To properly understand Seneca’s philosophical writing, one needs to appreciate his sharp and often satirical wit. Any sensitive reader can observe that the Letters on Ethics, in particular, employs many standard humorous devices to lighten the tone and to hold the reader’s attention. Examples can be given of punning, incongruity, self-caricature, and more elaborate vignettes that recall the verse satires of Horace. But there are also instances in which Seneca’s humor is directed specifically at certain modes of philosophical speech and writing: the redeployment of Epicurean sententiae in letters 1–29; the cavillatio or trick syllogism of letters 45, 48, and 49; and the riff on Stoic metaphysics in letter 113. In these cases, one can best refer to the well-attested function of Roman invective humor as a means of policing boundaries. By them, Seneca communicates certain rules of generic decorum while also alerting readers to his own deliberate transgressions.

Chapter 9 assesses Seneca’s claim in the Letters on Ethics to provide moral benefits to his future readers. Although he may not have read Plato’s Phaedrus, Seneca is certainly aware of the arguments Socrates makes there concerning the efficacy of writing. In his own work, Seneca sometimes seems to echo Plato’s points that writing cannot improve the character of the reader because it lacks the immediacy, the adaptability, and the interactive possibilities of spoken discourse. At the same time, however, he comments both explicitly and implicitly on the means by which a written work can indeed take on some of those characteristics when it is presented in the novel format adopted for the Letters on Ethics. Invoking the commonplace that letters have the potential to make the absent present, he develops a variety of strategies for creating a lively sense of authorial presence, for training the reader in methods of application, and for engaging the reader in a quasi-dialogic interaction with the text. Further, he explores the emotional dimension of the reader’s experience in ways that are surprising for an author of his Stoic commitments.

The first chapter considers Seneca’s views on the life of studious leisure (otium) in relation to the therapeutic purpose that he claims for all his philosophical writings. In his essay On Leisure, Seneca explores several standard defenses of the contemplative life (Aristotle’s βίος θεωρητικός), indicating clearly that such theoretical pursuits as astronomy and metaphysics are worthwhile pursuits in their own right. Yet there are tensions in his position, for he also suggests that the expenditure of time that philosophy requires is justified primarily by the moral benefits it conveys to oneself and, through the medium of writing, to future generations. In the Letters on Ethics, the latter claim is put forward as the very reason for the book’s existence, a generic imperative to which the entire content should refer. Consequently, those purely theoretical investigations that (nonetheless) appear in the Letters are present on sufferance and must be excused by a series of deliberately transparent rhetorical devices.

What should we make of the glaring absence of the emperor Nero from Seneca’s Epistulae morales – not mentioned once in 124, often lengthy, letters, written by a man who had been for many years one of his closest associates? Although Seneca does sometimes allude to the question of how frank advice may be offered to the powerful, the letters barely touch on imperial politics, beyond advising their addressee that he would be better off withdrawing from the public sphere. Yet if Nero is not present explicitly, there are a number of respects in which Nero’s domination of others as well as his failure to exercise control over himself are constructed as implicit and potent anti-models in the letters. When Seneca reflects on the dynamics of vice in its more florid and imaginative forms (the examples analyzed here are letters 90 and 114), his terms frequently resonate quite specifically with ancient accounts of Neronian Rome (notably those of Tacitus and Suetonius) and other works of Neronian literature (particularly Petronius and Persius). As it turns out, highly refined vices even play a notable role in Seneca’s model of the development of philosophy.