Divining Nature

Front matter

Divining Nature

Aesthetics of Enchantment in

Enlightenment France

II. Illustrations

Charles Le Brun, Expression of admiration

(wonder) with astonishment

. Jacques de Sève, Beaver (castor), from Buffon’s

Histoire naturelle

Jacques de Sève, Beaver skeleton, from Buffon’s

Histoire naturelle

. François Boucher, Pygmalion and Galatea, 1767

Piero Bonifazio Algieri, model of scenery for the finale of Rameau’s Dardanus, c. 1760

. Robert Bénard, Theater machinery (Machines de théâtre), from

Diderot and D’Alembert’s Encyclopédie Claude-Joseph Vernet, A Harbor in Moonlight, 1787

Claude-Joseph Vernet, A Storm on a Mediterranean Coast, 1767

. Jean-Michel Moreau le jeune, illustration from Bernardin de

Saint-Pierre’s Voyage à l'Isle de France, 1773

. Louis Lafitte, illustration from 1806 edition of Bernardin de Saint-Pierre’s Paul et Virginie

Claude-Joseph Vernet, The Death of Virginie, 1789

47 59

153 167 x Illustrations

12. Pierre-Paul Prud’hon, illustration from 1806 edition of

Bernardin de Saint-Pierre’s Paul et Viriginie 13. Étienne-Maurice Falconet, detail from Divine Glory, 1759

14. François Gérard, Ossian Evokes the Phantoms on the Banks of the Lora, 1801

15. Anne-Louis Girodet, Fingal Mourning Over the Body of Malvina, 1810

16. Jean Auguste Dominique Ingres, Ossian’s Dream, 1813

17. Anne-Louis Girodet, Ossian Receiving the Ghosts of the French Heroes, 1802

169 194

Acknowledgments

HIS book began with my interest in the marvelous. I never suspected Ti would take me down so many garden paths, however, and I have incurred many debts along the way. I would like to thank the members of our Eighteenth-Century Interdisciplinary Salon, past and present, who individually and collectively responded to various parts of this project as it evolved, particularly our founder, Rebecca Messbarger, as well as Pannill Camp, Charly Coleman, Alexandre Dubé, Matt Erlin, Minsoo Kang, Kristina Kleutghen, Wolfram Schmidgen, Annie Smart, Alexander Stefaniak, and Mark Valeri, who have been known to forego sleep and to brave storms for the sake of our discussions. Carolyn Abbate’s NEH Summer Seminar at Princeton University prompted me to consider opera in terms of performance and reception as well as libretto and score. I am grateful for the support of the Center for the Humanities at Washington University in St. Louis, where I was a Faculty Fellow for a themed focus on the subject of affect, and the National Endowment for the Humanities, which arrived at a critical juncture and allowed me to finish my book.

A tribute to those scholars who have had a formative influence upon my thought can be found in these pages. My research and writing would not have been nearly as rewarding without Eric Gidal’s and Anne Vila’s invaluable recommendations, references, and encouragement. Jean Allman, Daniel Brewer, Charles Dill, Paul Michael Liitzeler, John Lyons, Javier Moscoso, Mary Sheriff, and Karyna Szmurlo all generously engaged with my work at crucial moments. I owe special thanks to Harriet Stone, who never lost faith xii Acknowledgments in my vision. Numerous friends, colleagues, and mentors, whether wittingly or un-, provided necessary reassurance and fruitful suggestions or proved willing to lend an ear, including Juliette Cherbuliez, Andrew Clark, Andrew Curran, Talia Dan-Cohen, Lynn Festa, Seth Graebner, Chloé Hogg, Anca Parvulescu, Gerald Prince, Jean-Marie Roulin, Scott Sanders, Elzbieta Sklodowska, Joanna Stalnaker, Helen Thompson, and Amy Wyngaard. I greatly appreciate the dedication of my research assistants, Maëlan Gaucher, Anne Seul, and Dawn Mohrmann, who undertook numerous reconnaissance missions on my behalf, sparing me from having to venture yet further afield. I am also delighted to have had the opportunity to participate in the lively, collegial exchange at the Bloomington Eighteenth-Century Studies Workshop “Falsehood, Forgeries, Fraud: The Fake Eighteenth-Century” and the Folger Workshop “The Languages of Nature: Science, Literature, and the Imagination.”

I am profoundly grateful for Emily-Jane Cohen’s admission that she shared my affinity for the marvelous upon expressing initial interest in the project—providing me with an ideal reader—as well as for Erica Wetter, Kate Wahl, and Faith Wilson Stein’s expert guidance throughout the editorial process. I could not have wished for more perceptive outside readers, who intuitively grasped the scope and purpose of my book and helped me to fulfill them. I also wish to thank my previous editors, journals, and presses for permission to draw on my published work: “Music, Passion and Parole in Eighteenth-Century French Philosophy and Fiction,” in The Edinburgh Companion to Literature and Music, ed. Delia da Sousa Correa (Edinburgh: Edinburgh University Press, 2020); “Songs of Sorrow: Bardic Women in Girodet, Ossian, and Staél,” Eighteenth-Century Studies 52.2 (2018): 159- 65; “The Spectacle of Nature in Paul et Virginie: Natural History, Opera, and the Novel,” Forum for Modern Language Studies 48.2 (2012): 149-63; “Marvelous Machines: Revitalizing Enlightenment Opera,” Opera Quarterly 27.1 (2011): 66-93; and “From Myth to Religion in Ossian’s France,” in The Super-Enlightenment: Daring to Know Too Much, ed. Dan Edelstein (Oxford, UK: Voltaire Foundation, 2010).

Finally, I could not have persevered in this endeavor without my family, which remains my greatest source of inspiration and moral support. My

Acknowledgments xiii parents, James and Olivian Boon, fostered the many varied interests featured in these pages—nature, philosophy, literature, opera, art, and religion—and my sister, fellow scholar, and confidante, Jessica Boon, offered vital sources, conversation, and perspective along the way. My husband, Lionel Cuillé, shared the rather visceral moments of blindness and insight, melancholy and enthusiasm that characterize my writing process, and my children, Elena and Rémi, accompanied me wherever my research led, at home or abroad, geographically or conceptually, enabling me to appreciate the journey as well as the destination. I dedicate this book to you, with thanks and admiration.

Divining Nature

Introduction

The Spectacle of Nature e Spectacle de la nature, by the Abbé Pluche, rapidly became an En-

lightenment best seller that both revealed and fostered a widespread interest in natural history. A richly illustrated, eight-volume philosophical dialogue serially published in the years 1732-1750, Pluche’s magnum opus was perhaps an unlikely candidate for such immediate and sustained success.! Predicated on a notion of intelligent design, it contributed to contemporary trends in natural philosophy and theology. Pluche discusses the implications of his title in the preface to his work: “We all enjoy the view of Nature’s exterior. The spectacle is for our benefit. By limiting ourselves to it, we quite adequately discover the beautiful, the useful, and the true.” Content to contemplate the spectacle, Pluche resists the temptation to look behind the scenes.

But claiming to probe Nature’s depths, wanting to attribute effects to their particular causes, wanting to understand the artifice and the workings of the springs . . . is a hardy enterprise of uncertain success. We leave it to those geniuses of a higher order to whom it is granted to enter into these mysteries and see. For our part, we consider it more appropriate to restrict ourselves to the world’s external decor and to the effect of the machines that create the spectacle. . . . We can see that it has only been made so brilliant in order to pique our curiosity. Yet, content with a performance that sufficiently occupies our mind and our senses, we need not demand access to the salle des machines.?

Developing the analogy between the laws of nature and stage machinery— also known as the merveilleux—Pluche elects to remain in the audience, subject to the illusion, rather than venture backstage in order to determine how the special effects are achieved.* This acknowledgment of the implicit limitations of reason and the senses, subsequently dubbed epistemological modesty, left open the question of whether to attribute these effects to nature or the divine. Evidence of this dichotomy can be seen if we compare this analogy to another famed evocation of nature’s spectacle, that of Bernard de Fontenelle, who likened nature to the opera in his 1686 Entretiens sur la pluralité des mondes habités (Conversations on the Plurality of Worlds). While Fontenelle, a philosopher, invoked the analogy to suggest the sufficiency of the laws of matter, Pluche, a priest, invoked it to demonstrate the existence of God.

The notion of nature as spectacle, like that of nature as clock or book, dates back to the Greek philosophers’ initial forays into natural history. Christian theologians reinforced this imagery over the centuries, for the perfection or complexity of such creations seemed to imply the existence of a creator. Whether clock, book, or spectacle, the concept of nature harbors an inherent tension, for it is implicitly likened to its opposite: artifact, artifice, or art.* In their analyses of the emerging language of scientific inquiry, Steven Shapin and Robert Markley interpret the “constitutive metaphor” of the two books—Nature and Scripture—in the context of late seventeenth-century physico-theology, which informed the methods of the Royal Society, “justifying natural philosophy as a means to a theological end.”* Jessica Riskin explores the resonance of the clockwork metaphor, primarily associated with late seventeenth-century mechanism yet employed over the centuries to suggest either nature’s agency (organized) or lack thereof (designed).° Such figurative language arose, Tita Chico suggests, as natural philosophers considered how to understand and represent the natural world.’

Early-modern characterizations of nature as book, clock, or spectacle were not unrelated. In The Excellency of Theology, Robert Boyle describes nature as a book either without an ending, whose ending is concealed, or whose ending will never be reached; a cliffhanger of sorts. Larry Laudan traces the heritage of the clockwork metaphor from René Descartes through Boyle to John Locke, all of whom emphasize the fact that, so long as a watch remains closed or a clock is seen from afar (Locke’s famous clock at Strasbourg), we can but speculate as to the arrangement of its inner workings. Yet, as Laudan notes, Descartes ultimately “fell victim to his own metaphor,” for just as one can presumably read to the end of a book, one can also in most cases open a watch or a clock to examine its inner workings, which is how the metaphor came to be understood. The comparison of nature to spectacle, however, preserved the notion of an area in the wings, backstage, or behind the scenes (dans les coulisses) that could not be perceived from the audience. It did so, moreover, in an era when spectators were removed from the stage and relegated to the audience in order to enhance the illusion. The invocation of the analogies of the book and the clock by those who wished to posit the limits of human understanding thus suggests a certain carryover rather than a sharp distinction between what Riskin refers to as the “theological mechanists” of the Royal Society and the “sentimental empiricists” of the French Enlightenment, who subsequently privileged the notion of nature as spectacle. While the phrase “book of nature” remained prevalent in eighteenth-century Britain, the phrase “spectacle of nature” outstripped it in eighteenth-century France dating from the publication of Pluche’s bestseller.’

The characterization of nature as spectacle carries certain connotations that the other expressions do not. First of all, it shifts the emphasis away from the implied creator toward a structure of representation and reception, for while we are familiar with references to the author of nature or the great clockmaker, we rarely if ever hear of the divine dramaturge. Whereas the theatrum mundi posited the gods or God as spectators of humanity, the spectacle of nature casts humanity not as actors but as audience. While both clock and spectacle consist of moving parts—springs, cogs, wheels— spectacle is far more dynamic; though scripted, choreographed, and directed, it is nevertheless subject to the vagaries of performance. In the early-modern context, spectacle was generally understood to refer to the sung rather than the spoken theater, moreover, involving the collaboration of the arts and technology to produce a multisensory experience. It also adds an af fective dimension, for spectators both comprehend (intellectually) and react (emotionally) to what they perceive. The construct thus proved equally useful in the realms of epistemology and aesthetics and was particularly suited to the widespread tendency to “[view] life in terms of spectator-spectacle relations” that David Marshall attributes to the period." Finally, spectacle effectively subdivides nature into its visible and invisible (or occult) components, the former accessible to the senses, the latter beyond their reach, offering little to no assurance that its “secrets” can be discovered. By the turn of the eighteenth century, natural philosophers and theologians were inclined to agree that first causes were providential, material, or difficult to impossible to determine. In his sweeping study of the period, Jonathan Israel remarks that “apparent ‘design? as Diderot was to confirm, could after all be just as convincingly ascribed . . . to Nature’s self-formation or evolution, as to the Providence of Newton.””” Spectators, regardless of their persuasion, could observe, admire, analyze, and interrogate the design, in other words, without ever venturing to settle the question of whether it was intelligent. Whereas Riskin characterizes Pluche’s Spectacle de la nature as the last gasp of a “brute-mechanist argument-from-design tradition,” I take this work as my point of departure, demonstrating how the sentimental empiricists who wrote in Pluche’s wake deployed this metaphor in the interest not of penetrating nature’s mysteries or exposing its mechanisms but of respecting its integrity while exploring its vitality, adopting the attitude that Pierre Hadot describes as Orphic.f

The notion of spectacle in eighteenth-century France had something of a bad rap. Considered a frivolous means of diversion or entertainment, it was seldom taken seriously. Associated with the rococo aesthetic of distraction rather than the neoclassical aesthetic of absorption, it was, then as now, presumed to occasion passivity, dissipation, or dissention in the audience. Connoting both artificial and superficial, the term spectacle was usually prefaced by or presumed to imply the qualifier mere. This reputation, as we shall see, was hardly deserved. We might ask, however, whether a spectacle is still a spectacle if there is no one to see it. The notion of spectacle implied, in other words, the existence of a spectator. Joseph Addison and Richard Steele’s Spectator—a periodical that ran in the years 1712-1713, inspiring Pierre de Marivaux’s 1721-1724 Le Spectateur franc¢ais—broadened this role from a member of an audience to a member (and observer) of society. A successful playwright, Marivaux was keenly aware of the role of the spectator, which he explored at great length in the character of Jacob, a peasant freshly arrived in Paris from the provinces, who learned to climb the social ladder by changing costume and forms of address, eventually receiving his comeuppance in the foyer of the Comédie. Like the Baron de Montesquieu’s Rica and Francoise de Graffigny’s Zilia, who respectively hailed from Persia and Peru and viewed Parisians, their language, and their mores with an objective eye, Jacob saw Parisians for what they really were. Jean-Jacques Rousseau likewise arrived in Paris from provincial Geneva only to decry what he found, while Denis Diderot’s eponymous character, Rameau's nephew, exposed the social posturing at the heart of every economic transaction. Sébastien Mercier and Nicolas-Edme Restif de la Bretonne, who observed Paris by day and by night throughout the tumultuous years of the Revolution, round out the list of fictional and factual spectators who broke down the boundaries between stage and street, unmasking the theatricality inherent to eighteenth-century society. Critics who have taken an interest in these developments invariably expand the scope of their inquiry beyond the stage, focusing on the debates that raged among spectators at the Comédie-Frangaise and the Opéra, on the spectator function that emerged in theories of art, law, and politics, or on the spectator as observer and critic of society. I build on these studies yet redirect our gaze toward the spectacle of nature, focusing on figures who view nature from what Marshall calls an “aesthetic perspective.”

Among the first to adopt an aesthetic perspective was Addison himself, who anticipates several of my lines of inquiry in Spectator nos. 411-21, dedicated to the pleasures of the imagination that arise from visible objects and their artistic representation, whether present or absent, factual or fictitious. These include “histories, fables, and contemplations of nature”! While Addison claims that nature is most effective when it resembles art, as is art when it resembles nature, certain fictions depart from nature, employing what he calls, after John Dryden, the “fairy-way of writing,” for fiction takes not only the natural world as its province but also worlds of its own design. From here, Addison segues into a discussion of related genres, including history, natural philosophy, and travel narratives. Foremost among these are texts written by the “authors of the new philosophy,” of whom he states: “There is something very engaging to the fancy, as well as to our reason, in the treatises of metals, minerals, plants, and meteors; but when we survey the whole earth at once, and the several planets that lie within its neighborhood, we are filled with a pleasing astonishment, to see so many worlds, . . . and confounded with the immensity and magnificence of Nature.” The evocation, discovery, and representation of other worlds is thus common to natural philosophy and fiction. I propose to investigate what transpired when those accustomed to honing their powers of observation on the natural world felt obliged to engage in philosophical speculation or inclined to indulge in the pleasures of the imagination.

ENLIGHTENMENT DISENCHANTMENT The Enlightenment remains widely associated with the rise of scientific progress and the loss of religious faith, a dual tendency that is thought to have contributed to the disenchantment of the world. In his 1917 lecture “Science as a Vocation,” Max Weber nostalgically characterizes the “inward calling for science” as “passionate devotion.” What was once a matter of enthusiasm or inspiration has become a matter of calculation, however, relying on the mind rather than the heart and soul. Though “inspiration plays no less a role in science that it does in the realm of art,” the affinity between the two ends there, for science is linked to progress. Charting the growing division between science and religion, Weber famously declares: “The fate of our times is characterized by . . . the disenchantment of the world,” which has come to define the modern condition. Borrowing this phrase in Dialectic of Enlightenment, Max Horkheimer and Theodor Adorno attribute the loss of spirituality to the rise of experimental philosophy, asserting: “The program of the Enlightenment was the disenchantment of the world; the dissolution of myths and the substitution of knowledge for fancy.”!? The Enlightenment and modernity have been indelibly associated with disenchantment ever since.

Recently, scholars have started to contest the persistent pairing of the terms modernity and disenchantment in the history of science, religion, and mass culture. While Bruno Latour characterizes moderns as those who view disenchantment as a necessary evil and antimoderns as those who view it as a catastrophe, he himself insists that this apparent break with the premodern past is illusory (the amodern view).”° Tracing the genealogy of what he boldly dubs the “myth of disenchantment,” Jason A. Josephson- Storm argues that it began not with the scientific revolution, as has often been claimed—neither Descartes, nor Francis Bacon, nor Isaac Newton eschewed religion and the occult—but rather with the selective reading, reception, and representation of their work.” Religion and the occult were not eradicated but merely displaced, he contends, for “if Diderot exiled God, it was in order to enchant nature with powers previously reserved for the divine”? Thus, as Darrin McMahon effectively puts it, “the progressive disenchantment of the world was accompanied from the start by its progressive re-enchantment.””*

While a number of scholars have begun to resist disenchantment’s association with modernity, few have returned to the purported origin of the problem, questioning its attribution to the Enlightenment. Recent antirationalist interpretations of the era, including those of Jesse Molesworth, Sarah Tindal Kareem, and Courtney Weiss Smith, have focused primarily on British philosophy and literature. Yet France was better known for its rationalism, materialism, and attacks on superstition, fanaticism, and the abuses of organized religion. Its association with disenchantment is therefore harder to shake. Charly Coleman’s examination of resacralization as a countercurrent to the secularizing process in eighteenth-century France constitutes a significant step in this direction.” I investigate the fate of the marvelous in the age of reason and sensibility. My study challenges Horkheimer and Adorno’s assertion that the pursuit of knowledge led to the domination of nature and the denunciation of illusion for fear of the unknown, denying the existence of an absolute rift between science, art, and religion. I therefore provisionally retain, in order to reclaim, the embattled term Enlightenment. The notion of disenchantment,

I contend, is fundamentally at odds with the aesthetic aims of the period, which prompted audiences to interrogate, test, and cast beyond the limits of reason and the senses. The figures in my study, to the contrary, both sustained the possibility of and helped establish the epistemological and aesthetic preconditions for belief, whether in revealed, discovered, fictional, or experiential truth.

In their introduction to The Re-Enchantment of the World: Secular Magic in a Rational Age, Joshua Landy and Michael Saler delineate three possible approaches to the “problem” of disenchantment. The binary approach suggests that rationalism and secularism relegated enchantment to the margins of popular culture whereas the dialectical approach suggests that rationalism and secularism became a dangerous and deceptive form of enchantment themselves. Yet disenchantment, they contend, need neither displace nor become its opposite. By the same token, enchantment need be neither regressive nor insidious. They therefore promote the antinomial approach, characterizing modernity as harboring “fruitful tensions between seemingly irreconcilable forces and ideas”: secularism and superstition, science and religion, reality and imagination, reason and enchantment. My book contributes to this third approach. I do not, however, insist quite so strongly on secularity as a means of recovering what was “formerly found in contemplation of the divine.””° As my study suggests, both believers and nonbelievers participated in the observation and representation of nature’s marvels irrespective of their creed, a compatibility facilitated by the conception of nature as spectacle. The “void” they sought to fill, I maintain, was occasioned not by the absence of God so much as that of the gods during a momentary hiatus when the inadequacy of the pagan marvelous was widely acknowledged but a viable substitute had yet to be found.

If we look up “Enchantment” in Diderot and Jean le Rond d’Alembert’s Encyclopédie, we find three definitions. One cites the Abbé Pluche, who identifies the etymological origin of the term as “je chante” (I sing), used to refer to the ritual incantations pronounced to preserve or ensure the medicinal or magical properties of plants. Another extends this definition to any amulet or talisman used for healing purposes, particularly in natural medicine or religion, a practice common to philosophers and physicians.

The third, and most famous, to which I will return, associates the term with the opera, or “theater of enchantment,” whose cornerstone was the marvelous (merveilleux). If we consult the entry “Marvelous,” however, we open up a veritable Pandora’s box, or can of worms. Defined as the intervention of the gods in the epics of Homer and Virgil, or personified passions in modern poetry, marvelous occurrences are glossed as bold but plausible fictions. Yet the use of the marvelous must be rethought, the anonymous author of the entry avers, for the intervention of the gods, which seemed perfectly plausible to the Greeks and Romans, no longer was to the French. To each time and place its own marvelous, he asserts, making an exception, significantly, for natural phenomena, which he deems universal. The Greeks and the Romans did not borrow their marvelous from elsewhere. It was therefore up to the French to settle on a variety of marvelous to which they could lend credence, which should ideally be informed by their prevailing system of belief 2 The Christian marvelous was not yet considered a viable substitute, however, for its subject was too sacred, its virgins too modest, its devils too burlesque.” Milton alone had succeeded in this vein and would arguably not be rivaled until the full potential of the Christian marvelous was acknowledged toward the end of the century.*° Enlightenment France thus became the site not only of a crisis of language, as I have argued previously, but also of what we might consider a crisis of faith—a crisis that was less religious than aesthetic.* What we find in the treatises, prefaces, and press, in the encyclopedias, dictionaries, and supplements from the era, is on the one hand a denunciation of the marvelous and on the other a quest to identify fresh sources of inspiration to improve its efficacy or approximate its effects. In the Supplément to the Encyclopédie, Jean-François Marmontel recounts how the encounter with the marvelous in nature led to the conception of the marvelous in the arts.

Philosophy is the mother of the marvelous and the contemplation of nature gave her the idea. She saw around her a multitude of marvels without any cause other than movement, which itself had a cause. She therefore said, “There must be a principle of strength and intelligence above and beyond what I can see.” This was the primitive, generative idea of the marvelous. This unique and universal cause that adhered to a simple law was too vast and imperceptible for the sages or the people. They divided it into a multitude of . . . agents modeled after us, which gave us the gods, the demons, the genies. . . . Nothing could have been more favorable to the arts.*”

Artists, Marmontel suggests, concoct agents responsible for phenomena that lie beyond the realm of human understanding that natural philosophers are unable to explain. The conception of the marvelous (or the supernatural) in eighteenth-century France was intimately linked to the understanding of nature (or the natural), with which I propose to begin. In the following chapters, we will encounter philosophers and artists who turn to the natural world and to alternative mythologies—notably found in the Middle East, the French tropics, and the Gallic past that espoused various forms of natural theology—in an effort to render the marvelous plausible. This did not mean that Greco-Roman mythology was indelibly replaced or displaced. Instead, it was harnessed, on occasion, for the purposes of exploring the new empirical, sensationalist, and vitalist philosophies, as we see in the deployment of the Pygmalion myth, or infused with a new spirit of conviction, as we see in the emergence of neoclassical history painting, the resurgence of epic poetry, and the reform of tragic opera in the course of the century. It thus both contributed to and benefited from the search for new sources of inspiration. The crisis of faith did not lead, therefore, to the systematic elimination of the marvelous in order to bring artistic productions into line with Enlightenment rationalism. Instead, it inspired experimental forays into alternate subjects, modes, forms, and spaces of representation, often predicated on the natural world yet infused with a sense of the marvelous that audiences found more plausible, probable, or possible and therefore persuasive. Faced with potential disenchantment, disillusionment, or demystification, philosophers and artists actively staved it off, seeking instead to induce and sustain a range of emotions traditionally associated with religion, including wonder, enthusiasm, melancholy, and the “sentiment of divinity.”

Introduction II

ENLIGHTENMENT SCIENCE

The notion of nature as spectacle gained currency as natural philosophers and theologians sought common ground for the observation and explanation of nature’s workings.’ The analogy lent itself particularly well to the shift from rational to experimental philosophy during what is commonly known as the scientific revolution. The novelty of the so-called new science lay in the conviction that our understanding of the natural world proceeds not from axiomatic or innate ideas but rather from sensory perception. This conviction, first articulated by Bacon, led natural philosophers to privilege observation and experiment over deductive reasoning. The advent of experimental philosophy as a practice is associated most famously with the debates between Boyle and Thomas Hobbes over the air pump. Boyle’s innovation lay in his attempt to explain observable phenomena, not in terms of posited underlying structures or systems but rather in terms of one another. He did so, as Steven Shapin and Simon Schaffer contend, by drawing “a crucial boundary between the experimental matter of fact and its ultimate physical cause and explanation,” reserving “fact” for recorded observations or experimental results and variously employing “theories, hypotheses, speculations” for the act of interpretation that consisted of surmising probable cause.** Hobbes’s dismissal of Boyle’s disinclination to read too much into the facts as “unphilosophical” attests to the novelty of Boyle’s approach, which was subsequently adopted by the Royal Society. Stephen Gaukroger describes this approach to scientific investigation as a horizontal rather than a vertical treatment of causation.”

Locke maintained this distinction between discrete levels of analysis in An Essay Concerning Human Understanding: cause and effect, primary and secondary qualities, the microscopic and the macroscopic, the first of which lies beyond and the second of which lies within the bounds of sensory perception.% The perception of relations between ideas—notably their agreement or disagreement—was for Locke the basis of all knowledge, which he subdivided into varying degrees of certainty from intuitive to demonstrative.*” Intuitive knowledge is the immediate perception of the relation between ideas, which if partial or limited takes the form of probable conjecture yet when entire or absolute approaches divine revelation.** Demonstrative, or rational, knowledge is the mediated perception of the relation between ideas through recourse to a third, analogous one, a process Locke called reason, which gives rise to probability.* The limits of our knowledge, or our inability to discern the causes of certain effects, oblige us to resort to analogical reasoning, which in turn leads to insight, or further discovery.*” Remarkably, Locke refers to the certainty produced by intuition as knowledge and to the probability produced by reason as faith, combating the common misperception that faith and reason are opposed.*! While epistemological modesty purportedly precludes positing what lies beyond the bounds of sensory perception, empiricism contains a stage that requires philosophers to do just that. Unlike rationalism, which is predicated on a process of deduction from axiomatic principles or maxims, empiricism begins with observation and experiment followed by an attempt to infer or induce the relations (causal or otherwise) among facts.