The tradition of critiquing Seneca's writing style dates to his own lifetime. Caligula declared it to be ‘sand without lime’ (Suet., Cal. 53.2). Soon after Seneca's death, Quintilian, Aulus Gellius and Marcus Cornelius Fronto offered detailed and mostly critical comments. Seneca's style continues to be an area for research and analysis, but primarily from a more positive and appreciative angle. Tommaso Gazzarri's book follows this trend and builds on previous studies of Seneca's metaphors by Mireille Armisen-Marchetti and others. He also looks at modern theories of metaphor, in particular those of George Lakoff and Mark Johnson. G. stresses that for Seneca metaphors are not mere ornament, but rather a key means to fashion and improve the soul. The affective nature of Seneca's metaphors is interpreted via both cognitive theories of metaphor and Stoic materialism. Thus, G. argues that Seneca's metaphors affect the soul of the reader due to Stoic views on the bodily nature of the self, cosmos and text. Linking Seneca's figurative style with the tradition of his death recounted by Tacitus, G. argues that Seneca's prose writing serves as a medical instrument. The stylus is a scalpel.

The book is divided into two parts. After an introduction, there are three chapters on the theory of Seneca's metaphors and three on the practice. In the first half, G. sets Seneca's use of metaphors within the Aristotelian tradition (18–25). G. argues that, in contrast to Cicero and Quintilian, who he believes saw metaphors primarily as ornament (27), Aristotle attached cognitive value to the figure. G. then explores Stoic cognitive theory and focuses on Seneca's presentation of the ‘pre-emotions’ at the opening of the second book of De ira. As Seneca notes there, these ‘preliminary preludes to emotion’ can be elicited from literature and theatrical spectacle (2.2.1–6). G. posits that these pre-emotions provide a safe opportunity for painless contemplation and moral improvement (90–5).

In the second half, G. explores the ‘medicalization of Seneca's style’. He discusses Seneca's connections to Greek and Roman medical writers, as well as to the general Roman idea of the medicus amicus. Thus, Seneca is placed in the familiar tradition of the philosopher as physician to the soul. G. explores the some of the techniques that Seneca employs to effect a cure. One is ‘accumulation’ or ‘metaphorical clusters’ (123–30). According to G. these clusters present key ideas from multiple angles in order to offer the opportunity for the soul to be trained repeatedly in a short space. Ep. 104.17–18 and QNat. 1 praef. 4–5 are given as examples of this technique. As G. notes, Seneca does not provide his own theory of metaphor. Yet he is not silent on the topic. At Ep. 108.35, Seneca writes that Lucilius should avoid using excessive metaphors and figures of speech (translationes inprobas figurasque dicendi). How this recommendation might line up with Seneca's practice of ‘metaphorical clusters’ is not explored, however, as G. does not discuss this passage.

One of the main ways Seneca's prose style is medicalised is via the notion of philosophy curing the soul through painful cutting and cauterising (191–8). The critique of Stoic style as ‘innumerable pinpricks’ is put to both literal and figurative use by Seneca (33, 197). The pointillist style of his prose serves as needles to shape and improve the soul. Pain is a key means for moral progress. This focus on the cognitive and curative value of pain here sits uneasily with G.'s earlier point that the pre-emotions elicited by literature allow for painless contemplation.

In the final pages, G. offers a selective exploration of two types of metaphors: architectural and military. As examples of the former, G. looks at how Seneca's descriptions of the homes of Servillius Vatia (Ep. 55) and Scipio (Ep. 86) link their dwellings to their moral qualities. Vatia's villa presents ‘physical and moral decay’, while the description of Scipio's simple dwelling highlights ‘the importance of healthy tensional qualities that both the man and his house present in common’ (218). It could also be noted that Seneca includes himself and his own estate in this metaphorical mix. In Ep. 12, Seneca brings together the unexpectedly decaying state of one of his villas and his own advanced age. Following this connection between architectural structure and style, G. turns to Seneca's critique of the ‘drunken style’ and the criticisms he levels against Maecenas in letters 19 and 114 (219–22). In one of his dialogues, however, Seneca states that occasional drinking, even to excess, can be therapeutic and can serve as a source of literary inspiration (Tranq. 17.9–10).

The book's focus is primarily on passages from Seneca's Epistles. A few dialogues are not discussed at all, nor is De clementia. Questions of how Seneca's use of metaphors may vary depending on the addressee, e.g. Helvia or Lucilius, are not treated, nor is the topic of how Seneca's use of the same metaphor may change over time, such as the designation of the soul as a king in De clementia (1.4.1–2), to which he returns years later at Ep. 114.21–24. In sum, while this book is a welcome aid for the study of Seneca's metaphors, a more thorough and systematic investigation of the corpus would have made it a stronger contribution.