The dialogical form of almost all of Plato's works has attracted radically different interpretations (including, at one extreme, D. Boyarin's reading, Socrates and the Fat Rabbis [2009], of the Platonic dialogues as disguised monologues; and at the other extreme, the periodically revived sceptical reading, dating back to antiquity, on which the dialogues are inherently aporetic). L. intervenes in a carefully circumscribed spectrum of these debates. His targets are those (including R. Robinson, C. Rowe, F. Gonzalez and C. Gill) who ‘claim that in Plato's eyes philosophy requires conversation’ (p. 2). In this lucid monograph, L. rejects this as a claim to be ascribed to Plato based on the fact that he wrote dialogues. Instead, he reads a select group of Plato's works as engaging in critical, and evolving, explorations of just such a claim, treating the relationship between philosophy and conversation as a topic for Platonic inquiry arising from, and within, his method of writing. According to L., Plato's explorations differentiate that relationship along at least three dimensions: (i) among different forms of philosophising; (ii) between Socrates and other people in the nature of their philosophising; and (iii) between external conversational dialogue among people or characters, and internal dialogue within a single person or character in the process of thought (I will follow L., p. 4, in reserving ‘conversation’ for ‘interpersonal, spoken exchanges’).

L. interprets a subset of the dialogues as determinate records of this process of reflection. To do so, he adopts an explicit and now relatively unfashionable (though he calls it ‘mainstream’ in certain branches of Anglophone scholarship, p. 8) ‘developmentalist’ perspective on the sequence of his chosen dialogues. While for much of the ordering he relies on ancient evidence or on stylometry, one crucial part lacks any such evidence, as L. acknowledges (p. 9): this is the dating of the Protagoras before the Symposium, a philosophical interpretation made by L. but doubted in a recent introduction to a translation of the former (M. Schofield and T. Griffith [trans.], Plato: Gorgias, Menexenus, Protagoras [2010], pp. xxiv–xxv, noted in L., p. 65 n. 3). In my view, L. might do well to present his overall project – selectively interpreting a sequence of dialogues as engaging in an ongoing programme of philosophical exploration – as a new breed of ‘developmentalism’ altogether. Philosophical interpretation is arguably a better overall foundation for ordering the dialogues than stylometry (which in any case needs updating by new computer techniques).

While adopting a traditional developmentalism overall, L. also employs the more fashionable literary approach to the dialogues to good, if subordinate, effect. He reads the dramatic action of the dialogues as commenting upon the arguments that they contain, and so as crucially modifying the philosophical perspectives that can be attributed to Plato. He is careful to distinguish between the positions advanced by Socrates; those reported by Socrates in narration but not available to other characters in the dialogues; and the views that Plato himself may have formed or held, leading him to construct the dialogues in certain ways.

Eight dialogues are named in the table of contents; in addition, Chapters 2–4 contain significant interspersed discussions of relevant aspects of the Gorgias and Symposium. Following an introduction, Chapter 1 rebuts the claims of A. Nightingale and C. Griswold that the Phaedrus shows that philosophy inherently requires or consists in conversation with others. Instead, L. defends R. Robinson's older thesis that the dialogue's praise of conversation is directed towards philosophical teaching rather than discovery, while also adding conversion to philosophy to the list of what conversation can do. Chapter 2 focuses on the need that Socrates declares for conversation to ‘confirm’ (βεβαιώσηται, Protagoras 348d5) the results of philosophical inquiry, a confirmation that comes best from someone like Protagoras who is an ‘opponent’ of his philosophical views (p. 43). But since the Protagoras also shows that people's views (such as the views of the Many) may be examined in their absence (and indeed Callicles' withdrawal in the Gorgias forces Socrates to take on the part of respondent as well as questioner at one stage, before giving up the question-and-answer conversational format altogether: pp. 48–51), this opens the door to the Hippias Major (Chapter 3). Here, with Hippias presented as an unsatisfactory interlocutor, Plato instead makes Socrates examine his own views in internal rather than external dialogue (playfully calling himself his own ‘housemate’). The same prospect of pursuing philosophical inquiry through internal dialogue is dramatised in the Phaedo (Chapter 4), but given poignancy by the value that Socrates himself places on ‘conversations past and present’ and that his friends even more strongly attach to their conversations with him (p. 86). Here is a nice illustration of L.'s method of appealing to the dramatic action of the dialogue in interpreting its philosophical claims: ‘Socrates’ suggestion [to his soon-to-be-bereaved circle of friends] to replace him [as a philosophical mentor] is preserved in an account that presents him as irreplaceable' (p. 75).

In Chapter 5, L. returns to a schema rooted in the Gorgias. Whereas there Socrates' turn to ‘self-questioning’ had been an ‘unwelcome necessity, forced on him by a stubborn interlocutor’ (p. 50), ‘[i]n the Hippias Major and Phaedo … Plato suggests that questioning oneself is not merely a desperate expedient’ (p. 87). The Phaedo canvassed two solutions to the Gorgias problem – ‘conversation with allies and dialogue with oneself’. Of these, the latter is explored in the Hippias Major, while the former (L. argues) dominates the Republic, a dialogue in which Plato demonstrates ‘that Socrates’ opponents can be represented by those who are on Socrates' side' (p. 87), and that conversation with those allies can serve to persuade them themselves, especially when, as with Glaucon and Adeimantus, they are allowed sometimes to take control of the conversation.

While the Republic portrays the value of external conversation (even though itself persuading through writing rather than conversation, p. 106), the Theaetetus and Sophist complete L.'s survey of Plato's evolving views on the value of internal dialogue (Chapter 6). Whereas in the dialogues considered up until this point in the book, internal dialogue has been explored ‘primarily as a part of Socrates’ intellectual life' (p. 109, emphasis added), ‘[i]n the Theaetetus and Sophist Plato makes a bolder and more general claim [applying to everyone]: to think is to question oneself’ (p. 109). L. concludes that these dialogues show that ‘a philosopher can without external aid stage a fair debate with his opponents’. This is motivated by the consideration of opponents such as the Heracliteans (Theaetetus) and the unreformed corporealist giants (Sophist) with whom dialogue would be literally impossible, even though these opponents may not themselves be ‘persuadable’ (p. 138).

Thus concludes the argumentative arc begun in Chapter 2. Chapter 7 steps outside this trajectory, arguing that the foreign conversational partners of the Athenian visitor in the Laws are not essential to that dialogue's ‘new cosmopolitanism’ (p. 139), a perspective which derives rather from the Athenian's own experience of the customs of other cities as exactly the kind of θεωρός that he recommends the Nocturnal Council should institute in Magnesia (Lg. 951c6; see L.'s helpful comparison with Socrates' remarks at Crito 52b1–c1, 52e, Ap. 30, and his use of Nightingale 2004, p. 153 with n. 34). The book ends rather abruptly with this chapter rather than with any concluding remarks.

L.'s book does a signal service by challenging too facile assumptions that find an unchanging, non-coercive and constructive, and necessary role for interpersonal conversation in any and every form of pursuing philosophy. The book is equally valuable in considering in a single conspectus, the often separately analysed topics (in Platonic studies) of dialogue form, the value of conversation and the consideration of thought as a process of internal dialogue. By showing how the possibility, and value, of interpersonal conversation and intrapersonal dialogue are explored by Plato in a variety of ways and contexts, L. has made a clear, valuable and original contribution to the field of ancient philosophy.