If the guide and commentary to the Summa Theologiae was a valuable tool, the same publishing operation concerning the Summa contra Gentiles can doubtlessly be considered a real novelty among the introductions to Aquinas's works. This book helps its readers, especially those who are not proficient in Latin, to appreciate the argumentative strategy of the Dominican Doctor as regards the issues belonging to the field of today's contemporary philosophy of religion. Proceeding from the latest results of historical criticism and in the light of his high philosophical competence, the English Dominican guides the readers to understand the meaning of the different chapters composing the Summa contra Gentiles. Moreover, expressing himself with the typical clarity of the British scholars, Davies comments on every thematic unity and explains the main philosophical issues. On the one hand, he responds to the most significant objections emerging from subsequent reflection and, on the other hand, he makes use of the contributions of many contemporary thinkers who somehow share Aquinas's position on this or that issue.
As regards the first group, we can mention the objections stemming from the thought of modern philosophers, like René Descartes (on anthropology) and David Hume (on the concepts of cause and miracle), the difficulties raised by modern biblical criticism against the achievements of natural theology, and the arguments elaborated, for example, by John Hick, Alvin Plantinga and Christopher John Fardo Williams. The second group of thinkers is quoted by Davies in order to illustrate and deepen Aquinas's argumentations, through the consideration of similar positions, in order to show how many sections of Summa contra Gentiles can be used within contemporary debate. Among the thinkers of this group, we can indicate William Alston, James Barr, Gilbert Keith Chesterton, Peter Geach, Anthony Kenny, Herbert McCabe O.P., Dewi Zephaniah Phillips, and Richard Swinburne. It is easy to understand, from the authors quoted, that Davies's reading of Aquinas aims at demonstrating the modernity of his thought in comparison with the debate in analytical philosophy.
In this context, we appreciate the general recourse to the linguistic method elaborated on the basis of Ludwig Wittgenstein's intuitions which give new life to Aquinas's writings. In particular, we can take as an example the way in which Davies introduces the readers to the philosophical notion of ‘cause’. How does he explain the meaning of this very important word in the horizon of Aquinas's work? Starting from ordinary language, Davies claims: ‘we might start by noting our familiar word ‘because’. We say that this or that happened or is happening because of something or other, and in doing so we seem to be seeking to offer explanations of some kind. The word ‘cause’ can be related to the word ‘explanation’. But there are explanations of different kinds just as there are reasons of different kinds’ (p.17). After different clarifications, a little further on – quoting from Philosophical Occasions (1921‐1951) – Davies adds: ‘Ludwig Wittgenstein (1889‐1951) once observed: ‘Calling something ‘the cause’ is like pointing and saying: He's to blame!’. We have a sense of ‘cause’ in which a cause is something that acts or operates so as to bring about what we take to be an effect. […] And this sense of ‘cause’ is what Aquinas has in mind when he speaks of agent or efficient causes’ (p.18). Proceeding from the known to the unknown, Davies introduces the reader to Aquinas’ philosophical lexicon starting from a shared linguistic competence. Explaining Aquinas and reasoning as an analytical philosopher are actions that can be realized simultaneously, showing in a different fashion the topicality of Aquinas's thought. If the analytical style characterises Davies's commentary to the Summa contra Gentiles, his examples have a predominant protagonist, i.e. the ‘cat’, traditionally the philosophers’ animal, which recurs in most of the examples proposed by the English Dominican. To mention one of these, consider this witty reflexion about the sublime issue of God's existence: Aquinas “does have a problem with the suggestion that we can know that it is God that we have encountered or perceived or stumbled across in something like the way in which we might perceive a cat and know it to be a cat and not, say, a dog. If I know, even without inference, that there is a cat in front of me, then, thinks Aquinas, I must have already acquired some concept of what a cat is. Yet, Aquinas asks, to what prior understanding of God can we appeal when claiming, on the basis of “perception” or “experience”, that God exists?’ (pp.34‐35).
Considering Davies's work from a more comprehensive viewpoint, it is clear that its core issue consists in re‐proposing Aquinas's thought on the relationship between faith and reason. This way of thinking is founded on the common origin of the two lumina (naturale and gratiae) from God and on the consequent impossible contradiction between them. This harmony mirrors the structure of the Summa contra Gentiles: without prejudicing revelation, Aquinas builds a natural theology (books I‐III) which flows into the revealed mysteries of the Holy Trinity and of the Incarnation (book IV). According to Davies, both in expounding his natural theology and in defending the articles of faith, Aquinas is convinced that ‘what reason can demonstrate cannot conflict with truths that God has revealed and cannot be proved to do so’ (p.14). Against a strong Barthian position, Davies endorses Aquinas's natural theology and, at the same time, shows how his theological reflection is biblically appropriate (cf p.305 and p.327). The commentator's position is clear: while Aquinas agrees with Barth on the importance of revelation, he ‘thinks, as Barth did not, that philosophy can be quite a useful aid to theologians’ (p.8). In short: even after the influential Swiss theologian's criticism of natural theology, we can read the Summa contra Gentiles fruitfully.
