent arrival Rupescissa, too, envisioned.

Chapter 4 is the most ambitious and, ultimately, least tidy of the book's divisions. Here, Matus asserts that Franciscan alchemy should be viewed as a “subjunctive science,” capable, like ritual, of “producing the world as it should be” (101). He also delves into medieval suspicions about magical practice, ties between magic and miracles, the traditions of the Corpus Hermeticum, and charms that mingle devotional and magical aspects. The chapter also includes a fascinating treatment of John of Rupescissa's condemnation as “phantasticus” (delusional or mad), a term that, according to Matus, Rupescissa embraced and subversively deployed in later writings to defend his role as a prophet.

Matus's efforts to argue for a distinctively Franciscan approach to nature and, thus, to alchemy, while appealing, are not entirely successful, however. Indeed, the second case study, of Vitalis of Furno, fits somewhat awkwardly into the narrative. As Matus acknowledges (5, 188), Vitalis himself may not have authored the two treatises analyzed here. The book also suffers from a lack of engagement with several recent studies. Most glaringly, Matus does not mention Amanda Power's Roger Bacon and the Defence of Christendom (Cambridge University Press, 2012), which also proposed that Bacon promoted “experimental science,” including alchemy, in order to produce remedies aimed at countering the magical arts of Antichrist and converting the heathens. Similarly, Matus's work shares some themes with Sara Ritchey's Holy Matter: Changing Perceptions of the Material World in Late Medieval Christianity (Cornell University Press, 2014), also not cited here. Since Ritchey explores an interest in creation among a wide variety of religious thinkers (many of whom were not Franciscans), her work poses an implicit challenge to Matus's assertion that an engagement with the material world was a uniquely Franciscan trait. Matus's discussion of Christ's revelation of a miraculous cure to “three good brothers” (112–113) shows no awareness of the history of this widely circulated charm, which has been known to folklorists and historians since at least the early twentieth century, and which is also discussed in Ritchey's book. (This lacuna, perhaps, explains Matus's erroneous claim that the “three good brothers” of the text were in fact Franciscans.) There are also a few copy-editing/proofreading errors, the most egregious being the disappearance of note 81 from chapter 1, signaled in the text but missing in the endnotes.

Still, the book makes a clear contribution to a number of scholarly conversations not simply about the history of alchemy but also regarding the “material turn” in the study of medieval religiosity. The monograph also showcases Matus's ability to work across disciplinary boundaries (as, indeed, his subjects did) and to present complicated ideas in clear, accessible, and vivid prose.