Rhetoric, says Aristotle, like dialectic, is practised by all persons, in so far as everyone, to an extent, attempts to defend his own views and to criticise those of others (Rh. 1.1, 1354a). Such conversation is a fundamental part of human social life. Each of us – with varying degrees of self-awareness, expertise and deliberate method – is a rhetor of a sort. We all participate in what can be called – to use a broader term – the practice of argument. We tend to think, moreover, if we reflect upon this practice, that the object of our argument is to influence the ideas or thoughts or feelings of others. How many of us would speak of using argument to affect others’ souls or of the art of argument as a kind of caring for souls? Yet precisely such an understanding of argument – in particular of its social or political dimension and of its effect upon the soul – is essential to Plato's thinking on rhetoric, politics and philosophy as found in his Gorgias and Phaedrus. So at least argues I. in his provocative new book.

The central claim of I.’s study is that for Plato our approach to argument ‘typically reveals something at a deeper level about our desires and motivations, particularly with respect to others, and so the key to engaging in argument correctly … is found in [Plato's] understanding of the human soul’ (p. 3). I. develops this claim through a systematic interpretation of both the Gorgias and the Phaedrus, arguing that the latter's account of human psychology justifies and explains Socrates’ assertion in the Gorgias that his own way of seeking wisdom is a kind of caring for the soul, which he identifies with the art of politics.

Part 1, devoted to the Gorgias, argues that the difference between ‘conventional rhetoric’ – I.’s term for the rhetoric practised by Gorgias, Polus and Callicles – and the philosophical practice of Socrates turns upon the speakers’ differing attitudes towards the practice of argument, attitudes that themselves reveal a difference in attitude towards others. For Gorgias, Polus and Callicles, rhetoric is a kind of ‘competitive skill’ (ἀγωνία, Gorg. 456c8): prowess in speech produces personal prestige which secures political power. Power over others is the conventional rhetor's real goal, persuasive speech merely the means of securing it. But since prestige and the power it brings are zero-sum goods, such a rhetor necessarily regards other speakers as rivals. In every verbal contest, there is always a loser. And when argument is so conceived, every defeat entails a loss of prestige and thus a loss of power.

Socrates, on the other hand, has a fundamentally different attitude towards argument. Whereas for the rhetors of the Gorgias skill in argument is a competitive skill aimed at vanquishing an opponent, for Socrates argument is a fundamentally cooperative endeavour in pursuit of a good that is beneficial to all – namely, wisdom. Socrates in fact describes his own engagement in λόγος as a kind of care (θεραπεία) for the soul, which is the basis of his claim to be engaged in – or at least to be attempting – the political art (521d). But to establish that Socratic conversation, as depicted in the Gorgias, really is beneficial to Socrates and his interlocutors, Plato needs to give a compelling account of the nature of the soul, its characteristic good and distinctive desires – which is precisely what we find in the Phaedrus.

Here, in Part 2 of his study, I. directly confronts the problem of the dialogue's unity arguing that ‘the first part of the dialogue relates to the second by providing the moral psychology necessary to engage in proper philosophical discourse’ (p. 113). Stated most provocatively, I.’s claim is that ‘essential to the art of argument, according to Plato, is the art of love’ (p. 7). In the first two speeches of the Phaedrus, Plato develops an account of erôs as a purely pleasure-seeking drive. This account of erôs corresponds to the view of the soul assumed by the practice of conventional rhetoric in the Gorgias. But in the palinode a different picture emerges – one of erôs as consisting ‘in the discovery and appreciation of features in a person that inspire a kind of striving’ –, which Socrates finally describes as the best kind of friendship (p. 115). This philosophical kind of erôs is based upon the lover's recognition of the rational nature of his beloved, and it unites lover and beloved in a common quest for wisdom – the beloved thus becoming a companion in learning rather than a mere provider of pleasure – or of power and prestige, if we are thinking of the rhetors in the Gorgias.

Socrates famously describes such philosophical erôs as a kind of ‘madness’ (μανία, 249d5) – a madness owing to our recollection of the forms our soul once beheld directly while travelling with a god. Taking the entire chariot allegory of the palinode ‘as a parable for the practice of philosophy’ (p. 139), I. argues that our recollection of the forms, which we experience in philosophical conversation, amounts to a kind of internal compulsion emerging from the rational part of our soul which is akin to the forms. The passage suggests ‘a portrait of exhilaration: a feeling of being led ineluctably by something beyond oneself that at the same time reflects the truest part of oneself’ (p. 141). Beholding things as they really are, the philosopher is ‘both disoriented and at one with himself, held captive yet set free’ (p. 142). Herein, moreover, lies the critical difference between the kind of responses philosophy and conventional rhetoric elicit from others. Where the conventional rhetorician aims only to win the argument and so will use any available means of refuting his opponent, the philosopher's power in argument consists in his ability to provoke independent thought. Socrates does indeed employ a kind of compulsion in argument, but it is a compulsion arising from the soul's own rational nature, from the soul's innate love of the forms, which is awakened through philosophical conversation. And ‘[w]hat results is a collaborative activity between partners rather than the unilateral force exerted by the rhetorician’ (p. 143).

Apart from the sustained argument I have outlined here, I.’s study is full of other useful insights: that Socrates’ critique of ‘flattery’ (κολακεία) is focused upon the fact that flattery promotes not the pleasant instead of the good, but rather what is pleasant as good (p. 51); that Callicles’ endorsement of hedonism can be explained by the unreflective nature of his position, which is tied to his conception of the superior man (pp. 89–90); that the palinode is indeed directed primarily (though not exclusively) at the rational part of Phaedrus’ soul (p. 151) – which, though not a line taken up by I., throws the concluding myth of the Gorgias into a new light. My only reservation has to do with I.’s apparent equation of the true rhetorical art and philosophy: ‘the practice of philosophy according to my reading just is the art of rhetoric for Plato: a kind of soul-leading governed by the pursuit of wisdom’ (pp. 5–6) – an equation that does not seem demanded by his arguments.

Beyond the substantial contribution it makes to the study of the Gorgias and the Phaedrus, I.’s book can serve just as well as a contemporary apologia of the love of wisdom based upon its social value. What a society needs for its flourishing is not more effective instruments of satisfying its desires, whatever they happen to be, but a method of assessing those very desires, of discovering what is really good and noble and just. When a society – like that of Socrates’ interlocutors, Callicles, for example – abandons, or simply loses interest in, the pursuit of wisdom, the inevitable consequence is a debasement of our interpersonal relations, especially as those relations are formed and sustained through rational discourse.