This work is a sequel to S.'s Levels of Argument: a Comparative Study of Plato's Republic and Aristotle's Nicomachean Ethics (2015). Though not equipped with a comparable subtitle, Listening to Reason (LR) is similarly structured in two halves, principally comparing the same two works of Plato and Aristotle respectively (both of the monographs also delve occasionally and in similar confines into the Politics, and LR devotes its conclusion to a brief comparison of both Rep. and NE on habituation and education with Plato's Laws), and with some well-chosen repeated or summarised material from the 2015 monograph where relevant to the 2020 one. Both lucidly written, they treat key texts and topics in the spirit of philosophical specialists. I begin by characterising the two linked projects. Levels of Argument (LA) asks ‘what sort of discipline do [Plato and Aristotle] consider ethics, or more generally, practical philosophy to be’ (LA p. 2), distinguishing three different ‘routes’ (shorter, longer and middle) in terms of the extent to which ethics depends on ‘abstract theorizing about metaphysics, epistemology, and psychology’; both the Republic and the NE (S. there contends) take the shorter route: ‘Plato because he thinks it will have to suffice, Aristotle because he thinks that there is no need to go beyond it’ (LA p. 5). So, whereas LA asks about the actual route taken in each work (Republic and NE), as well as the general evaluation of each of the three routes by each philosopher, LR, by contrast, seeks to ascertain the views that can be inferred from the two focal works (augmented on occasion by appeal to others) on a question that neither of them poses explicitly, namely: ‘[assuming that] the vast majority of people are familiar with moral argument, how many of them could be reasoned into valuing moral virtue in this way’, that is, into valuing moral virtue ‘for itself’ (LR p. 2)?

LR claims that both of the focal works converge in practising what S. in LR calls ‘reinforcement’ of their moral beliefs, as opposed to ‘conversion’ of someone who does not already share those beliefs: for example, ‘[Glaucon and Adeimantus] need reinforcement, not conversion’ (LR p. 46); Aristotle in the NE ‘cannot be addressing the moral sceptic’ (LR p. 130). This claim complements the general attack of LA on the more usual view ‘that Plato and Aristotle systematically base their ethics and politics on their own distinctive brands of metaphysics’ (LA p. 5), since the possession of the correct moral views with which S. credits Glaucon and Adeimantus does not require them to have already learned such metaphysics. S. does not claim that Plato only ever focuses on moral reinforcement, acknowledging that in the argument with Callicles in the Gorgias, Socrates makes ‘an attempt at conversion, not reinforcement’ (LR p. 135), but this begs the question of whether such efforts can ever succeed, not addressed in the present work.

I turn now to LR alone (to which all citations henceforth refer). Framed by a general introduction and conclusion, Part 1 (in an introduction, six chapters and interim conclusions) focuses on the Republic, while Part 2 (in an introduction and six chapters) focuses on the Nicomachean Ethics. In Part 1, the first three chapters treat the three levels of argument identified in LA, exploring the relationship to possessing or acquiring moral virtue in the audience which each presupposes; the next draws thematic material out of the Republic on the question of education as it shapes receptiveness to argument; and the final two discuss the extent to which the flawed character types who populate the individual track of Books 8 and 9 can be amenable to reason. S. draws the interim conclusion that, notwithstanding the problematic ‘intransigence’ to philosophy exhibited by the oligarch, democrat and tyrant, the dialogue still displays a ‘qualified optimism’ as to the possibility that philosophical argument might persuade the many, at least, ‘that justice is valuable for its own sake’ (p. 114), if not of the case for philosopher-rulers (leaning heavily on a passage in Book 6 [498c5–502a3]).

Before turning to the treatment of the NE, let me make some observations on the discussion of the Republic. A peculiar feature of S.'s guiding question, and his approach to answering it, is that he is forced to draw overly sharp lines between what does and does not count as ‘moral’. For example, he remarks that in the Republic, ‘to reinforce his interlocutors’ commitment to the just life, Socrates appeals to … non-moral values that they already espouse’, such as health, psychic harmony, friendship, security and trust: he calls this ‘external reinforcement’ as an argument ‘for the value of justice without appealing to any moral intuitions’ (p. 134). But are friendship, security and trust (which S. rightly notes are central to Book 9, 578a4–5 and 580a3–4) genuinely ‘non-moral values’? And as a separate issue, does S.'s aspiration to the strategy of external reinforcement founder on an is–ought problem? In a thematic observation in Part 2 S. indicates that the role of ‘external reinforcement’ is to ‘attack the sceptical position without addressing an actual sceptic’ and to do so by arguing ‘from neutral premisses’ (p. 147). But if the overall purpose of the Republic, in regard to Glaucon and Adeimantus, and by implication to its readers, and of the NE, is ‘moral reinforcement’ rather than ‘conversion’, why should the path of external reinforcement be prioritised? (The discussion of these questions is muddied by the use of the label ‘protreptic’ for ‘any argument that attempts either to convert someone to the moral life or to reinforce their commitment to it’ [p. 134], a disjunctive definition that is rather strange in light of the overall distinction between conversion and reinforcement on which the monograph hinges.)

In Part 2 S.'s approach devolves into distinguishing between different approaches to the guiding question taken in different parts of Aristotle, without offering an overall assessment of how the reader of Aristotle could best put all these pieces together. He offers a helpful overview of the NE as ‘an exercise in legislative science’ (p. 121), but one that is also useful for the individual. Yet the extent to which this project makes the audience and purpose of the work significantly different in kind from the Republic is not further explored. Then, having offered a helpful analysis of the relationship between the NE and the Politics, and set out his stall on the ‘fractured’ nature of the pieces of the Politics, S. goes on to argue that the Politics is overall more optimistic about the possibility of moral argument succeeding, but again without taking the measure of why this might be so. The chapters in this Part include some thematic ones on the relevance of the character of youth, those who live by akrasia or pathos, and the many, in different parts of the NE, in relation to its audience, as well as an extended critique in Chapter 11 of the readings of Aristotle on women offered respectively by W. Fortenbaugh and M. Leunissen, which itself would repay the price of admission. The conclusion to the monograph compares both the Republic and the NE briefly with Plato's Laws on the question of persuasion by argument, opening the door to what could be a rich field for further investigation. Overall, a thoughtful and in many cases original treatment of a succession of key passages in Plato and Aristotle, as well as the extension of S.'s trademark comparative approach to the Republic and NE, make this monograph a valuable contribution to the literature.