Ever since Gaunilo first responded to its argument, St Anselm's Proslogion has been read as mainly presenting a rational argument about God's existence and nature, one that would be convincing to a nonbeliever. John Bayer's book, adapted from his dissertation at the Pontifical Gregorian University, is a contribution to the minority tradition dissenting from this ‘rationalistic’ view. Bayer, a Cistercian monk, hopes to show that the chapters of the Proslogion that seem most rationalistic (such as his proof in chapter ii) and the chapters that seem most mystical (such as the prayer in chapter i) actually are not in tension. The Proslogion, and mysticism and reason more broadly, can be seen to be unified by Anselm's vocation as a monk and by the monastic theological tradition which he inherits.

Chapter i sees Bayer rather quickly dismiss the dominant rationalist position as mistaken because it depends on ‘an abstract or conceptual definition of God’ (p. 37), rather than the ‘subjective’ ‘human-linguistic experience’ that characterised Anselm's own encounter with God as a Christian and a monk. He justifies this dismissive approach by suggesting that the rationalists (going back to Gaunilo and Aquinas, presumably) neglect ‘the role played by intellectus [understanding] in medieval rationality’ (p. 38), a neglect that Bayer hopes to remedy.

The second chapter is an entirely novel (and to my mind quite successful) attempt to reconstruct Anselm's general approach to spirituality and spiritual direction from his letters and from neglected works such as the Memorials. Sally Vaughn and others have noted that Anselm's extensive collection of letters cries out for just this sort of focused study, and Bayer's own insights into monasticism and the monastic intellectual tradition sparkle throughout his treatment. Bayer notes that his chapter ii is ‘the first extensive and systematic exposition of [Anselm's] spirituality in English’ (pp. 66–7), and it should serve as an essential starting point for future research. Bayer makes a convincing case that Anselm holds a view of holiness that is consistent across states of life – laity, as well as religious, have to arrive at the same spiritual goal of loving God above all other things.

The rest of the book is a much less successful attempt to understand Anselm's views about reason, especially in his controversy with Roscelin and in his early innovative works the Monologion and the Proslogion. As noted above, Bayer thinks that the rationalistic tradition fails to understand medieval rationality. But Bayer's own analysis reveals a profound unfamiliarity with the early medieval tradition of logic, the logica vetus, which leads him to misunderstand fundamental aspects of the background that both Anselm and his educated readers could assume. For instance, Bayer spends nearly forty pages discussing the straightforward point that in order to avoid the fallacy of equivocation, an argument must not just contain the same written words, but those words must signify the same concepts. He believes this is a major contribution of Anselm's dialogue De grammatico (p. 185), rather than a familiar consequence of Aristotle's ‘semantic triangle’, the idea that spoken words signify things by means of concepts.

Bayer's unfamiliarity with the logica vetus also weakens a central argument of the book, that Anselm's very logic (what Bayer confusingly calls his ‘grammar’) is spiritual and thus leads one to God. The argument is based on an equivocation in the meaning of the word ‘spiritual’: a concept can be said to be ‘spiritual’ in the sense that it is a being of reason or a real change in an immaterial intellect, rather than something physical like a change in brain states. He then argues that because concepts are spiritual, they lead one to holiness, to know God and to love him. In the first claim, the word spiritual means ‘immaterial’; in the second, it means ‘concerned with holiness’. The equivocation can be illustrated by the fact that someone thinking about Satan has a concept that is spiritual in the first sense, without it being spiritual in the second sense of leading the heart towards God. Bayer expresses pious amazement that Anselm's very notion of thinking is so spiritual, when Anselm is simply describing a general (and commonly held) theory of how people think about anything.

In place of the logica vetus, Bayer tries to interpret Anselm's writings using John Henry Newman's categories of real and notional apprehension, assimilating Anselm's idea of understanding in his slogan ‘faith seeking understanding’ to what Newman calls real apprehension. Bayer seems drawn to Newman's framework because Anselm very clearly wants his conclusions to move his readers to know and love God, and Newman's idea of real apprehension is also about how ideas move one to the act of believing. Bayer argues that if an argument persuades someone, it cannot be because of its concepts, but only because of that person's own experiences and subjective intuitions. This confuses speculative and practical reason – I can be persuaded that something is true and yet not consequently change my life. As Gyula Klima, one of the world's leading experts in medieval semantics, showed in a classic article, Anselm's Proslogion argument can be successful at the merely conceptual level, building up a store of concepts and showing the connections between them so that one cannot hold onto one's own important concepts without also holding that God must exist. Klima shows how the ‘abstract’ formula of the Proslogion is able to lead someone to form the necessary concepts in his own mind, at which point Anselm's argument could lead him to conclude that God exists. In contrast, Bayer comes close to suggesting that only Anselm's monastic brothers could truly understand the Proslogion formula, because only they have the experiences that could lead them to grasp Anselm's meaning with real apprehension. One obvious problem with Bayer's proposed interpretation is that Anselm addresses the argument to an atheist who does not share his monasticism; arguably, Klima's interpretation is closer to the text.

Because the elements of Bayer's reading are confused, the whole of the argument is unsuccessful. But the question of how to reconcile these parts of the Proslogion is a good one.

There is an argument that the right way to read the Proslogion is as a rational argument whose mystical passages were intended to facilitate its reception in a non-rationalistic age. Giles Gasper and Samu Niskanen have recently called attention to the fact that Anselm originally published the Proslogion anonymously, and only after it had been praised by the papal legate Hugh did he announce his authorship. Once assured of the legate's support for his work, Anselm added several elements to the final version that arguably emphasise the work's rationalism – the preface where he mentions the formula as central to the work, the chapter headings which separate out the argument, the Sumptum ex eodum libello (a summary of the argument of 2–4 which leaves out the mystical parts), and the debate with Gaunilo (which treats the argument of chapters ii–iv in isolation). Bayer's reading would have had a stronger case if Anselm had left alone the initial text; the additions that Anselm made after he received the support and protection of the papal legate emphasise the ‘rationalistic’ parts of the text. In other words, Bayer's reading of the Proslogion as a typical product of monastic theology would have been the intended reading of the preliminary anonymous text, while the ‘rationalistic’ reading that Bayer wants to argue against might have been Anselm's intended reading of the finished product. Eadmer writes that Anselm's confreres had raided his study twice, first to steal the wax tablets on which he was drafting the Proslogion, the second time to smash them. Rather than being the shared experiential context in which the arguments of the Proslogion seems intuitive, as Bayer holds, Niskanen suggests that a faction of Anselm's monastic community was opposed to it altogether as non-monastic and possibly heretical.

According to another work by Newman, his Benedictine essays, monastic intellectual life in the early Middle Ages had no place for speculative theology, among other reasons because getting absorbed in one's studies was likely to lead one to continue thinking about them when it was time to turn one's mind to prayer. Consistent with Newman's characterisation, Anselm reports in the proemium of the Proslogion that he was starting to think his obsession with finding his unum argumentum was bad for his prayer life, a manifestation of the intellectual vice of curiositas. I think the historical evidence suggests that Anselm was doing something novel in the tradition of monastic theology, knowingly and intentionally; Bayer's attempts to show his continuity with his predecessors ought to take better account of his novelty.

Bayer's book is most valuable for its discussion of Anselm's spiritual theology. It is less valuable for its discussion of Anselm's account of reason's role in the spiritual life. Bayer's attempts do help to keep that question before us, one which is so important both in general and in the study of St Anselm.