Opening with the Abbé Pluche's best selling Spectacle de la nature, the introduction distinguishes characterizations of nature as book, clock, and spectacle. Questioning lingering associations of the Enlightenment with disenchantment, it considers the fate of the marvelous in eighteenth-century France. Affective responses to nature's spectacle—traditionally associated with religion or religious fanaticism—including wonder, enthusiasm, and melancholy, were systematically linked to the faculties of reason, imagination, and memory that structured Diderot and D'Alembert's Encyclopédie. The introduction lays the groundwork for this study by surveying developments in Enlightenment science and aesthetics, particularly empiricism, sensationalism, vitalism, and the theorization of the sublime, traced not to Longinus but to Lucretius.

Taking Fontenelle's famed comparison of nature to the opera somewhat literally, Chapter 1 considers the representation of natural phenomena in the Comte de Buffon's Histoire naturelle and Jean-Philippe Rameau's opera Zoroastre, which coincided in 1749. Lorraine Daston and Katherine Park have argued that wonder gave way to a more scientific curiosity in the Enlightenment. This chapter demonstrates that Buffon and Rameau to the contrary sought to sustain the wonder of the reader/spectator when confronted with natural marvels on the page and the stage. Wonder constituted the affective counterpart to encounters with the marvelous, which Rameau's librettist Louis de Cahusac considered a defining feature of French tragic opera. The chapter likens plans for the improvement of special effects, the renovation of the opera, and the establishment of the National Museum of Natural History in the course of the century, designed to reconcile enlightenment and enchantment.

Denis Diderot and Jean-Jacques Rousseau were avid readers of Buffon's Histoire naturelle and active participants in the quarrels prompted by Rameau's operas. To date, scholarship has focused primarily on their theorization of physiological and moral sensibility. Chapter 2 investigates Diderot's and Rousseau's response to the spectacle of nature, focusing on the affinity between the inspiration of the artist and the identification of the spectator. Jan Goldstein has characterized "enthusiasm" and "imagination" as eighteenth-century smear words. These terms are recuperated in Diderot's writings on painting and the theater and Rousseau's writings on opera and the novel, however. Enthusiasm, like pity, necessitates a movement outside oneself that facilitates union with the other and the forging of the ideal model. The chapter concludes by considering the alternate forms of natural spectacle that Diderot and Rousseau envision in their writings.

Rousseau's protégé, Jacques-Henri Bernardin de Saint-Pierre, conceived of his Études de la nature as a complement to Buffon's Histoire naturelle. Chapter 3 traces the generation of his novel Paul et Virginie from his travelogue to its publication as the fourth book of his natural history. Bernard de Lacépède's Poétique de la musique provides a missing link between Bernardin's novel and its operatic adaptation by Jean-François Le Sueur. Reading Bernardin's natural history, full of advice for artists, alongside Le Sueur's essays on church music, full of tips for composers, reveals that author and composer both sustained and sought to foster mixed emotions in response to the spectacle of nature that led to the "sentiment of divinity." The chapter concludes with a consideration of French cathedrals, redesigned along lines reminiscent of the opera and the natural history museum in the course of the century.

France's frame of reference shifted northward when James Macpherson went in search of the Scots national epic, returning with poems attributed to the third-century bard Ossian. Though denounced as a hoax, Macpherson's reconstruction of a lost epic from surviving fragments has since been compared to scientific endeavors such as geology and cartography. Chapter 4 explores Macpherson's use of similes interrelating the natural and the spiritual realms and the relationship between melancholy and memory in the epics before turning to their favorable French reception. Both Napoleon and Germaine de Staël embraced France's northern heritage, hailing Ossian as the new Homer. Privileging northern melancholy over southern enthusiasm, Staël looked to the philosophical poetry of the north as the source of French spiritual regeneration. Ironically, anxieties about the epics' authenticity led to the establishment of the Académie Celtique and the science of folklore.

The epilogue considers E.T.A. Hoffmann and François-René de Chateaubriand's retrospective reflections on the marvelous in art and nature. Evidence that the marvelous survived the century can be found in the glories used to transport Greek gods, Christian angels, and Scots ghosts in opera, on altarpieces, and in history painting. The cognitive and emotional responses to the spectacle of nature, including wonder, enthusiasm, melancholy, and the "sentiment of divinity," which contributed to the theorization of the sublime, also pertain to current discussions of environmental aesthetics.