Brian Davies is a distinguished scholar of philosophy of religion, with a special emphasis on Aquinas. Over four decades he has built up an impressive body of material characterized by lucidity, even-handedness, and a penchant for feline examples. One of his early books, The Thought of Thomas Aquinas (1992), is still an excellent resource for anyone seeking to get an overview of all of Aquinas's work, both philosophical and theological. This new book covers much of the same territory, but with its focus firmly on the text of the Summa Theologiae. And many of the same controverted issues, about the relationship of faith to reason, theology to philosophy, and grace to nature are revisited in this treatment.

There is a long tradition of commentarial material on the Summa Theologiae surviving right from the medieval period, including the Franciscan Correctorium Fratris Thomae (1278) which seeks to put it to right, the canonical commentary of Cajetan which is printed in the Leonine edition, and the well-known twentieth century work of Walter Farrell. Each of these is responsive to its historical context and highlights different features of Aquinas's work. Davies writes within an identifiable interpretative tradition and frequently refers to his teacher, Herbert McCabe. What characterizes this approach is an engagement with contemporary analytical philosophy, an awareness of current debates and issues in related fields (e.g. psychology, ethology, natural science), and a willingness to identify problems and errors in Aquinas's work when they emerge. However, there is also a palpable respect for Aquinas's achievement and a conviction that it isn't merely history of ideas, but can contribute to contemporary philosophical and theological debate.

Specifically Davies attends to two important interrelated aspects of Aquinas's work. First, there is attention to Aquinas's theorizing about language and how he uses some technical issues in philosophy of language (such as predication, i.e. how predicates are ascribed to subjects) to make significant substantive points about our knowledge of God, the coherence of the divine nature, the non-illogicality of the Trinity, and the Eucharist. This connects, second, to taking seriously the apophatic dimension of Aquinas's work. On this view, Aquinas doesn't argue for God's existence, but rather argues for the rationality of asserting the sentence ‘God exists’. Putting things in this formal linguistic register keeps clear the crucial claim for Thomas that we do not know what God's existence is like, which is part of the basis for his rejection of the ontological argument. There is also a tendency to deflate the sometimes baroque metaphysical claims associated with Thomists (and to distinguish Thomas from the Thomists). Hence fans of intricate discussions of the analogy of being or elaborate treatments of participation will be challenged by Davies's astringent reading, as will those who can find no wrong in Thomas.

The opening chapter which introduces Aquinas, the context and setting of the Summa, and its potential audience is concise, thorough, and contains many gems – such as noting that the studium set up for Aquinas in Santa Sabina in Rome ceased to exist when he left it in 1268, that he was paid an ounce of gold a month to teach theology at the University of Naples in 1272, and that he spent only seven years of his life working in a university. There is a judicious assessment of Boyle's argument about the intended audience for the book and also of Chenu's argument for its exitus–reditus structure.

Chapter 2 discusses Sacra Doctrina, the kind of theology which arises from Christian revelation and which is distinct from the kind of theology available in philosophy. Davies repeatedly notes a problem with Aquinas's approach to scripture. Aquinas believes that scripture is historically accurate and contains a reliable account of the life and teaching of Christ. Most modern biblical scholars express doubt about this. This issue recurs at several points. Davies notes Aquinas's belief in the historicity of Adam and Eve, although he also notes that Ia 94–102 can be read as articulating ‘the idea that there is a bodily state of perfection available to people were it not for the fact of them being separated from God by sin’ (149). However, Davies notes that much of the discussion of original sin (Ia–IIae 81–85) not only rests on claims about the historicity of Adam, which few contemporary exegetes would support, but also on erroneous views about what affects what in human procreation (396).

Chapters 3–6 cover Ia 2–43. There are clear concise discussions of the five ways with helpful footnotes to further scholarship. Davies responds to some of the more familiar standard objections (that the conclusions don't follow from the individual arguments, that they fall foul of Newtonian physics, that they exhibit logical fallacies). He emphasizes the prologue to Ia q.3, where he says:

The various Divine attributes are discussed, and with a quite detailed discussion of Ia 13 on theological language, which Davies describes as a kind of State of the Union address, dealing with where we have got to so far and where we should go from here. Analogy is briefly treated, but with a McCabe-style deflationism. Davies's commentary on Ia 27–43 emphasizes the relationship of the doctrine of the Trinity to divine simplicity and our lack of understanding of it – ‘We need to remember, though, that, for Aquinas, our reason has already seriously broken down as soon as we begin to talk positively about God at all’ (97). We need to rest content with the thought that we are not breaking any rules of logic in dealing with the Trinity and should not be fooled into thinking that we know more than we do. Nevertheless, ‘the doctrine of the Trinity is, for Aquinas, the life-blood of all good Christian teaching. It is not of merely esoteric interest to him and it is not a dispensable appendix to his treatise on God’ (108). Perhaps some further elaboration of how this is so and how it integrates with the apophatic theme would have been helpful.

Given the wealth of material in the Summa, Davies has to make decisions about focus and scope in his commentary. He describes the book, in a memorable image, as a kind of theme park in which people with an interest in God and Christianity might roam, whether they like or not what they find (125). However, he also notes its systematicity and the logical progression of topics.

For example, Davies devotes chapter 8 to ‘Angels and the Days of Creation’, Ia 50–74. He suspects they are among the least read parts of the Summa, explaining why interest in angels was higher in the thirteenth century than now, even in theology. Yet he shows how there are matters of metaphysical and epistemological interest in Aquinas's treatment, whether one believes that angels exist or not. Angels lack matter and so have to be individuated by form, each one being a distinct species. They are also pure intellect and there is an issue as to how they might know – cognition in humans starting in the senses. They lack emotions, which have an irreducible physical component, yet they are capable of sinning – their sin being that of pride (and Davies notes that sexual sins are right down the hierarchy of grave sins for Aquinas, since they affect the lower part of our nature (205)).

Aquinas has a lengthy treatment of emotions in Ia–IIae 22–48. Davies gives a general overview of this followed by a more detailed discussion of specific points, a structure he repeatedly and effectively uses. Davies says: ‘the 1a2ae treatment of emotions is one of the most sustained and sophisticated philosophical treatments of emotions coming from any period’ (170). Emotions arise in us because we are animals of a certain kind (e.g. ‘fear involves a strong physiological element’ (185)), yet they arise because of what we take to be the case intellectually, hence Aquinas is a cognitivist about emotion. Against a certain kind of Stoical approach, Aquinas argues that emotions are not bad: although they can overwhelm us and lead us to act badly, some emotions are positively needed to act well. Again, the notes provided by Davies are very helpful, alerting readers to recent work on specific topics – in the case of emotion, work by Peter King, Nicholas Lombardo, and Robert Milner.

The vast sweep of the IIa–IIae is covered in five chapters. Davies assesses as he goes. He notes that Aquinas's ‘discussion of unbelief in Ia–IIae is clearly affected by ignorance and might be compared with things that he has to say related to certain antiquated scientific views to which he was heir’ (236) – the ignorance being of non-theistic religions and of the global and historical development of religion. He described Aquinas's account of prudence as ‘fairly complicated’ but also notes that it is an account of practical reasoning in contextual use and so cannot be highly prescriptive (250). Interestingly, Davies notes that ‘Aquinas regarded prayer as an exercise in practical reasoning’ (261) and goes on to look at objections to prayer (it is unnecessary since God is omniscient; it is an attempt to change an immutable God; it is redundant since God is generous) and answers showing how Aquinas does not think of prayer as informing or seeking to change God (262). Davies also notes that Aquinas discusses virtues and vices which don't appear in contemporary treatments, and indeed transforms some of Aristotle's versions of them. Davies is critical of Aquinas on the ranking of sexual sins which, he believes, rests on faulty physiology and drily notes: ‘you will not, I think, find many contemporary moral theologians arguing, for example, that masturbation is more evil than rape’ (280).

In discussing the ordering of topics in IIIa 1–26, Davies says: ‘a discourse on the Incarnation follows most naturally upon a discussion of those for whose benefit it was intended’ (291). Returning to the basic theme of apophaticism Davies echoes McCabe: ‘For Aquinas, when it comes to Christ “we have two ways of speaking of him – only one of which we understand”. . .’ (296). He focuses on IIIa 16, which he says reads like a quiz on the previous questions – again focusing on issues of predication. Can we predicate of the divine nature what is attributed to the human nature? (definitely not!); Can we predicate of God what we attribute to human nature? (yes!); and so on.

The discussion of the Eucharist and transubstantiation is especially useful for illuminating Aquinas's use of Aristotle. The apophatic theme is repeated by Davies; Aquinas isn't demystifying the Eucharist by the use of Aristotelian terminology. He frequently departs from ways in which Aristotle wrote about substance, accident, and change – Davies approvingly cites McCabe again on the Eucharist, ‘It is not a notion that can be accommodated within the concepts of Aristotelian philosophy; it represents the breakdown of the concepts in the face of a mystery’ (343).

Davies presents an assessment of the Summa Theologiae in chapter 23, where he summarizes many of the problematical issues he has discussed throughout his book. Concluding, he says:

Davies has interpreted Aquinas's great work in a way that makes it intelligible, interesting, and thought-provoking to a wide audience. His discussions challenge liberal and conservative Christians, atheists and agnostics alike. It is an excellent addition to Aquinas scholarship.