Published in the series Lingue e Letterature of Le Monnier Università, a major Italian educational publisher, this book is an insightful and exhaustive investigation of the rainbow in Greco-Roman thought. Bonadeo (hereafter B.) should be commended on three grounds. First, she integrates literary, scientific, and material evidence seamlessly. Second, she contextualizes Greco-Roman concepts within a global anthropological context. Third, she elucidates non-canonical texts, from Hittite inscriptions to Hellenistic scientific treatises. The book consists of a brief introduction (1-3), the body of the analysis (4-222), eight plates (225-232), a bibliography (233-245), and indexes of ancient and modern authors (247-259). It is clearly divided into two parts of equal length, the first (4-123) discussing the representation of the rainbow in Greco-Roman literature and art (‘Mito’), the second (124-216) surveying parallel scientific treatises on its origin, optical geometry, and color ( ‘Natura’). However, B. simply divides the book into four chapters, each chapter consisting of several sections, and I follow here her own structure in summarizing the work.
Chapter 1 examines the personified Iris from a mythological and literary perspective. Tracing the earliest genealogy of Iris in the Theogony, B. demonstrates that Hesiod already encapsulates the basic characteristics of the rainbow (humidity, luminescence, and speed) to be found in later literature. Through a survey from Hesiod to Apollonius Rhodius, B. establishes a connection between Iris, eirein (to speak), and eris (quarrel), and argues for Iris’ extended dominion over messages, transitions, rites of passage, and even the Underworld (4-15). B. then turns to the tasks of Iris in the Iliad [2.786, 3.121, 5. 352, 8.397, 11.185, 15.53, 24.143 etc.], which are markedly different from Hesiod’s naturalistic and religious attributes. Homer’s Iris is a robust character who chooses her own form (visible, invisible, or disguised), edits her assigned messages, affects emotionally her human or divine interlocutors, and is particularly loyal to Hera. This evolution of Iris’ prerogatives is confirmed by the material record (mainly Archaic and Classical vases, illustrated in the back), which presents Iris as an attendant of the gods in various ritual or celebratory contexts (15-36). B. also explores Iris’ sexual potential as suggested in her delegation to Boreas and Zephyrus [ Il. 23. 192], and to the birds in Aristophanes’ homonymous comedy . This is a tentative thesis, but B. strengthens it through a convincing reading of various vase paintings, featuring a beleaguered Iris among harassing satyrs and centaurs. Examination of the scant epigraphic record suggests little or no evidence for cultic practices dedicated to Iris (36-44).
Turning again to literature, B. shows that at the end of the Iliad [24. 77], Iris is already supplanted by Hermes as the messenger of the gods. Zeus encumbers Hermes with the additional task of protecting humans, beginning with Priam in his journey to Achilles’ tent. Marginalized by Hermes, Iris disappears entirely from the Odyssey. B. claims that this substitution can be explained by a historical process in which Iris is gradually severed from her naturalistic origins as the rainbow ( iris), because of developments in physical epistemology. Deprived of a religious-cosmological significance, Iris is then reduced to a literary figure. Early 5th century vases depicting Iris and Hermes together support B.’s claim on the shift of authority between the two gods (44-53). B. argues that Roman literature further develops the Greek division between iris and Iris, while simultaneously reconnects the two in different ways. Beginning with Vergil [ Aen. 4. 693-715, 5. 605-610, 9. 2-22], Roman authors, from Ovid and Statius to Seneca and Macrobius, present the rainbow ( arcus) variously as Iris’ route from heaven to earth, as her girdle, her veil, or her mantle. Developing the Greek idea of Iris’ independent agency, Romans depict her as a self-motivated, and not entirely benevolent, character (53-66).
B. then sketches a visual composite of Iris, based on both literary and iconographical records. Pottery ranging from Cyprus and Greece to Italy and Sicily suggests artistic freedom regarding the ambiance of the goddess. Variously equipped with wings (on the back or feet), sandals, kerykeion, girdle, hat, flowing hair, youth/virginity, long or short tunics, running, flying, or standing in attendance of rituals (e.g. at the marriage of Peleus and Thetis), Iris is often confused with other minor goddesses (Nike, Hebe, Eos, and Eris). While such ambiguity can be resolved through a closer look at Iris’ habitus and context, identification beyond doubt depends on the (rare) inscription of her name in the visual medium (67-76).
A short second chapter (77-88) discusses the etymologies and definitions of the Greek lexemes Iris/ iris and its Latin equivalents Iris/ arcus/arquus. B. embeds these words in the context of Indo-European and non Indo-European languages. She notes that Romans prefer arcus/arquus (segment, bow) to the transliteration of the Greek iris, which is considered a more erudite word. This divergence is further evidence that the Greek iris retains a distant memory of the religious (Hesiodic, Homeric) origin of the rainbow. Conversely, the Latin arcus/arquus indicates a scientific and intellectual development in which ‘segment’ and ‘bow’ describe the natural phenomenon, while Iris remains a literary and fictional character.
Chapter 3 discusses the physical, emotional, and ritual connotations of the rainbow in Greek and Roman culture, providing ample comparanda from other cultures. B. claims that the modern association of the rainbow with tranquil beauty and meteorological resolution originates in Judeo-Christian mythology, particularly in the appeasing presence of the rainbow after the deluge in the Genesis [ Sept. 9.12]. On the contrary, Greek and Latin literature indicates plainly that the rainbow is a bad omen, predicting natural or social disasters. Surveying these texts that blend scientific, experiential, religious, and superstitious elements, B. explicates the ominous associations of the rainbow on the basis of the ancients’ agricultural dependence on good weather for survival and peace (88-98). B. embellishes her analysis with anthropological and folklore research ranging from South Africa, New Zealand, and Japan, to France, Germany, and Britain, to show that worldwide superstitions concur with Greco-Roman beliefs, on a similar ‘agricultural’ rationale (98-115). B. then turns to the vocabulary of rainbow colors. She notes the prevalence of red and its cognates (porfuros, purpureus, picta ferrugine, luce rubentem , etc.), and the perception of the rainbow as three-colored (red, green, and blue). These observations introduce an incisive discussion regarding modern versus ancient color perceptions, and the evolution of color theories through the 19th and 20th centuries. B. delineates three principles dominating Greco-Roman color perception: first, the combative coexistence of the emissive and admissive models of vision (the eye emits, or admits, visual rays); second, ancient chromatic vocabulary privileges color luminescence over color tone; third, the belief that all colors originate from a (chemical, physical, or illusory) ‘mixture’ of black and white in various proportions. B. argues that because the color red appears more luminous than green or blue, the ancient descriptions of the rainbow as ‘reddish’ probably reflect its radiant brilliance rather than a singularly perceptible color. She also remarks wisely that poetic license and literary diction are not reliable sources for ‘scientific’ realism (115-123).
This observation leads to the second part of this study, Chapter 4, which examines scientific rainbow theories from Aristotle to the Younger Seneca. Since B. analyzes technical terminology from optical theory, geometry, physics, philosophy, and doxography, illustrating these scientific theories with multiple graphs, it is difficult to do her detailed and learned arguments justice. B. devotes her largest section (124-178) to Aristotle’s rainbow disquisition in his Meteorologia [371b21-377a25], which dominates the ancient conceptualization of the rainbow. Justly calling Aristotle’s account a puzzle, B. argues that the structural, thematic, and verbal difficulties of this text can be attributed variously to the vexed manuscript tradition, to the loss of the original diagrams illustrating the optics of the rainbow, to subsequent revisions reflecting later scientific breakthroughs, and, ultimately, to Aristotle’s own uncertainties about the elusive nature of the rainbow. B.’s lucid exposition of the main points and problems of this text can be roughly summarized as follows:
a) Aristotle abandons the ‘physical’ cause he provides for all other meteorological phenomena, that is, the mixture of dry and humid exhalations ( anathymiaseis). Instead, he adopts abstract geometrical theorems to explain the rainbow.
b) He rejects the admissive optical theory promoted in De Sensu and De Anima for the emissive model of visual rays, and he oscillates between defining these rays as either physical or as geometrical entities. In the same vein, his rainbow narrative falls into two sections: the first explores the rainbow primarily as a physical entity, the second as an optical-geometrical one.
c) He defines the rainbow as circular, created by the anaklasis (reflection) of the round sun on a dark cloud, whose tiny raindrops act as mirrors. Because vision functions only above the horizon, the visible part of the rainbow can never exceed a semicircle, the length of its segment depending on the height of the sun.
d) The true rainbow colors are three (red, green and blue/violet), in descending order of brilliance, created by the ‘mixture’ of sunlight (white) and cloud humidity (black). A band of yellow/orange between red and green is an optical illusion created by the adjacency of these two colors, and not the result of physical anaklasis.
This last point reintroduces and elaborates on the fundamental differences between the ancient and modern perceptions of color, discussed in Chapter 3. B. concludes with a reading of a unique mosaic from 2nd century B.C.E. Pergamum. Featuring a three-colored rainbow and what seems to be black triangular clouds on either side, this ‘unrealistic’ image is influenced not by empirical observation but by the ambient scientific discussion around the Meteorologia. B.’s extensive elucidation of the inscrutable Aristotelian text is highly commendable, especially because she painstakingly reconstructs from Aristotle’s description the accompanying graphs, which are now lost. The incongruities, repetitions, and optical-geometrical impossibilities of these reconstructed figures confirm B.’s argument about the problematic nature of our text.
B. then summarizes rainbow theories predating and postdating this dominant narrative, all bearing clear marks of their Aristotelian debts and influences (179-216). In sections ranging from 1 to 5 pages, B. presents the views of Anaxagoras, Xenophanes, Anaximenes, Metrodorus of Chios, the Pythagorians, Poseidonius, Apuleius, Pliny the Elder, Plutarch, Pseudo-Plutarch, Aetius, Ammianus Marcellinus, Epicurus and Lucretius. These theories combine empirical observations, mystical beliefs, superstitious fears, philosophical principles, optical geometry, magical arithmetic, doxography, and even folktales. B.’s eloquent analysis is particularly valuable to those unfamiliar with the impressionistic character of ancient science, which often baffles the modern mind. At the same time, B. attends to the narrative aspects of these texts, and particularly to how the specific socio-historical context of each author informs his rainbow narrative. For example, in the Ammianus section, B. shows that the historian implicitly presents the rainbow as an ominous symbol of Julian the Apostate’s imperial oppression (195-196).
Finally, and quite symmetrically with the beginning of the chapter, B. discusses Seneca’s rainbow section in the Naturales Quaestiones 1.3-8 (201-216). Her detailed treatment corresponds to Seneca’s own ample investigation, which he aimed to be comparable to, and distinctive from, that of Aristotle. Accordingly, the defining characteristic of Seneca’s narrative is the complete absence of technical language, geometrical or otherwise. In its place, Seneca’s narrative features an influence of doxography, the rhetorical structure of a controversia, and Stoic moralism. B. explains these elements in the context of the larger agenda of the Senecan opus, in which epistemological primacy is given to ethical philosophy. In the Senecan worldview, sciences are merely ancillary to the development of the sapiens and his journey towards virtue (203). For example, responding to Aristotle’s tenet of the rainbow as a reflection, Seneca maintains that the rainbow is indeed a deforming reflection of the sun on a mirroring cloud [ Nat. 1.4.1, 1.5.13, 1.6.2]. However, Seneca’s discussion of mirrors soon turns into the moralistic fabella of Hostius Quadra [ Nat. 1.16], who allegedly used magnifying mirrors in his bedroom to satisfy his sexual perversions. Consistently attuned to narrative strategies, B. notes Seneca’s construction of a disagreeing interlocutor. In the manner of a controversia, this imaginary objector provides Seneca with a rhetorical foil and the opportunity to elaborate on his own arguments. In the brief ‘Conclusive Reflections’ (217-222), B. summarizes the trajectory of the rainbow in the Greco-Roman imagination, alternating between mythological personification and natural phenomenon. This conclusion also introduces briefly (and rather unexpectedly) surviving lexemes and connotations of the rainbow in the disciplines of anatomy, mineralogy, and botany.
This is, by all accounts, an excellent book. It makes convincing and seemingly effortless connections among such diverse fields as Homeric criticism, Archaic pottery, pre-Socratic philosophy, comparative anthropology, Hellenistic science, optics, geometry, Roman philosophy, and modern mineralogy. B. supports her wide range of sources with a varied and current bibliography, which also includes items from the 19th century. I am especially impressed by B.’s discussion of literature written in Modern Greek, which is notoriously difficult to obtain even in European libraries. The book is virtually free of typographical errors. I only noticed a circumflex above a Greek tau (n. 116). The handsome plates at the end illustrate aptly the iconographical development of the anthropomorphic Iris in the Archaic and Classical eras. Because B. frequently discusses art, one wishes for more plates than the existing eight. Yet this absence reflects editorial rather than authorial choices.
My only difficulties with this book are of a technical nature. The cross-references, for instance, are not always helpful. Many footnotes in the first part read simply ‘see below chapter 4,’ ‘see below,’ or ‘see above’ (n. 17, 133, 140, 201, 256, 260), while others point to specific pages (e.g. n. 215, 222, 275, 281). This is especially inconvenient in the first part, since many issues that B. discusses in a literary context (e.g. the rainbow color) are later examined from a scientific point of view. Also, the inclusion of technical vocabulary in the index would make cross-referencing between literature and science much easier, and the second part more accessible to the non-specialist. However, these minor structural quibbles do not detract from this first-rate book. Anyone interested in the rainbow, which still captivates the eye of the beholder, will find in B.’s book a keen, exhaustive, and imaginative investigation. Her treatment of the rainbow as both a natural and a literary phenomenon reminds the reader that the ancient mind was alternatively terrified and fascinated by the physical world, a far cry from the demystification of the Cosmos by our modern technological progress.