The thesis of this unusual and impressive volume is revealed bluntly by its title. The book's principal content derives from a seminar jointly conducted by B. and F. at Oxford in 2001. The seminar ran to eight sessions: five led by F., three led by B. The original plan called for F. to prosecute a case against the authenticity of the Seventh Letter and for B. to defend it; however, in re-reading the letter in preparation for the seminar, B. concluded that the defence had no case, and so he assumed second chair for the prosecution. D. Scott has the role of court reporter, although he goes somewhat beyond the usual office of editor by not only very ably reconstructing F.’s case (from what were quite full notes), but also adding substantial endnotes (with C. Atack) and a helpful guide summarising F.’s sometimes quite complex argument.

The two main parts of the book are quite different. F.’s presentations as recorded here are a striking reminder of what the world of classical scholarship lost with his death in 2007: they are a tour de force of erudition. On the basis of a quite thorough study of ancient epistolary literature, F. argues that the bar of presumptive authenticity is simply too high for any of the thirteen letters that have come down as part of the Platonic corpus to clear. The most important consideration here is that we have no certainly genuine letters by any philosopher before Epicurus; all of the other letters that present themselves as letters from philosophers are spurious. Since there simply was no trustworthy practice of collecting, preserving and transmitting letters before Epicurus, and earlier letters can be shown with various evidence to be pseudonymous, the existence of genuine Platonic letters 60 or 70 years prior to any of the genuine articles is too much to believe. Moreover, the first reference we have to a letter in the Platonic collection dates to the end of the second century (at the earliest), an awfully long time after putative composition. F. goes through some candidate letters from philosophers before Epicurus in great detail (e.g. Speusippus and Archytus of Tarentum), and his arguments about these seem quite convincing. F. also (and less convincingly) tackles the issue from the perspective of the content of the Seventh Letter. Here, he holds that the letter envisions Dionysius II operating as the kind of philosopher-ruler described in the Republic (pp. 43, 45–8, 52, 57, 59, 68–9, 71, 73, 75), but that this would be implausible given that Plato was, simultaneously with the letter, writing the Laws, which shows his hope for philosopher rulers to have been abandoned and replaced by an emphasis on the rule of law (pp. 49, 51–2, 56). In fact, the letter seems to advocate both philosophical rule and the rule of law, a point against it, since such a view could only be held by one who failed to understand the development of Plato's own political philosophy from the Republic to the Laws (p. 56). In addition to this, F. thinks it impossible for Plato to have taken Dionysius seriously as a philosopher (indeed, he thinks the same of Dion), which he would have to have done for the plan to work.

B.’s part of the book is in two pieces. He first presents a critical discussion of the famous ‘philosophical digression’ in the letter (342d–4d), which he argues was derived (most importantly) from the Cratylus by someone who was ‘philosophically incompetent’ (p. 122), thus aiming to block the fallback position taken by many that, even if the letter is not by Plato, it is by a philosopher close to Plato and therefore a valuable source. Second, he presents a lengthy and quite detailed interpretative essay on the whole letter, which interprets it as a ‘prose tragedy’, a literary form suggested by Plato in the Laws (817b, p. 136). It is a tragedy first for Dion, but more importantly for Plato, and most importantly for philosophy: ‘[the] tragedy of philosophy's attempt to change the world, not merely understand it’ (p. 138, cf. p. 189). He ingeniously divides the text into a prologue, three acts and an epilogue, and, while he intends that his interpretation supports his overall judgement that the letter is spurious, someone who supports authenticity could still read the essay with great profit, since it is full of interesting information and lavishly documented in the footnotes. One central theme running through the account is the letter's allusions to religion, in particular to the role of daemonic powers in the failure of the Syracusan project, an element that B. finds thoroughly un-Platonic (pp. 136–7, 143, 154–5, 181, 189).

Taken as a whole, this book is the most substantial treatment of the Seventh Letter we have and the most detailed brief against it since L. Edelstein's 1966 monograph (R. Knab's 2006 Platons siebter Brief, which reprints Burnet's text with a translation and commentary supports authenticity from the perspective of the Tübingen School). How persuasive is the prosecution's case? The first part of F.’s half of the book is exceedingly effective as far as it goes, but how far that is may be conditioned by the fact that the argument is circumstantial and probabilistic: in the end, it simply does not follow that because – putting Plato's letters aside – we do not have any authentic philosophical letters before Epicurus, Plato's letters cannot be authentic. It is a strong circumstantial case (and many people are convicted of crimes on the strength of circumstantial evidence), but it is unlikely to extinguish all doubt. The second part of F.’s account rests on an interpretation of Plato's political philosophy that can be and has been contested. It may be that most scholars still accept some kind of developmentalist account of Plato, but that account is considerably less dominant than it once was, in part because of the increasing attention paid by scholars to the dialogue form itself in its relationship to philosophical content. Moreover, F. takes Socrates' political proposals in the Republic to be both serious and accepted as such by Plato, where many interpreters see them as ironic. Even if one thinks Plato did propose government by communist polygamous philosophers in the Republic and abandon it for the rule of law in the Laws, there is still a problem, as Scott points out (pp. 95–6): one can interpret the Seventh Letter itself as telling how and why Plato changed his political views between his second and third visits to Syracuse, thus eliminating the seeming contradiction discussed by F. The interpretation of the ‘philosophical digression’ by B. is also contestable on some grounds (laying aside the possibility, suggested by some, that the digression may be an interpolation). The much longer and detailed interpretation of the letter is quite brilliant, so much so that, even with all the particular questions he raises about the text, B. leads one to think that it was produced by a highly talented and insightful writer – like Plato. While B. also provides a brief appendix (pp. 193–5) listing some instances of un-Platonic style, stylometry itself does not play much of a role in his account (or F.’s), and there is no discussion of G.R. Ledger's stylometric evidence that the Seventh Letter was written by the author of the Laws. Still, this volume constitutes a powerful counter to any easy acceptance of the letter and no student of Plato – and especially of Plato's political philosophy – can ignore it.