The minds of fish, the dreams and disposition of the angler, and the captivating paradoxes of the fisherman’s art: Virginia Woolf’s essay on fishing addresses the relationship between literature and the natural world, and the status of fishing as a moral, technical, and psychological exercise. In her essay Woolf reviews J. W. Hills’ classic fly-fishing guide, A Summer on the Test (1924), dwelling on the power of the text to transport the reader into the environment it evokes.1 Transpose these concerns to the open sea, and her words could delineate the world of Oppian’s Halieutica, a second-century ce Greek didactic epic in which fish and men, as well as poetry, politics, and pragmatism, collide before the reader’s eyes. In five hexameter books on fish and fishing, the Halieutica too sets out to ‘penetrate’ a shadowy aquatic domain, portraying the hopes, struggles, and character traits of both humans and the fish they pursue.

Part I of this book has explored the status of didactic poetry in the ancient world, arguing in Chapter 1 that generic conceptions of the close relationship between heroic and didactic epic represent less a definitional problem than a sphere of opportunity for ancient didactic poets, who often signal their affiliation to, and adaptation of, heroic as well as didactic traditions. Important too is the range of contexts in which both the ethical and the ‘technical’ content of the Homeric epics was taken seriously in the ancient world. Much of this book traces the permutations of these claims as they are refracted in the Halieutica. In Chapter 3, for instance, we saw that Oppian draws not only from didactic epic traditions but also from the address to the Muses and the Catalogue of Ships in Iliad 2 in order to foreground epistemological questions about the relationship between divine and mortal knowledge, immensity, and incapacity in his proem. Homeric approaches to the relationship between human and non-human animals will in turn be examined in Part III. As Chapter 2 has shown, moreover, Oppian emphasises the simultaneously sweet or pleasant and educational effects of his verse; these may be seen not as opposed but as intimately related facets of the poem. The work’s most ‘poetic’ elements, in other words, are often its most didactically potent, and the moral structure of Oppian’s marine world turns out to be deeply rooted in the traditions of hexameter epic.

Didactic poetry has fallen firmly out of favour as a contemporary genre: it is a literary form rarely used by modern authors and seldom read by the twenty-first-century public. A remark in Shelley’s preface to Prometheus Unbound (1820) offers one enduring explanation for its demise: ‘Didactic poetry is my abhorrence; nothing can be equally well expressed in prose that is not tedious and supererogatory in verse.’ Why write in verse, the argument runs, if one aims at clarity and pedagogical precision; conversely, why aim to communicate factual information if one values sublimity and the poetic imagination? A technical manual in verse fits the perceived role of neither poetry nor prose.

The opening verses of the Halieutica are rich and rewarding. They establish the poet’s authoritative first-person voice, the subject-matter and scope of the work, and the identity and significance of its addressee. Oppian also draws attention to his markedly anthropomorphic representation of sea-creatures, and to the poem’s Homeric pedigree: as we will see in chapter 8, fish are figured programmatically in these lines as quasi-Iliadic warriors, and the poet engages in learned and allusive Homeric commentary. In didactic terms these lines both align and distinguish the work from the traditions of Homeric epic. The first verb of the poem, ἐξερέω, is emphatically delayed and set at the start of the third verse; it announces the poet’s aims and associates him with the poem’s addressee Marcus Aurelius. At key transitional moments in the Halieutica, including the proems to each book, Oppian again invokes the emperor, always in highly laudatory terms, and sometimes alongside his son Commodus.1 These addresses draw attention to the poet’s relationship with his imperial patrons, as Chapter 11 will explore, and at the same time impose a structure on the poet’s body of information, outlining the organising principles, content, aims, and imagined reception of the work. This explicit relationship with an addressee is an authorial stance that immediately differentiates such poetry from the narrative conventions of heroic epic.

Several of the themes that have emerged in the exploration of guile and trickery in Chapter 4 – Oppian’s emphasis on the Odyssean qualities of fishing, as well as a fascination with short-sighted or impulsive behaviour and its evil consequences – take on particular force in the third book of the Halieutica, which turns from cunning to greed, and from fish to fishing. Fish, we are told, are inescapably σιφλός – deficient, lazy, gluttonous, blindly self-destructive –1 and the fisherman’s use of bait turns the creatures’ own appetites against them, exploiting their precipitous passions.

Analogy, this book argues, is the master trope of the Halieutica. The world of fish is illuminated through continual reference to other forms of life, both human and animal, and the poem demands that each be understood and evaluated against the other. Similes, metaphors, and comparisons pervade and structure the work, and the poet’s anthropomorphic language brings fish into the domain of the human, and vice versa. Metaphor and simile are figures constituted by subtle combinations of similarity and difference, however, and Part III of this book explores the ways in which the poem challenges its readers to determine the precise nature of the relationships it illustrates. Extended similes of course enjoy a privileged role in epic discourse, and Oppian frequently defines his didactic epic both through and against Homeric analogical practice, capitalising on the archaic poet’s interest in the similarities between human and animal life. Chapter 7 examines the extended similes of the Halieutica, focusing on the representation of fish in ‘battle’ as a mode of engagement with Iliadic narratives of war, as well as with wider questions about violence and power; Chapter 8 builds on this analysis to explore the manner in which the didactic poet draws on Homeric representations of the close relationship between human and non-human animals; Chapter 9 sets these debates in their contemporary contexts by exploring the poet’s radical blurring of the human–animal boundary.

Chapter 8 has argued that the close relationship between human and non-human animals in the Halieutica is modelled in part on the linguistic and thematic similarities that associate human and animal anatomy, behaviour, psychology, and habitat in the Homeric epics. We have seen that close attention to the relationship between the two domains is a feature of Homeric poetry discussed extensively by ancient critics, and to which the Halieutica draws attention with its very first word. Yet Oppian, I now show, goes further even than Homer in blurring the boundaries between the two realms; this chapter embeds this aspect of the poem in its contemporary cultural contexts, arguing that it speaks to a wider imperial Greek fascination with the relationship between human and non-human animals, above all in the ethical and erotic spheres.

The next two chapters expand on the issues raised in Chapter 7: Oppian’s detailed engagement with the similes and metaphors of the Homeric epics, as well as his evident familiarity with ancient literary-critical debates about these practices; the close thematic connection between sequences and clusters of images in the Halieutica; the perceived degree of similarity between humans and other animals; and the ethical dimensions of that relationship, including the desire for bloodshed. This chapter focuses on the poet’s reflective engagement with the representation of animals in the Homeric epics, while Chapter 9 explores the ways in which the poet speaks also to a contemporary imperial Greek interest in the status of (non-human) animals.

The Halieutica opens by representing the sea as a vast, impenetrable, and unpredictable environment, its myriad inhabitants both fascinating and baffling. As often in ancient thought, the sea is imagined to bring both terror and adventure, mortal danger and new frontiers. For Oppian this is also a realm that marks an epistemological boundary, and the start of the poem is structured by a tension between what can be known and what cannot. The sea is in part available to be catalogued and described, yet its limits lie tantalisingly out of reach, and its depths have yet to be conquered by man. Book 1 – which catalogues sea-creatures according to habitat (1.93–445), before discussing their mating practices (1.446–797) – is not structured according to the moral qualities that dominate the following three books; it is concerned less with the failings of fish than with delineating the environment in which these creatures live and breed.1 In placing weight on the unfathomable enormity of the sea, I argue, the poet writes his work into a didactic epic tradition that draws attention to the process of gathering and disseminating knowledge, foregrounding not only the possibilities but also the epistemological challenges generated by the drive to catalogue such an immense and daunting realm.

The Halieutica proclaims itself the product of a distinctively imperial age. The poem opens by invoking not the gods or Muses but Marcus Aurelius (1.3), who is addressed and praised, sometimes together with his son Commodus, in every book.1 The emperor is represented as a figure of near-divine status, a glorious leader for whom all mortal actions are carried out (3.6), whose power over the natural world is so great that even fish delight at being caught by him (1.70), and who has ushered in the just and peaceful conditions under which the poem has been composed (2.684). Oppian’s laudatory language underscores the majesty of the all-powerful and divinely favoured emperor.2 This divine favour seems far-reaching indeed: Marcus is frequently invoked or addressed in association with the gods,3 and the poet at times switches unexpectedly between the two, leaving the reader momentarily uncertain as to the identity of the (divine or human) βασιλεύς being invoked (1.73, 5.45).4