Introductions to the Summa Theologiae are most successful when they recognise that St. Thomas's desire to offer a brief and clear introduction for beginners in sacra doctrina is qualified ‘… in as far as the matter allows’ (ST Prooemium). Thus multiplication of unnecessary material and repetition is to be avoided and likewise the order of instruction is to be followed; nevertheless, one who approaches the Summa will not find thoroughness and completeness sacrificed for pedagogical utility. A good introduction to the Summa then will, whilst not necessarily covering all the things one needs to acquire to understand the Summa, at least cover some of them, without at the same time inhibiting the acquisition of the rest of the material one needs to master. Of the two books to be considered here, McInerny's succeeds in this task whilst Torrell's does not.

McInerny's book is a translation of an essay by John of St. Thomas written to explain the order and connections of all the material in the Summa Theologiae. Collected together with two other essays, it formed an extended introduction to the same author's Cursus Theologicus. Here McInerny presents it on its own, again to help explain the order of material in the Summa, though one also suspects that if in addition to its usefulness for understanding the Summa, a reader also felt moved to consider John of St. Thomas's further work, the translator would not be distressed.

The book is divided into two parts; the first considers why there are three parts to the Summa and how the individual treatises in each part are related. The second part looks at the three parts of the Summa in more detail. All the major topics of the Summa are considered and reading it one acquires a good overview of the work as a whole. Most likely to prove surprising to today's reader is John of St. Thomas's division of the Summa into God considered in himself (Ia Q2- 43) and God's causal activity distinguished as efficient (Ia Q44-119), final (IaIIae and IIaIIae) and redemptive (IIIa). However, since this model is compatible with Chenu's exitus-reditus schema, it is unlikely to prove objectionable. Insofar as the book only intends to set forth the order and connections of the material in the Summa, it succeeds in its objective and does so without prejudice to any further material the student will need to master. Indeed McInerny's comment that the Summa‘… was written for theological, though not philosophical, beginners’ (p. x) is a recognition both that material other than this book will need to be acquired and a suggestion of what else will have to be included in that material. On these grounds then the book fulfils the requirements of an introduction and is to be recommended.

Torrell's book is the more ambitious of the two. Not limiting itself to a discussion of the Summa's structure and order, it also attempts to situate it in ‘… its historical, literary, and doctrinal settings’ (p. ix). Beginning with a brief account of St. Thomas's life, it then offers two chapters on the structure of the Summa. A fourth chapter discusses various types of medieval literature, relates the Summa to them and considers some of Thomas's sources. The last two chapters discuss the history of the Summa from the death of St Thomas to the present day.

Whilst there is much to admire in Torrell's book – indeed all the chapters contain useful information – nevertheless on certain points of detail his explanations are inadequate. For example how does Thomas's ‘strong personality’ (p. x) bring unity to his sources, and what type of claim is being made here? What criteria are being used to determine the importance of the sources? Hence, why is it that Thomas only ‘discretely disagrees’ (p. 74) with Augustine on occasion but does not ‘… hesitate to depart from Aristotle when he deemed it necessary’ (p. 76)? It might be that Thomas is more the Augustinian than the Aristotelian but that claim needs substantiation. Specifically, it needs to consider work done in the English speaking tradition (O'Callaghan, Klima and Haldane for example) on the decidedly non-Augustinian character of Thomas's epistemology and its role in Thomas's semantic theory.

However, Torrell's fundamental error stems from his assessment of the role of philosophy in the Summa. I want to make four comments: Firstly, why is it that knowledge of the living God of the Bible ‘… is not attained until he has been understood as a trinity of persons’ (p. 21) ? The thing to which ‘the living God of the Bible’ refers is the same thing as is investigated by reason alone and since sacra doctrina includes within itself those truths about God accessible to reason alone and is used by Thomas interchangeably with sacra scriptura (ST Ia Q1 art 8), there is no need to limit knowledge about the living God of the Bible to understanding him as a trinity of persons. Secondly Torrell's deist/living God of the Bible contrast is ill-judged. It seems to identify a philosophical account of God with ‘deist philosophers’ (p. 21). However, no scholar investigating those things that can be known about God by the use of reason alone thereby takes a deist position in an objectionable sense. Rather the objectionable character of deism depends on its limitation of God's involvement in the world, a position no Thomist qua Thomist, whether of a philosophical persuasion or not, can adopt.

Thirdly since sacra doctrina is true, arguments offered against it cannot be demonstrative (ST Ia Q1 art 8), and its claims then cannot be incoherent or else in principle contrary demonstrations would be possible. One way of showing that a claim is not incoherent is to try to demonstrate its truth, as Thomas does for example in the Five Ways and which, if successful, negates the charge of incoherence. Another way is to offer support for one's view by refuting the arguments offered against it. However, in both cases philosophical reflection is required and in neither case is the character of sacra doctrina negated. As Thomas describes sacra doctrina (ST Ia Q1 art 8), it is philosophically robust enough to withstand that form of assessment.

Fourthly Torrell frequently criticises what he terms a ‘deductive method’ for theology (p 51–2, 102, 113), preferring instead an ostensive one. The derivation of the general resurrection from Christ's resurrection in ST Ia Q1 art 8 is cited as an example of this ostensive method (p. 52) and a correlation is made between ostensive theology and the Latin term ‘ostendere’ (p. 51). It is not obvious what Torrell has in mind here but if the intention is to use a derivative of ostendere to draw a distinction between deductive and ostensive methods, the passage quoted does not support it. There Thomas compares other sciences and sacra doctrina. No science proves its own principles, rather it argues from these principles to other matters in the same science and sacra doctrina is said to be no different. However, given that Thomas uses ‘ostendendum’ to describe the derivation of conclusions both in the other sciences and in the science of sacra doctrina, then since the other sciences will include demonstrations within their derivation of conclusions, the ostendere derivative must include demonstrations within its intension. Moreover, since demonstrations are types of deductions, then deductions are included within the ostendere derivative a fortiori. That being the case the passage cannot distinguish a deductive method from an ostensive one but only as one type of ostensive method.

To get the best from Torrell's book one needs to ignore what he says about philosophy in the Summa and matters related to that. To the extent that the book is wrong on the role of philosophy in the Summa, it inhibits the reader from mastering the material they need to acquire and as such fails as an introduction.