THE ENLIGHTENMENT’S ENTANGLEMENT with science is pervaded with ironies. The philosophes celebrated the scientific revolution, accepted its findings, and imitated its methods. They pushed its philosophical implications far beyond what the scientists themselves would have thought warranted. They tried to apply the scientific style of thinking to the regions of aesthetic, social, and political theory. But they discovered that, having eliminated the problem of God, they had burdened themselves with new difficulties, almost as intractable as the old.
In the age of the Enlightenment, that great time of discovery, consolidation, and triumphant popularizing, it did not take unusual perspicacity to recognize the scientific revolution as an extraordinary event. It was plain that this revolution was the most far-reaching upheaval the West had experienced since the Protestant Reformation, indeed more far-reaching: the discoveries of Galileo and Boyle and Newton were changing the world more drastically than it had been changed by the doctrines of Luther and Calvin. The spectacular intellectual conquests of astronomers and physicists made science interesting to many, and not to philosophes alone: the philosophes might think themselves privileged admirers, but in fact science had many other courtiers in the age of the Enlightenment; indeed, when Rousseau denigrated the sciences in his first Discours, it was the Jesuit Journal de Trévoux that defended them against this eloquent slanderer.
The philosophes welcomed the widespread passion for science—the mass of popular explanations of abstruse theories, the new scientific journals—but, as men of letters, they were also a little uneasy about it. In 1735 Voltaire, on a short visit to Paris from Cirey, complained that “verses are hardly fashionable any longer.” Now “everybody has begun to play at being the geometer and the physicist,” and as a result, “sentiment, imagination, and the graces have been banished. Someone who had lived under Louis XIV and returned to the world would no longer recognize the French; he’d think that the Germans had conquered this country. Literature is perishing before our very eyes.”1 Obviously literature was far from perishing—Voltaire was seeing to keeping it alive—and the graces were still in their place, but Voltaire’s comical lament testifies to a widespread and often serious interest in the sciences.
In fact, the scientific revolution, far from challenging poetry, enriched it; it invaded Western languages and literature with its terms, metaphors, and themes. Critics of the new learning were no less obsessed with scientific language than its admirers; Pope and Swift at the beginning, Blake at the end of the eighteenth century tried to damage the new “mechanistic philosophy” by punning on its technical terminology and ridiculing its practitioners. In vain: their Humanist’s fear of science was eclipsed by the confidence of its supporters. James Thomson’s Seasons, a comprehensive celebration of the metaphysical and aesthetic virtues of the new science, is only the best known of a host of poetic tributes to natural philosophy. Far from dismaying eighteenth-century poets, science stabilized their philosophy, enlarged their vocabulary, and opened unexplored regions for their talents. “Voltaire’s knowledge of physics,” Condorcet asserted, “served his poetic talent”; his “study of the sciences widened the sphere of his poetic ideas, and enriched his verses with new images.”2 And what was true of Voltaire was true of other poets: theological allusions and metaphysical conceits gave way to “philosophic” language, with little loss and much gain to poetry. If poetry in the eighteenth century was indeed in decline, as some of the poets themselves regretfully acknowledged, it was not science that was the cause.
The philosophes seized upon the new science as an irresistible force and enlisted it in their polemics, identifying themselves with sound method, progress, success, the future. They had a certain right to their acquisitiveness. We are inclined to think of the scientists among the philosophes as literary men with a scientific avocation, but, in fact, practically all the philosophes with serious scientific interests—Maupertuis, Buffon, d’Alembert, Lichtenberg, Franklin, Kant, Condorcet—began with science before they turned to philosophy, and the intelligent amateurs and popularizers among them—Voltaire and Diderot among others—did not have far to go to consult the experts; some of their best friends were mathematicians, physicists, and astronomers.
But the philosophes’ seizure of science was a far from untroubled affair. As the sciences grew more technical, more professional, they developed autonomously, and confronted the philosophes, eager as they were to turn knowledge into politics, with linguistic, ethical, and metaphysical difficulties they had not anticipated and for which most of them were ill-prepared. Hume and d’Alembert, Condillac and Kant thought about the philosophical implications of the sciences fruitfully and constructively; they set the terms on which the debate over the nature of science is still conducted today. But there were other philosophes who, as the eighteenth century progressed, found science to be not a servant or an ally but an embarrassment.
THE SCIENTIFIC REVOLUTION was a voyage into abstraction and specialization, but, fortunately for their cause, the philosophes found it possible to dramatize that revolution by deifying one of the revolutionaries. While science was surrendering old mysteries, the men of the Enlightenment constructed a new mystique: they satisfied their need for a representaive figure, their craving for a hero, through Isaac Newton.
Newton was a congenial kind of hero for the philosophes: when Voltaire set the fashion for the Enlightenment by calling Newton the greatest man who ever lived, he contrasted him, significantly, with the heroes that had served earlier, more bellicose ages: “If true greatness consists of having been endowed by heaven with powerful genius, and of using it to enlighten oneself and others, then a man like M. Newton (we scarcely find one like him in ten centuries) is truly the great man, and those politicians and conquerors (whom no century has been without) are generally nothing but celebrated villains.”3
Everything cooperated to make Newton into a fitting object of a mystique. He was eccentric and fallible enough to provide memorable stories—like the imperishable anecdote about Newton meditating on fruit dropping from his trees which Voltaire brought back with him from England. Equipped with penetrating vision where others had seen nothing, unsurpassed and unsurpassable in his achievement, too preoccupied and too aloof to conduct his own polemics, Newton had unified disparate phenomena, laid bare age-old secrets, and, with one almost incredible intellectual effort, compelled nature to order. He had been a visionary disciplined by the appeal to experience, an empiricist illuminated by profound vision, a pioneer who employed all weapons in the scientific arsenal—mathematics, experiment, observation—with equal ease. Such a giant did more than invite assent to his theories; he commanded submission. By mid-century, d’Alembert noted, Newton’s system was “so generally accepted, that people were beginning to dispute their author the honor of having discovered it,” and in 1776 Voltaire surprised no one when he announced, quite simply, “We are all his disciples now.”4 Even the Cartesians were irresistibly drawn into the circle of admiration: Fontenelle composed his eulogy for the Académie des sciences on the occasion of Newton’s death as though he were in the presence of a towering natural force: what a marvelous mathematician, he exclaimed, to have unraveled the mysterious complexities of the universe!5
Not surprisingly, the philosophes’ celebrations of Newton all bear a certain family resemblance: Beccaria was delighted to hear his friends calling him “little Newton”; d’Alembert and Jefferson displayed his portrait in their studies; all of them, following Voltaire, included him in their trinity of the greatest men in history, placing him beside Bacon and Locke or (if they were Germans), Locke and Leibniz. Hume gave Newton a glowing paragraph in his History of England, portraying him simply as thinking man incarnate: “In Newton this island may boast of having produced the greatest and rarest genius that ever rose for the ornament and instruction of the species. Cautious in admitting no principle but such as were founded on experiment; but resolute to adopt every such principle, however new or unusual: From modesty, ignorant of his superiority above the rest of mankind; and thence, less careful to accommodate his reasonings to common apprehensions: More anxious to merit than acquire fame: He was, from these causes, long unknown to the world; but his reputation at last broke out with a lustre, which scarcely any writer, during his own lifetime, had ever before attained. While Newton seemed to draw off the veil from some of the mysteries of nature, he shewed at the same time the imperfections of the mechanical philosophy; and thereby restored her ultimate secrets to that obscurity in which they ever did and ever will remain.”6 It was this magnificent specimen of enlightened man—the philosophe idealized, purified, as he aspired to be—that Kant celebrated and sought to serve in his major philosophical writings. And when Kant suggested that Rousseau deserved to be called the Newton of the moral world, he was at once assigning Newton a place in the intellectual atmosphere of the Enlightenment and giving Rousseau the highest praise he could imagine.
In the deification of Newton, the Enlightenment of the philosophes and the age of the Enlightenment were at one. Devout literary men and philosophers who would have little to do with the philosophes’ radical notions shared, and in fact anticipated, the philosophes’ worship of Newton. At the time of Newton’s death, James Thomson composed a Poem Sacred to the Memory of Sir Isaac Newton, whose hyperbole appeared to its contemporaries as a sober, truthful report—and not to its contemporaries alone. When Thomson had occasion to rethink his verses on Newton and revise his eulogy, he took nothing back, and a quarter of a century later Lessing would note that by itself Thomson’s Zum Andenken des Isaac Newtons, even if he had written nothing else, would have secured him “an outstanding place among poets.”7 Pope’s famous couplet about Newton, which saw him as a divinely inspired bringer of light, became a master metaphor, almost a master cliché, and the adjectives “divine” and “immortal” became practically compulsory. Sometime around 1730, Voltaire put his own version into his notebook: “Before Kepler, all men were blind, Kepler had one eye, and Newton had two eyes.”8 As late as 1750, the publicist Benjamin Martin composed a Panegyrick on the Newtonian Philosophy, in which he described “Natural Philosophy” as a “Mystery that has been hid from Ages, and from Generations; but is now made manifest, to all Nations, by the divine Writings of the immortal Sir Isaac Newton.”9
Interestingly enough, the originator of this literary convention was not a poet but a scientist: when the astronomer Edmond Halley saw Newton’s Principia through the press, he took the opportunity to express his admiration with some prefatory Latin hexameters, and concluded: nec fas est proprius Mortali attingere Divos—it is not lawful for mortals to approach divinity nearer than this. The English scientific community, in fact, despite the professional disputes that disturbed Newton’s later career, and the English crown, despite its intellectual mediocrity, elevated Newton into a major national asset. In 1703, the Royal Society, for years in the hands of aristocratic amateurs, made Newton its president, and in 1705, Queen Anne knighted him—the first time in English history, it seems, that a scientist had been thus honored for his scientific work. When Newton died, he was buried in splendid pomp at Westminster Abbey among the great men of the nation, “like a king,” said Voltaire, who was there, “who had been good to his subjects.”10
With Voltaire as its chief propagator, the mystique of Newton traveled from England to the Continent with little delay. In the 1730s, at the height of his preoccupation with natural science, Voltaire composed some stirring poems in praise of Newton, and in 1738, when the Maupertuis-Clairaut expeditions were producing mathematical proofs of Newton’s claims that the earth is flattened at the poles—a claim that Cartesian astronomers had denied—Voltaire depicted the spirit of Newton exhorting his faithful followers from the empyrean to produce empirical confirmation for his theories. And in the second half of the eighteenth century, nearly half a century after Newton’s death, the abbé Jacques Delille adapted Pope’s famous couplet for his French readers:
O pouvoir d’un grand homme et d’une âme divine!
Ce que Dieu seul a fait, Newton seul l’imagine,
Et chaque astre répète en proclamant leur nom:
Gloire à Dieu qui créa les mondes et Newton!11
In the same manner—that is, with remarkable poverty of invention and equally remarkable dependence on English models—Helvétius, Marmontel, Saint-Lambert offered versified celebrations of Newton the demi-god, the discoverer of universal attraction and the true theory of colors. While in England Newton’s Opticks had aroused the poets’ interest from the moment of publication, in France it was Voltaire, some decades later, who claimed to have been “the first poet to have drawn a comparison from the refraction of light,”12 and once Voltaire had drawn it, others followed.
German men of letters in their turn dutifully copied British and French rhetoric. Albrecht von Haller, groping for an appropriate apostrophe to his fellow student the mathematician and physicist Johannes Gessner, felt compelled to remind him that he was about to follow in Newton’s footsteps and thus enter nature’s secret councils, led by the Newtonian art of measurement, the infallible bridle of the imagination:
Bald steigest du auf Newtons Pfad,
In der Natur geheimen Rath,
Wohin dich deine Mesz-Kunst leitet;
O Mesz-Kunst, Zaum der Phantasie!
Wer dir will folgen, irret nie;
Wer ohne dich will gehn, der gleitet.13
Lessing introduced some variation into the accepted pattern by comparing Newton to Homer and imposing on him the burden of representing the moderns against the ancients: if such a divine man as Newton had chosen to equal Homer in poetry, he would have succeeded. But the variation was insignificant: obedient to prevailing fashion, Lessing punned on the theory of attraction and dragged out the image of Newton, the heavenly visitor:
Die Wahrheit kam zu uns im Glanz herabgeflogen,
Und hat in Newton gern die Menschheit angezogen.14
From country to country and decade to decade, the tributes to Newton changed little. They were always fervent, usually sincere, but in the long run mechanical and monotonous. But then it was precisely this monotony—one poet, usually more well-intentioned than well-informed, rewriting another poet—that gave the literary deification its cultural significance. The poets, after all, claimed neither to solve scientific difficulties nor to provide scientific information; their task was to reflect and diffuse a new attitude toward nature, toward knowledge, toward the world.
The poetic celebration of Newton would have been impossible without the serious exploration of his work that accompanied it, undertaken, first in England and then elsewhere, by mathematicians, physicists, and chemists intent on clarifying the Newtonian system for themselves, for the professional student, and for intelligent but bewildered amateurs like John Locke who wanted to grasp Newton’s system without troubling to learn Newton’s mathematics.
This exploration was essential because Newton, in offering some large answers, had raised some large questions. Newton left some ingenious hints concerning chemistry, but their real meaning and possible fertility remained to be explored; and a number of his most interesting ideas in mechanics were obscurely expressed or incompletely worked out. Newton had expounded, and in his practice triumphantly demonstrated, a method, but its implications for the human sciences, and even the natural sciences, were by no means settled. If audacious propagandists like Voltaire offered relatively simple solutions to Newton’s methodological difficulties, this simplicity was deceptive—a function less of scientific thinking than of polemical skill. In fact, the very direction that science would have to take after Newton remained in doubt. Newton’s own attitude was perspicuous and consistent: he had disclaimed any knowledge of the nature of gravity and humbly deprecated his contributions by reviving the medieval commonplace of “standing on the shoulders of Giants”; late in life he had compared himself to a boy discovering pretty pebbles on the seashore “while the great ocean of truth lay all undiscovered before me.” The philosophes liked to repeat these remarks as valuable support for the Enlightenment’s campaign against system-building and in behalf of “philosophical modesty.”15 Yet, while Newton’s disciples honored Newton’s modesty—did not d’Alembert and Hume and Kant repeat Newton’s injunctions on that score?—some of his more impetuous followers used Newton’s very triumphs as an argument against Newton’s self-restraint and revived the age-old claim for universal knowledge. The history of eighteenth-century science is far more than the history of assimilating Newton’s ideas, confirming Newton’s guesses, generalizing Newton’s conceptions beyond his own expectations, and wrestling with Newton’s philosophical puzzles; especially in the field of mechanics, the Bernoullis, Euler, Lagrange, and d’Alembert did much fruitful work on their own. But “Newtonianism” dominated even those who struck out on new and untried paths so that it incorporated, with its capacious prestige, scientific explorations that had little to do with Newton’s work.
Whatever the difficulties Newton had left, whatever the work of independent researchers, the informal and unorganized troop of Newton’s popularizers did their work quickly and effectively, in England and on the Continent alike. The appetite for expositions and commentaries seemed inexhaustible: Algarotti’s Newtonianismo per le dame was promptly translated into English, as though the English had not yet produced enough popularizations of their own. By mid-century, such books were all over the Western world.
The rapid spread of Newton’s ideas on the Continent only underlines Newton’s towering authority. Many continental scientists knew English, and came to England to visit Newton or his followers; others read the Latin lectures of Newton’s expositors and became Newtonians at a distance. A center—for years, the center—for the assimilation and propagation of Newtonianism on the Continent was the University of Leyden. Boerhaave, the great chemist, botanist, philosopher, and physician who presided over the school of medicine there, was one of Newton’s most faithful and most effective allies. In his published lecture of 1715, the Oratio de comparando certo in physicis, Boerhaave laid down the line that he and his pupils were to follow for decades: Newton’s theory of attraction is the true explanation of celestial and terrestrial phenomena, while Newton’s modest declaration of ignorance concerning its cause and nature is the true method of scientific inquiry; other great natural philosophers, Boerhaave argued, even his compatriot Huyghens, had fallen into erroneous theories through the esprit de système; yet, he added, consistent in this too with Newton’s spirit, this kind of principled caution should not lead to “pyrrhonism in physics”—a proper reliance on experience as point of departure and continuous control, and on reason and mathematics, should lead the inquirer to reliable knowledge of the world of nature.16
Boerhaave reiterated these arguments with the persistence of the pedagogue seized by a persuasive system; his younger colleagues, an impressive group of investigators and publicists, reiterated them in their own lectures and writings, in their own manner. S’Gravesande, who had met Newton and kept in close enough touch with the English scientific fraternity to be elected to the Royal Society, published his treatise Physices Elementa Mathematica, in 1715, “to make good the Newtonian Method, which I have followed in this Work”17; and he continued to make it good in his later writings. Musschenbroek and Nieuwentyt, Boerhaave and s’Gravesande’s younger colleagues, like their elders, corresponded with English scientists, experimented in the hope of confirming Newton’s theories, and publicized their findings and their procedures to a wide audience.
Their influence was nothing less than astonishing. In 1736 Musschenbroek noted with pardonable pride that “Physical science has never been cultivated in Holland so much as it is today,” and that physical science, it was clear, was Newtonian in temper. Physics, he added, “makes new conquests every day, and is insensibly spreading into most professions.” In consequence, the new consumers of science “have formed societies in several of the principal cities, where they occupy themselves with making experiments, using a large number of expensive instruments, and where they spend their time agreeably in research into the properties and operations of all sorts of bodies.”18 This passion for Newtonianism was not confined to the United Provinces; Leyden was a gathering place for foreign students, including Haller and La Mettrie, and foreign visitors, including Voltaire. Books by Dutch scientists were translated as readily as books by English scientists, and carrying the same message they won the same influence. In 1738, upon Boerhaave’s death, Fontenelle acknowledged in his eulogy, “All states of Europe supplied him with disciples, principally Germany and even England, proud though it is—justly—of the flourishing state of its sciences.”19
It was perhaps no coincidence that Fontenelle should have omitted France from his list, for by 1738 the impact of Newton on France was still problematical. But it was beginning to be real enough: in 1732, nearly half a century after Newton’s Principia, Maupertuis, a member of the Royal Society who had for years goaded the Académie des sciences, finally published his Discours sur les différentes figures des astres, the first book by a Frenchman fully to accept and clearly to expound Newton’s theory of gravitation. In 1756, when that theory had triumphed in France, two years before Maupertuis’s death and several years after he had quarreled with him, Voltaire claimed that he had been “the first man in France to explain Newton’s discoveries.”20 In view of the help that Maupertuis had given Voltaire with his chapters on Newton in the Lettres philosophiques, the claim was ungracious in the extreme. Voltaire’s anxiety to participate in Newton’s prestige in France was partly literary vanity, partly an attempt to show himself competent in a difficult and popular pursuit. But it also showed, once again, how strong a hold the mystique of Newton had on its propagators.
Voltaire’s claim was overstated, but it hints at his share in the appropriation of Newton from the enlightened atmosphere of his time for the Enlightenment of the philosophes. It was Voltaire, with his quick intelligence, who was the first of the philosophes to grasp the uses to which Newton’s theories could be put. By no means all of Voltaire’s Newtonianism was manipulative: his excursions to Leyden, his dogged reading of scientific monographs, his conversations with French scientists, his solemn experiments in physics performed at the château and in the company of Madame du Châtelet all display the disinterested side of his passion for scientific understanding. At the same time, first in his Lettres philosophiques, and then, four years later, in 1738, in his Éléments de la philosophie de Newton, Voltaire demonstrated the political utility of a culture hero. Newton was right, and hence the Enlightenment, basing itself on Newton’s method as much as on Newton’s discoveries, must be right as well—it was as simple as that.
In the Lettres philosophiques, Voltaire still held his aggressiveness in check. Here, Voltaire’s Newton is a fascinating and admirable historical personage, the source of anecdotes, the appropriate subject of hero worship. But—as a last concession to the reigning Cartesianism in France and perhaps to his own uncertainty—Voltaire refuses to commit himself wholly to Newton’s theory of gravitation, and takes refuge in a witty comparison: “A Frenchman arriving in London finds things much changed, in philosophy as in all the rest,” he writes in a characteristic passage that has been much quoted. “He has left the world full; he finds it empty. In Paris, one sees the universe composed of vortices of subtle matter; in London, one sees nothing of the sort. In our country, it is the pressure of the moon that causes the tides in the sea; in England, it is the sea that gravitates toward the moon.” Indeed, “with your Cartesians, everything happens through an impulsion which is hardly understood; with Mr. Newton, it happens through an attraction whose cause one does not know any better. In Paris, you think that the earth is shaped like a melon; in London, it is flattened at the two poles. For a Cartesian, light exists in the air; for a Newtonian, it comes from the sun in six and a half minutes. Your chemistry performs all its operations with acids, alcalis, and subtle matter; English chemistry is dominated by attraction.”21 The contradictions between these systems, Voltaire says evasively, are fierce indeed. But whatever the scientific complexities, one thing was perfectly clear to Voltaire, and he did not hesitate for a moment to point it out to his French readers: while Descartes was reviled, intimidated, and hounded from his country, Newton was left in peace, honored, and rewarded. Here was one use of Newton for the Enlightenment: he was a demonstration of the advantages of freedom, and, conversely, of the stupidity of repression.
But even at this early stage, Voltaire’s Newton was not simply a representative figure in the struggle for intellectual freedom; in some pioneering passages of the Lettres philosophiques, Voltaire noted the virtues of Newton’s disciplined empiricism—that famous “philosophical modesty” which was to become such an effective slogan for the philosophes’ assault on Christian theory and on dogmatic metaphysics. Descartes’s physics, Voltaire wrote, was too facile, too dogmatic to be convincing; Newton, in contrast, respected the facts, heroically faced obscure phenomena, and refused to make systems.
From such general approval it was only a short distance to a firm commitment to Newton, and, encouraged by years of research, reflection, and conversations with persuasive Newtonians like Maupertuis, Voltaire made this commitment in his Éléments de la philosophie de Newton. There are no evasions in this book, and few anecdotes. Newton is quite simply the discoverer of the true system of the world, and, quite simply, the destroyer of Cartesian vortices, of subtle matter and the plenum. “This philosopher,” Voltaire wrote in his dedication to Madame du Châtelet, “gathered in during his lifetime all the glory he deserved; he aroused no envy because he could have no rival. The learned world were his disciples, the rest admired him without daring to claim that they understood him.”22
The Éléments is a venture in making Newton understood. “The author of the Éléments,” Voltaire wrote a year after the book appeared, “tried to make these new truths available to minds with little practice in these matters.”23 The book proceeds, in sober, classical logic and with superb lucidity, through three sections, beginning with Newton’s religion, continuing with Newton’s optics, and concluding with Newton’s physics. With a great measure of success, without recourse to mathematics, Voltaire seeks to explain such difficult matters as the nature of perception, the character of colors, the orbits of the planets, the laws of gravitation.
Voltaire’s Éléments, then, is an exercise in high popularization, but it functions in a wider cultural context, as a participant in a great debate. It is not an accident that Voltaire begins his exposition with a series of chapters on Newton’s religious convictions, and calls the whole a book on Newton’s “philosophy.” In the late seventeenth century, and throughout the eighteenth, when the character, the methods, the very territory of the sciences were still unsettled, debates over science were debates over religion, and religion was a subject in which everyone was vitally concerned. Voltaire’s Éléments, therefore, at least touches on issues that agitated educated men—and, as Voltaire’s Madame du Châtelet was not the only one to prove, educated women—in the eighteenth century. The debates between Newtonians and Leibnizians and between Newtonians and Cartesians were debates that Voltaire, alert to controversy, knew to be no mere quarrels over laws of physics. They were, often implicit, sometimes explicit, acknowledgment that the triumph of Newtonian science was transforming the contours of religious belief in the century of the Enlightenment.
THE SCIENTIFIC REVOLUTION of the seventeenth century had marked no break with the Christian view of the world. The discoveries of natural philosophers threatened the grosser forms of superstition, enlarged the bounds of naturalistic explanation, and lent authority to those proofs for the existence of God that relied on the divine work in nature rather than on the divine word to man. It frightened only a few exceptional spirits. “Whatever God himself has been pleased to think worthy of making,” wrote Robert Boyle, as firm in his personal piety as he was bold in his scientific inquiries, “its fellow creature Man should not think unworthy of knowing.” Indeed, “If the omniscient author of nature knew that the study of his works tends to make men disbelieve his Being or Attributes, he would not have given them so many invitations to study and contemplate Nature.”24 Few scientists in the time of Boyle and Newton predicted that true religion and true science would some day be at war; few of them so much as acknowledged that religion and science might belong to two potentially hostile camps. There were border skirmishes, no more, and even these were less between theology and science than between theology and some extreme philosophical consequences drawn from scientific discoveries.
It is true that churchmen condemned certain scientific views as heretical, but this was a familiar story, and seventeenth-century Christians disagreed, as Christians had always disagreed, on the wisdom of particular condemnations. To side with Galileo was not to side with infidelity. Throughout the seventeenth century it was the rare scientist who repudiated Providence or miracles, even obliquely; Galileo’s spirited polemics, which had frightened the papacy, had been directed mainly against Aristotelian metaphysics, crude Biblical literalism, and the claim that theology was the master science; the polemics of later scientists aimed at similar targets.25 Newton thus pursued his researches into Biblical chronology in the best of scientific company. Although they were all revolutionaries, natural philosophers solemnly and sincerely announced their discoveries as demonstrations that Christianity was true and in fact divine; most of them would have been outraged to see the philosophes in the eighteenth century abuse these discoveries to demonstrate that Christianity was in fact all too human and false.
For Newton, God was an active being: he is Creator and watchful master, wise, just, good, and holy. This “Being,” Newton argued, “governs all things, not as the soul of the world, but as Lord over all”; he is a “powerful, ever-living Agent” who prevents the fixed stars from falling upon one another—perhaps by natural, perhaps by miraculous, means—and occasionally corrects the irregularities introduced into the solar system by the eccentric orbits of the planets and the incursions of comets.26 The laws of nature, themselves the creation of God, must be supplemented by special acts of his Providence. Like other modern Christians of his day, Newton was inclined to read the Pentateuch not as a literal report but as a convincing account of creation and man’s earliest history adapted by the narrator to the limited understanding of his audience. Yet Newton did not doubt that while Moses had used metaphors and images, he had told the essential truth: whatever God’s precise mode of procedure, whatever the precise number of days he had taken to make the universe, God, Newton believed, had created the world and every living creature. In an age and in a country sensitive to the threat of infidelity, Newton kept his fellowship at Cambridge and enjoyed profitable preferment in the government service. He was a Unitarian, but not a deist: no deist, no matter how brilliant, could have had Newton’s public career.
Yet, two generations of philosophes, anxious to poison relations between science and religion, found that, whatever Newton’s own religious convictions, they could do without them. “I have not seen a Newtonian,” Voltaire claimed in the 1730s, “who was not a theist in the strictest sense of the word.” All of “Newton’s philosophy necessarily leads to an awareness of a supreme Being, who has created everything, arranged everything freely.”27 But Voltaire was speaking only for the first generation, which eliminated the distinctly Christian element from Newton’s thought. The second generation would go beyond even this and eliminate the religious element altogether.
It is one of the minor ironies in the larger ironic pattern that Voltaire’s insistence on a stable, lawful universe as the only basis for true natural religion placed him in the company of Leibniz, the great compromiser, with whom Voltaire thought he was disagreeing. Beginning in 1705, Leibniz had been embroiled with Newton—or, rather, since Newton refused to be drawn, with Newton’s spokesmen—first over the invention of the calculus, then over the character of gravity, and finally, beginning in 1715, over the theological consequences of Newton’s God. The debate, conducted in Newton’s behalf by Samuel Clarke, a skillful and well-informed controversialist—“a veritable thinking machine,” Voltaire called him28—ranged widely over many theological and metaphysical questions raised by Newton’s system, but for the philosophes the nature of God and the influence of Newton’s beliefs on the status of natural religion remained the critical questions. “Natural religion itself,” so Leibniz began his assault, “seems to decay (in England) very much,” and much of this seemed to him the fault of Locke’s and Newton’s doctrines: “Sir Isaac Newton, and his followers,” Leibniz argued, have a “very odd opinion concerning the work of God. According to their doctrine, God Almighty wants to wind up his watch from time to time: otherwise it would cease to move. He had not, it seems, sufficient foresight to make it a perpetual motion.” In Leibniz’s sarcastic caricature, Newton’s God is a clumsy watchmaker, “obliged to clean” his creation “now and then by an extraordinary concourse, and even to mend it.” On the contrary, Leibniz insisted, “the same force and vigour remains always in the world, and only passes from one part of matter to another, agreeably to the laws of nature, and the beautiful preestablished order.” God’s miracles are acts not of repair, but of grace. “Whoever thinks otherwise, must needs have a very mean notion of the wisdom and power of God.”29
Much to Leibniz’s annoyance, Clarke in his reply turned the charge of subverting natural religion against the aggressor: “The notion of the world’s being a great machine, going on without the interposition of God, as a clock continues to go without the assistance of a clockmaker; is the notion of materialism and fate, and tends, (under pretence of making God a supra-mundane intelligence,) to exclude providence and God’s government in reality out of the world.”30 Stung, Leibniz sent a rejoinder, and the correspondence moved through many fields of controversy: Leibniz charged that Newton had reintroduced the old, discredited notion of the scholastic, occult qualities, with his mysterious doctrine of gravitation; that Newton had converted the physical career of the world into a perpetual miracle; and that Newton (and with him Clarke) had failed to understand the principle of sufficient reason, which would have taught them that God “wills only to produce what is the best among things possible”31—a principle to which Voltaire would return as late as the mid-1750s, in his Candide.
The correspondence was published in 1717, translated into German and French in 1720, and widely read; when Voltaire used it in the first book of his Éléments, its arguments on the nature of space and time, the vacuum, and the role of God in the physical universe, were familiar. “It is perhaps,” Voltaire noted, “the finest monument we have of literary combat.”32 Voltaire found himself in a strange situation. He sided with Clarke and Newton against Leibniz, without hesitation: God had the freedom to make the world he chose to make, and in any event, Newton’s ideas, far from destroying natural religion, guaranteed it. But without conceding, perhaps without seeing it, Voltaire found himself constrained to accept Leibniz’s central contention: the universe is regular and needs no miracles.
The awkwardness of Voltaire’s argumentation suggests that the protagonists in the great literary combat were in a false position. They were partly vindicated, partly contradicted by the course of natural philosophy in the eighteenth century. Leibniz was proved right in defending the regularity of the universe, wrong to think that his view would preserve natural religion; Clarke was wrong to insist on divine intervention, proved right in seeing the Leibnizian view as an invitation to materialism. And Voltaire, for his part, was right to insist on regularity, on Newtonian grounds, wrong to think he could stem the tide of atheism, even though for several decades it was Voltaire’s particular brand of Newtonian deism that dominated the Enlightenment.
Doubtless Voltaire contributed to this complex development by pitting science against Christianity, though not against religion. Whatever scientists themselves might believe, as Newtonian physics secured its hold in the age of the Enlightenment, the philosophes found much cause for satisfaction: for them at least, the developments in science offered confirmation for their secular philosophy. The scientific community itself long kept a religious cast; while there were some tensions between science and religion in the eighteenth century, the conflict did not reach the stage of war to the death until a hundred years later, with Darwin. The worshipful study of God’s work, which had inspired Christians for many centuries, retained its vitality for many, perhaps most, scientists throughout the age of the Enlightenment. Stephen Hales, the distinguished English chemist and physiologist, was an Anglican divine; Leonhard Euler, perhaps the greatest mathematician of the eighteenth century, always remained a devout Calvinist; Joseph Priestley, a versatile and inventive scientist and philosophical materialist, combined his radical notions with Unitarian Christianity and a firm confidence that the Second Coming was at hand; Albrecht von Haller was tormented by his bouts of unbelief, but never ceased to defend Christianity against Voltaire and other impious philosophers.
Yet, however much devout scientists might object, it became obvious that God had constructed the world with fewer irregularities than God’s sublime interpreter, Newton, had imagined; as d’Alembert put it, theological explanations of mechanical laws turned out to be not merely false but irrelevant. But most philosophes argued that they were, above all, false, and the scientists offered them good evidence in behalf of their arguments. The astronomical irregularities which, Newton had insisted, required divine intervention in the running of the universe, proved to be part of larger, hitherto incomprehensible regularities. By the 1770s and 1780s, brilliant mathematicians like Lagrange and Laplace had offered naturalistic explanations for planetary perturbations and had established the essential stability of the solar system. It was scientists like these who moved Kant to praise the sound quality of natural philosophy in his time. In 1692 Newton had told Richard Bentley that he had labored to establish “such principles as might work with considering men for the belief of a Deity”33; a hundred years later, while there were many scientists who were Christians, their discoveries no longer worked for the same purpose. The work of scientists and the ideology of philosophes were by no means the same thing, but at the very least the direction of science could give deists and atheists great comfort and supply them with what they wanted—Newton’s physics without Newton’s God.
In this development, Descartes played an even stranger role than Leibniz. As the professed followers of Newton, constructing their secular philosophy of science—and their secular philosophy through science—the philosophes ostentatiously joined the camp of the anti-Cartesians, for since the late seventeenth century the main burden of scientific controversy had fallen on Cartesians and Newtonians. It is true that the ideas, and perhaps even more, the literary and intellectual style of Descartes, retained their power over some of the philosophes—especially in France, where Montesquieu and Diderot and the others acquired their Descartes, as they acquired their classics, at a most impressionable age, in school; but these philosophes were ungenerous in acknowledging and hasty to minimize that power. Descartes ranks among the teachers of the Enlightenment and among its victims.
The Enlightenment’s victimization of Descartes was never wholly unambiguous: his thought was too rich, he was too useful either as a cardboard hero or, far more often, cardboard villain, to permit the philosophes to agree on his real stature; he was, as d’Alembert rightly observed, an “extraordinary man” whose reputation had “varied greatly in less than a century.”34 Even his seventeenth-century readers who were, after all, close to him in time, had argued over him as they had never argued over Spinoza or Newton.
Descartes’s first admirers had accepted him at his own valuation—as the lonely, self-impelled hero of the Discours de la méthode, the bold, persistent skeptic who liberates himself from the dead hand of traditional philosophy and rigid theology to stand forth as a model to his fellow men. Later, long after he was dead, historians anxious to simplify a complicated situation arranged a duel between Bacon the empiricist and Descartes the rationalist, but to their contemporaries the two were firm allies, prophets of a new scientific age that would improve the lot of man.35 Indeed, in the middle of the seventeenth century, Descartes’s most prominent followers were in England rather than in France. The theologians at Cambridge read Descartes with profound admiration; Henry More, opening his correspondence with the master in 1648, rather grandiloquently hailed Descartes as a giant who made all other philosophers, even great philosophers, appear as mere pygmies. More and his fellows were never uncritical Cartesians—they were, in their own highly individual Anglican way, Platonists—but for a time they were intensely stimulated by Descartes’s ideas, and felt safe with them: “There is no philosophy, indeed, except perhaps the Platonic,” Henry More asserted, “which so firmly shuts the door against Atheism.”36 Some years later, More and Cudworth regretted their infatuation and denounced the philosophy of Descartes as an invitation to godless materialism. But that was later, in the 1660s; Descartes died in 1650, well before his Cambridge supporters became his antagonists. His fame in France, on the other hand, was almost wholly posthumous; it had to await the assimilation of his philosophy to Catholic orthodoxy, for from the beginning there had been critics like Pascal who feared Descartes as a glib tempter who would seduce men away from belief in the active Christian God. But Descartes became fashionable in high society and valuable to highly placed apologists; gradually, in the hands of philosophers like Malebranche and Fénelon and biographers like Baillet, there emerged a pious, safe, modern but wholly reliable Descartes, young Henry More’s Descartes—not an invitation to, but a bulwark against, atheism.
With the appearance of Newton’s Principia other aspects of Descartes’s thought, his physics and his scientific method, became embroiled in controversy, and this later at once simplified and complicated the philosophes’ polemical task. It simplified it by permitting them to construct a Descartes who was the ideal type of the rash metaphysician; complicated it by compelling them to make a complex judgment of him. Descartes the physicist, it seemed, was not the same man as Descartes the critical philosopher, and the performance of that philosopher, in turn, varied radically in quality from task to task.
Newton himself contributed to the caricature of Descartes by treating him as his supreme, almost sole opponent. Hence Newton could not—or at any rate did not—acknowledge, even to himself, the great debt he owed to Descartes: “Error, error, non est Geom” he scribbled over and over again in the margins of his copy of Descartes’s Geometry, while in public, in the Principia, he scolded Descartes for his mistakes and passed over his contributions to the new science in silence.
This pettiness, though deplorable, was perhaps inescapable; controversy is not an atmosphere calculated to produce disinterested judgments on the merits of one’s antagonist. Besides, the construction of a simplified Descartes enlarged the public for the new science by encouraging the kind of vivid teaching that would make Newtonianism memorable: in 1697 Samuel Clarke cleverly offered the English public a new Latin translation of Jacques Rohault’s immensely influential Cartesian textbook, Traité de physique, first published in 1671, and haunted the text with Newtonian annotations and footnotes which, to the amusement and instruction of its many readers, made the original text appear ridiculous.37
Doubtless, much of that text was, if not ridiculous, wholly untenable. Descartes’s logical arguments proving that the universe was a plenum and that the planets were dragged around the sun in vortices could not stand the rigorous scientific examination they received at the hands of Newton and his followers. And all the philosophes knew enough about physics and astronomy to ridicule Descartes’s hostility to the void and ignorance of gravitation. Yet clearly what really mattered to them was less the content of Descartes’s astronomical notions than the method that had led him to arrive at them. The question of Descartes in the Enlightenment, therefore, resolved itself into two related questions: what was the impact of his skeptical philosophy on theology? and what was the nature of his scientific method? The Enlightenment, which was seeking at once for arguments against Christianity and a basis for reliable knowledge must therefore give Descartes a mixed reception; Diderot, who knew his Descartes well, spoke for his French brethren when he characterized him epigrammatically as an “extraordinary genius born to mislead and to lead.”38
While the philosophes continued to debate details of Descartes’s meaning, their image of him became as conventional as the poets’ image of Newton. Voltaire, who furnished literary models for so many of the Enlightenment’s ideas, offered a series of convenient metaphors for the little flock. “Descartes,” Voltaire wrote, “gave sight to blind men; they saw the errors of the ancients and his own”; his radical skepticism, in other words, had helped to destroy the pernicious metaphysics of the Scholastics and offered a method capable of destroying the rather less pernicious metaphysics of seventeenth-century philosophers, including his own. “The path he opened has, since his time, become immense”; we owe him what we owe to all pioneers respect for being first. It may be true, Voltaire thought, that Descartes “deceived himself, but at least he did it with method and in a consistent spirit; he destroyed the absurd chimeras with which young minds had been filled for two thousand years; he taught the men of his time to reason, and to employ his own arms against him.” And so, “it is not too much to say that he was estimable even in his mistakes.”39
Other French philosophes accepted this estimate without question. However admirable Descartes had been in his assault on medieval nonsense, his method remained a fertile source of new nonsense; Newton had never suffered from Descartes’s esprit de géometrie et d’invention. In his brilliant Traité des systèmes, Condillac included Descartes among the four great system-makers of the seventeenth century, and criticized him both for his deductive method—“which has bred nothing but errors”—and for his boast that he could construct the world with matter and movement. Newton had been content with observing the world, “a project less beautiful than Descartes’s, or, rather, less daring, but wiser.”40 D’Alembert agreed. In his Discours préliminaire to the Encyclopédie, he generously sketched Descartes’s troubled career and courageous philosophy: Descartes, he said, was brave, a victim of persecution, an inventive philosophical mind who brilliantly applied his method with impressive results to a variety of sciences; if he was wrong, as he was especially in astronomy, he remains a leader in the liberation of the human mind. He showed men the way “to throw off the Scholastic yoke, of opinion, of authority,” and by leading the revolt himself, “performed greater services to philosophy than, perhaps, any of his successors.” He may, indeed, be thought of “as the leader of a conspiracy with the courage to rise up against despotic and arbitrary power,” and to put down the foundations of a “juster and happier government which he himself did not live to see.”41
Grudging as they were, then, the philosophes recognized Descartes as a John the Baptist in the long struggle against superstition, an admirable but tragic pioneer. The materialists among the philosophes—La Mettrie, Holbach, and Diderot in his later years—went beyond this. They were especially indebted to Descartes’s geometric conception of God and materialistic interpretation of animal existence; by delineating a God who withdraw once he had built his machine, and creatures that were mere soulless automatons, Descartes permitted his radical successors to construct a wholly materialist world view. Like the disillusioned Cambridge Platonists before them, the deists among the philosophes accused Descartes of preparing the way for atheism—“I have known many persons,” wrote Voltaire, “whom Cartesianism has led to admit no God other than the immensity of things”42—an accusation that the materialists among the philosophes converted into praise. Descartes’s role in the Enlightenment varied, but this much is clear: the philosophes exploited him, as they exploited Newton, in the service of secularism. The antireligious implications of the scientific revolution obviously did not trouble them. Science did become a problem for the Enlightenment, but the problem lay elsewhere.
LATE IN 1753, in his aphoristic Pensées sur l’interprétation de la nature, Diderot made a striking, if slightly hedging, prediction. “In less than a hundred years,” he wrote, “there will not be three great mathematicians left in Europe.” Mathematics will come to a standstill “at a point where the Bernoullis, where Euler, Maupertuis, Clairaut, Fontaine, d’Alembert, and Lagrange have left it. They will have erected the columns of Hercules. We shall not get beyond them.”43 Time proved Diderot’s prediction to be worthless; even in his own time mathematicians continued to do significant work. But it suggested, though only by implication, the emergence of some new interests. By mid-century, natural scientists were discovering some relatively unexplored fields. With Newton’s physics, astronomy, and optics entrenched everywhere, even in France, ambitious young men found room for their energies in the study of the earth, of life, of substances—often in the name of Newton.
Newton’s prestige was untouched. If effusions about him grew rarer it was simply because poets had said as much about him as could be said about any man. Newton’s name remained as magical and his ideas as commanding as ever, and the sciences peculiarly associated with him continued to advance on a broad front of agreement. The newer sciences, on the other hand—geology, biology, chemistry—continued to generate new puzzles; they compensated for their lack of authority with sheer excitement. John T. Needham, a priest whom Voltaire derisively dismissed as an “Irish Jesuit,” even though he was neither Irish nor a Jesuit, “proved” the existence of spontaneous generation, but the Italian priest Lazzaro Spallanzani repeated and refined Needham’s experiments and discredited Needham’s discoveries. Two schools of biologists—one, the preformationists, arguing that the embryo is wholly formed at conception, the other, that the embryo begins with mere undifferentiated potentialities which are realized in the course of development—confronted one another with incomplete and inconclusive evidence. In 1744 Abraham Trembley achieved instantaneous though rather short-lived celebrity when he published his observations on the fresh water polyp, which could regenerate itself into new complete polyps when cut to pieces by the experimenter. His work opened heady if rather dim vistas into nature’s powers to repair itself without outside aid, and it gave intellectual support to materialists. Subjects such as the classification of plants, the age of the earth, the relations of animal species to one another engaged the earnest attention of natural philosophers—the philosophes among them.
The ambition of these biologists was clear: to become the Newton of living nature. Maupertuis, as gifted a naturalist as he was physicist, whose contributions to biology have been overlooked in the dazzling light of Voltaire’s malicious and comical attacks upon him, aroused widespread debate with his brilliant, prescient hypotheses on the nature of heredity and the character of species. As Newton’s name was often in Maupertuis’s writings, Newton’s theories and methods were always in his mind: he thought it possible that Newton’s theory of gravity might have its counterpart in biology, and his investigations into genetics were models of the kind of scientific care that eighteenth-century scientists, not unjustly, connected with the name of Newton.
Among the aspirants to Newton’s mantle there was one, Buffon, who was widely thought to deserve it; in 1751, when only a few volumes of his vast Histoire naturelle had appeared, d’Alembert hailed him as a sage who rivaled Plato and Lucretius.44 Buffon was not inclined to dispute d’Alembert’s estimate; though a genial man, he was vastly ambitious and did not scruple to exploit his post as keeper of the Jardin du roi, or a stable of associates willing to work under his direction, to improve his opportunities for glory. But Buffon’s career was a career in the service of science as much as of himself. His magnificent, expansive Histoire naturelle was an epic effort to write the biography of the world, the work of a man who was at once a skillful mathematician and meticulous stylist, Newtonian in thought and Cartesian in clarity, comprehensive methodologist and diligent empiricist, bold polemicist in behalf of autonomous science and tactful courtier anxious to escape trouble with the authorities. His work had something for everyone interested in nature, which, in eighteenth-century France, meant practically every literate adult. He encompassed the history of the earth from the moment it had first been shaken loose from the sun by a comet, blazing hot, to a time of universal death on a frozen planet; he wrote about the formation of the continents, the nature of man, about animals, plants, rocks. The profusion of his work mirrored the lavish wealth of nature.
The pages of Buffon’s vast and varied production testify to his deep, passionate attachment to nature; he had an almost religious enthusiasm for it, controlled only by his respect for method and care for literary style. “Natural History,” he wrote in 1749, “taken in its full extent, is an immense History, embracing all the objects that the Universe presents to us. This prodigious multitude of Quadrupeds, Birds, Fish, Insects, Plants, Minerals, etc., offers a vast spectacle to the curiosity of the human spirit; its totality is so great that it seems, and actually is, inexhaustible in all its details.” It seems, Buffon goes on, “that everything that can be, is; the hand of the Creator seems not to have opened to give being to a certain fixed number of species; rather, it seems that it has thrown out, all at once, a world of beings related and unrelated, an infinity of harmonious and unharmonious combinations, and a perpetual destruction and renewal.”45 Nature is not a thing, or a single being; it should be regarded as “a living power, immense, which embraces everything, animates everything,” created, and given its marching orders, by “divine Power.” Nature is “a work perpetually alive, a worker ceaselessly active, who knows how to employ everything.” It is inexhaustible: “Time, space, and matter are its means, the Universe its object, movement and life its goal.”46
Faced with such immensity, such variety, such inexhaustible energy, the natural scientist, Buffon argued, must combine two apparently incompatible qualities, the “large vistas of an ardent genius who encompasses everything with a single glance, and the small attentions of a laborious instinct which attaches itself to a single point.”47 Like Falconet in the arts, Buffon had nothing but contempt for amateurs who lack both vision and patience, and pleaded for the professional scientist who disciplines his speculations with his firm grasp on scientific method and animates his knowledge with the kind of imaginative insight that only the thoroughgoing grasp of facts can produce. “Sensible people will always recognize that the only and true science is the knowledge of facts.”48 Himself a noted stylist and student of style, Buffon thought clarity one of the distinct contributions of the eighteenth century: after the immense, unreadable compilations of earlier ages, he wrote, their stylistic faults “have been corrected in our century; the order and precision with which we write today have made the Sciences more agreeable, easier,” and, he added, “I am convinced that this difference of style contributes perhaps as much to their advancement as the spirit of research that reigns today.”49 Buffon’s love of nature was lyrical, but he did not permit his passion to muddy his thinking.
This commitment to clarity was of great importance in a time of dizzying advances in the natural sciences. As Buffon saw—and, as the vagaries of romantic scientists after his death would demonstrate, saw rightly—the gravest menace to correct scientific understanding was the failure to separate objective inquiry from subjective wishes, the insistence on importing ethical or aesthetic considerations into scientific inquiry. With a generosity rare in his time, Buffon praised the ancient Greeks for being the first naturalists; in offering “faithful histories” of natural objects, he noted, the ancients were perhaps superior to the moderns. But the ancients had failed to perform the second half of scientific inquiry, “the exact description of everything,” because they had insisted on the utility of philosophizing and despised “vain curiosity.”50 Hence they had neglected botany and physics alike. The implication was clear: only inquiry directed exclusively to the pursuit of truth could be adequate to the questions scientists sought to answer.
But truth, as Buffon also recognized, was a complex word, used in confusing ways. Much like Hume, though for different purposes, Buffon divided objects of knowledge into two parts—mathematical truths, which depend on definitions and are therefore abstract, intellectual, arbitrary; and “physical truths,” which are, in contrast, not arbitrary at all; “they do not depend on us and, instead of being based on suppositions we have made, they rest only on facts.”51 To say this was not to despise logic and mathematics, but to define their proper function and warn against their abuse. “The most delicate and most important point in the study of the Sciences is here: to know how to distinguish clearly what is real in a subject from what we put into it arbitrarily, to recognize clearly the properties that belong to it and those we lend to it, seems to me the foundation of the true method for guiding one’s conduct in the Sciences.”52
These methodological cautions in no way impeded Buffon’s expansive will to theory. He developed theories of the earth and the heavens, speculated on the organization of the human animal—for man, as he said, must be recognized to be an animal—participated prominently in eighteenth-century debates on perception, generation, and species. His energy was remarkable even in an age rich in energetic men; his encyclopedia of animate and inanimate nature was comprehensive.
It was also subversive of established Christian belief. Buffon himself might have demurred at being called a philosophe: his relations with Voltaire, d’Alembert, and Diderot, though generally amiable, were rather reserved. But the Encyclopedists had no hesitation in claiming him for the good cause, and foreign visitors like Horace Walpole and David Hume included him among the philosophes without hesitation and with perfect justification.53 Buffon, for his part, made obeisances to established authority—he wanted, above all, to get his work done. When the Faculty of Theology at the Sorbonne complained, in 1751, that his geological writings permitted impious inferences and threw doubts on Scriptural statements, Buffon promptly retracted and proclaimed his complete faith in the Bible: “I declare,” he wrote piously, “that I had no intention whatever of contradicting the text of Scriptures; that I believe, with complete firmness, everything that it says about Creation, whether it concerns the order of time or the circumstances of the facts; and that I give up everything in my book, dealing with the formation of the earth, and in general everything else, that could be contrary to Moses’ narration—I had presented my hypothesis concerning the formation of the planets, after all, as a pure philosophical supposition.”54 No retraction could be more complete or less sincere: Buffon continued his investigations into the formation of the earth with complete disregard of the dates to which the devout felt compelled to subscribe. He was a radical in what he wrote, in what he merely implied, in the general direction of his work. He was an Anglomaniac for the reasons Voltaire was an Anglomaniac, an admirer of Locke, an advocate of experimentation and a critic of metaphysics, all for the philosophes’ reasons and with the philosophes’ rhetoric. Indeed, the figures on the age of the world that he permitted himself to publish, suspicious as they were to orthodox Christians, were bland compared to his private guesses, which would have scandalized them completely: “When I counted only 74,000 or 75,000 years for the time passed since the formation of the planets,” he noted in one of his manuscripts, “I gave notice that I constrained myself in order to oppose received ideas as little as possible.”55 He was convinced that to account for the palpable facts of geology, the earth must be assigned an age not of thousands, but of millions of years. In the same way, his geological speculations offered alternatives to the Christian creation myth, his biological speculations alternatives to the Christian view of man. Beyond all this, the bulky authority of his work confirmed his philosophical tendency to the most casual reader: his history of nature concentrates with ostentatious singlemindedness on the creation rather than on the creator. Whatever his private religious views, Buffon’s temper was the temper of the Enlightenment: his explanation of astronomical, geological, archaeological, and biological phenomena was wholly naturalistic, his style of thinking wholly secular.
In the light of Buffon’s magisterial effort and Maupertuis’s pioneering investigations, both widely known by 1753, Diderot’s refusal to grant mathematics a future acquires a certain plausibility. But, plausible or not, its deepest meaning does not lie here; like many predictions, Diderot’s prediction concealed a wish. Diderot was anxiously seeking to keep alive a dying ideal, and his anxiety suggests that with all their noisy affection for science, far from taking their ease in the world that Newton’s researches had disclosed, some of the philosophes at least were greatly troubled by it. The pursuit of a scientific world view evidently imposed a strain on some of its most articulate devotees. Diderot, after all, had the competence of the well-informed amateur in mathematics; his suspicion of it was something other than the resentment of the ignorant against an intellectual instrument he could never master.
One aspect of Diderot’s uneasiness lies on the surface; it was the resistance of the versatile man of letters to the professionalization of science. Mathematics symbolized the threat that the radical philosophes, with their scientific propaganda, had raised to themselves; the triumph of their cause threatened the extinction of their type.
The philosophes should not have been surprised to see that scientific progress exacted its price. But surprised or not, some of them did not like to pay it. Scientists were coming to rely increasingly on the language of mathematics—exact and objective but abstract—and to discover the advantages of the division of labor, which made intelligent participation in the scientific process increasingly difficult. In the seventeenth century scientists had been “natural philosophers”: Boyle had been chemist, physicist, theologian, man of letters all at once, and a member of an international community in which amateurs mixed freely with professionals. His versatility was characteristic of his fellows. In the eighteenth century, “natural philosophers” became scientists, general scientists became specialists. “Physics” was first used in its modern sense, excluding chemistry and biology, in 1715, and while the new usage established itself slowly—at mid-century d’Alembert could still say that the phenomena of chemistry as well as electricity were in the domain of the physicien56—its eventual triumph was inescapable. It was in this period also that astronomy was first explicitly separated from astrology, that Hartley first used the word psychology as we use it today, and that chemistry and chimie acquired their restricted, current meaning; this growing precision in terminology mirrored the growing specialization of the scientist.
In this new professional atmosphere, the gentleman-scientist survived—I have said that the passion for science spread more widely than ever—but he withdrew into the private sphere or, if he competed with professionals, cut a pathetic figure. As late as 1764 the Anglican cleric Richard Watson could still be appointed professor of chemistry at Cambridge even though, as he later conceded, he “knew nothing at all of chemistry, had never read a syllable on the subject, nor seen a single experiment in it.”57 But such an unprofessional career was becoming an anachronism, even in the English universities. The age of universal knowledge was over; and the philosophes, for all their scientific bent, could not help but lament its passing. “It’s not,” Voltaire wrote, “that I’m angry to see philosophy cultivated, but I don’t want it to become a tyrant who excludes all the rest.”58 It was an understandable but no longer very tenable position, as Voltaire himself felt compelled to admit in private. “Literature,” he noted rather sadly, “has become immense, the number of books innumerable, universal knowledge—science—impossible.”59 Around the time that Voltaire confided this disappointment to his notebook, Wieland complained that the sciences had split up into “a thousand sects,”60 and Diderot, in helpless longing for the old comprehensible scientific style, denounced the austere mathematical language of Newton’s Principia mathematica as “the affectation of the great masters,” as “the veil” which scientists “are pleased to draw between the people and nature.”61 And he wistfully reiterated the old ideal of the universal cultivated man: “Happy the geometer in whom a consummate study of the abstract sciences has not weakened the taste for the fine arts; to whom Horace and Tacitus will be as familiar as Newton; who could discover the properties of a curve and sense the beauties of a poem.”62 Diderot, like Voltaire and Wieland, understood that the realization of a new and, to the philosophes, desirable ideal—the man who understands and by understanding, masters nature—was driving out the old and equally desirable ideal: Renaissance man.
This was bad enough, but Diderot’s malaise went deeper than this. Precisely at the moment when the time for amity seemed to have come, the new philosophy threatened to render man’s relation to nature problematical once again. Eighteenth-century thought had liberated man from his filial dependence on God and made him part of nature, but the philosophical anthropology of the philosophes, which promoted man from servitude, ironically enough demoted him at the same time—from his position little lower than the angels to a position among the intelligent animals. While man seemed on the point of conquering his worldly domain through his critical intelligence, he was faced with a second expulsion from his terrestrial paradise, and this time the avenging angel was man himself.
The threat, as I have said, was not chiefly to man’s aesthetic enjoyment of the world about him: far from being anxious over Newton’s universe, the poets thrived upon it. “Although I’m in commerce with Newton-Maupertuis and Descartes-Mairan,” Voltaire wrote to his old teacher, the abbé d’Olivet, “this does not prevent Quintilian-d’Olivet from being always in my heart.” He could not see, Voltaire insisted, “why the study of science—la physique—should crush the flowers of poetry. Is the truth such a poor thing that she cannot stand the ornamental?” Sound thinking and eloquent speech, deep feelings and good expression, are not enemies to science: “No, certainly not; to think that would be to think like a barbarian.” After all, Voltaire pointedly reminded his Jesuit teacher, “Multae sunt mansiones in domo patris mei,” and a person like Madame du Châtelet, who understands “Newton, Vergil and Tasso,” far from being a freak or a survival, was characteristic of her time.63
The apologetic tone in Voltaire’s assertions is faint, but audible—here is, after all, a pupil addressing a former preceptor, a deist, a priest, an embattled literary man another embattled literary man; and Voltaire’s denial that science and poetry are at war, like the denials by pious scientists late in the seventeenth century that science and religion were at war, only suggests that the war was real enough. But Voltaire, and his mistress, even if they saw a problem, also embodied the solution: in their work, in their whole mode of life, they bridged the threatened separation of science and art, science and culture, in a personal union. The threat of science to life lay elsewhere: it lay in its neutrality, its chilling objectivity.
The irresistible propulsion of modern scientific inquiry was toward positivism, toward the elimination of metaphysics, and the clean separation of facts and values, foreshadowed by Bacon, implied by Newton, triumphantly announced by Hume, taken for granted by the leading scientists of the late eighteenth century. Scientific thinking exacted the stripping away of theological, metaphysical, aesthetic, and ethical admixtures that had been a constituent part of science since the Greeks; scientific philosophers of the eighteenth century, with justice, treated these admixtures as impurities, as survivals from earlier stages of consciousness. Every scientific discovery weakened the hold of theological explanation, metaphysical entities, and aesthetic considerations: the orbits of planets were neither beautiful nor ugly; the law of gravitation was neither cruel nor kind; observed irregularities in the skies proved nothing about divine activity. And every improvement in scientific terminology or mathematical formulation further liberated scientists from old anthropomorphic conceptions of the world and reduced to irrelevance many of the old questions that philosophers had addressed to nature.
It was an exhilarating development. After a millennium of the reign of fancy, the reign of fact was at hand; but, as the philosophes’ treatment of nature shows, it was a confusing and at times frightening development as well. Nature had always been a word rich in comforting associations, a profuse, almost inexhaustible metaphor, and the philosophes were reluctant to surrender all these comforts without a struggle. In the age of the Enlightenment, therefore, nature continued to supply norms for beauty and standards for conduct—at least to some philosophes; and the philosophes continued to treat nature rhetorically as a bountiful mother, a treasure house lying open to be raided, a servant waiting for orders, a treacherous opponent requiring constant vigilance. The deists admired nature as a storehouse of lessons and evidence of divine skill; the materialists celebrated it as the origin of all things which, therefore, made the constructions of theology wholly unnecessary. Optimists and pessimists among the philosophes debated just how ready nature was to be dominated, how shrewd or vicious in its resistance, but they agreed that whether man’s relation to nature must be viewed as a collaboration or as a duel, that relation was intimate, inescapable, and exclusive. And some philosophes, Diderot being prominent among them, saw nature as a refuge from science.
The result was a curious set of contradictory attitudes toward science that troubled the philosophes’ clarity of thought and mitigated their pleasure in the process of scientific investigation. Having made man master in his own house, some of the philosophes felt like strangers in it, and they could not quite suppress their longing for ancient simplicities. This nostalgia was by no means universal among them; on the whole one can say that the philosophes who knew science best feared it least. Hume, d’Alembert, and Kant are the fathers of three divergent modern philosophies of science—the first of empiricism, the second of positivism, the third of critical idealism—but their general attitude toward science was one of warm welcome. Each in his own way sought to work out the epistemological and metaphysical meaning of science, and sought to establish reliable standards for ethical and aesthetic judgments outside the confusing tangle of meanings clustering around the word “nature,” but each did his work in the name, and without fear, of Newton. Similarly, Voltaire showed in his celebrated popularizations how thoroughly he had entered Newton’s world and how fearlessly he was ready to draw its philosophical implications. At the same time, Voltaire’s scientific philosophy harbored a rather surprising survival from the prescientific view of nature—final causes. Voltaire had ridiculed as naïve the claim that “rocks were created to build houses” and “silkworms born in China that we might have satin in Europe.” But unlike Buffon, who firmly rejected final causes as a metaphysical abstraction, Voltaire insisted that when the effects were invariable, nature’s purposes could be discerned through the idea of final cause: we should be “mad to deny that stomachs were made to digest, eyes to see, ears to hear”—a refinement on an antique, anthropomorphic notion only slightly less naïve than the naïve version Voltaire felt bound to dispute.64 It was a symptom of an unresolved confusion in Voltaire’s mind, of a yearning for a palpable connection between science and purpose that even he could not quite shake off. But it was nothing more than that; it did not shape, and thus ruin, Voltaire’s philosophy of nature.
Diderot was in a rather more compromising position. He was reluctant to accept the cruel verdict of Newtonian science; he refused to believe in a nature largely empty, populated by cold, colorless corpuscles, and wholly indifferent to moral questions. “Man,” Diderot exclaims in an impassioned plea in his article “Encyclopédie,” “is the single place from which we must begin and to which we must refer everything”; remove “my existence and the happiness of my fellowmen, and what do I care about the rest of nature?” Man is, and must be, at the center of all things: “If we banish man, the thinking or contemplating being, from the face of the earth, this moving and sublime spectacle of nature will be nothing more than a sad and mute scene. The universe will cease to speak; silence and night will seize it. Everything will be changed into a vast solitude where unobserved phenomena take place obscurely, unobserved. It is the presence of man which makes the existence of beings meaningful.”65 All philosophes agreed that man is important; in fact, they insisted on it. Hume and d’Alembert, cool precursors of modern scientific objectivity, were wryly willing to concede that man is indeed nature’s masterpiece. But Diderot wanted more than that: he wanted man to merge into nature, and draw from it answers to his most pressing questions—What must I do? and, even more significant, Who am I? Diderot found it impossible to live with the teaching, implied by Newton and elaborated by eighteenth-century scientists, that science discloses what is and says nothing about what should be, that truth and beauty, truth and goodness, are wholly distinct. Nature, he insisted, in his Pensées sur l’interprétation de la nature, in his major articles in the Encyclopédie, in Le rêve de d’Alembert, is one vast interconnected organic whole in which the steps from matter to life, from science to ethics, from observation to admiration are not merely possible but proper and indeed essential. And so Diderot, looking back to the Stoics and ahead to the Naturphilosophie of the German Romantics, united what scientific philosophy was separating and asked of it what it could not give. “The distinction between a physical and a moral world,” he wrote about Jacques the Fatalist, and himself, “seemed to him empty of meaning.”66
For all these alarms and evasions, the drift of scientific philosophy toward moral neutrality created some anxiety among the philosophes but no panic; Diderot’s distrust of mathematics remained a relatively temperate minority report from the camp of progress.
Science failed to take the monstrous spectral shape it has taken since because, first of all, the really destructive possibilities of technology were still far in the future and almost beyond the imaginative reach of reasonable men. What is more, the philosophes—all philosophes—had an enormous investment in science as an ally in their war against religion; it was a commonplace among them that when science advances, superstition retreats. But beyond this, the philosophes found science genuinely admirable for its own sake. It was, with its unprecedented method, vastly superior to the alternative ways of seeking knowledge—the methods of theology and of metaphysics—that men had devised before. Not all new discoveries, especially in the biological sciences, stood above controversy. But that did not matter. They were subject to rules that permitted the testing of proposals, the confirmation and refinement of theories; scientific progress silenced disputes. Decade by decade, sometimes it seemed year by year, the area of agreement grew larger.
Educated men who had grown up amidst the clamor of philosophers and theologians found this astounding. The history of thought, as they well knew, was a history of discord, of endless, fruitless wrangles among the doctrinaire representatives of schools and sects, all claiming possession of infallible truth and denouncing their adversaries as fools or agents of the devil. Skeptics in ancient Alexandria had offered these pointless disputes as advertisements for their own school, which taught a courageous suspension of judgment. Some centuries later, Christian theologians in turn had exploited the quarrels of philosophical sects, and asked men to give up the vain games of reason and embrace the certainties of Christ. But, as the history of dogma proved over and over again, the theologians had been no better than the heathen philosophers: dispute and mutual abomination was everywhere, progress and certainty in knowledge nowhere. And now the sciences of nature promised a way to knowledge, and an accumulation of knowledge, to which all reasonable men could assent.
This is why the scientific method struck the eighteenth century as an invention unprecedented in its sheer magnificent effectiveness. In this new atmosphere, Voltaire suggested, the survival of the epithets “Newtonian” or “Cartesian” was misleading; scientific groupings were not contesting parties of hate-filled theologians: “What do names matter? What do the places matter where the truths were discovered? We are concerned with experiments and calculations, not with party chieftains.”67
The momentous manifestation of the scientific method—one of the most significant, most heartening realities in the world of the Enlightenment—promised a momentous consequence. If the scientific method was the sole reliable method for gaining knowledge in a wide variety of contexts, from the phenomena of the heavens to the phenomena of plant life, it seemed plausible and in fact likely that it could be profitably exported to other areas of intense human concern where knowledge was as primitive now, and disagreement as vehement, as it had been in physics a century before—the study of man and society. Even if facts and values were distinct, even if science was not the source of all past values, a bridge could be built between facts and values and the scientific method might become the instrument for the creation of future values.
As the men of the Enlightenment knew, Newton himself had seen this heady possibility. In the last of the famous queries with which he concluded his Opticks, he had noted that “if natural Philosophy, in all its parts, by pursuing this method, shall at length be perfected, the bounds of moral philosophy will also be enlarged.” It was a hint from the lips of the master, which the philosophes had every intention of exploring. J. T. Desaguliers, whose popularizations of Newton had wide circulation, proclaimed the imperial possibilities of Newton’s work shortly after Newton’s death in a poem winningly entitled “The Newtonian System of the World, the Best Model of Government.”68 Voltaire, with remarkable prescience, hoped to transfer the methods of the sciences to history: “Perhaps, soon,” he wrote, still a little tentatively, “what has already happened in physics will happen in the writing of history. New discoveries have led us to proscribe ancient systems. We will want to know mankind in the interesting detail which today forms the basis of natural philosophy.”69 Rousseau defended his procedure in his Discours sur l’inégalité by likening his speculative history of culture to the acceptable type of hypothesis current in modern physics. Lichtenberg made the significant observation that scientific method was even more important than a specific scientific discovery: “Inquiring into truth, we should always proceed so that some day even more enlightened ages will be able to take for their model not our beliefs but our procedure.”70 Much like d’Alembert, Condillac, whose methodological program is at the heart of Enlightenment philosophizing, proposed a reconstruction of philosophy on the model of the natural sciences. “Today,” he wrote—the year was 1749—“a few physical scientists, above all the chemists, are concentrating on collecting phenomena, for they have recognized that one must possess the effects of nature, and discover their mutual dependence, before one poses principles that explain them. The example of their predecessors has been a good lesson to them; they at least wish to avoid the errors that the mania for systems has brought in its train. If only all the other philosophers would imitate them!”71 For Condillac, scientific thinking was a model and a warning to all other kinds of thinking, the critical mind at its best and most effective, a potent objective instrument that good men could turn to good results.
Significantly enough, it was David Hume, the very philosopher who had insisted on the strictest possible separation of facts and values, who also insisted on the social relevance of scientific enquiry. It is well known that Hume advertised his Treatise of Human Nature to be “An Attempt to introduce the experimental Method of Reasoning into Moral Subjects,” and his Introduction to the Treatise is a manifesto of the Enlightenment’s critical positivism, a call to have objective knowledge serve human ends. “ ’Tis evident,” Hume argues, “that all the sciences have a relation, greater or less, to human nature; and that however wide any of them may seem to run from it, they still return back by one passage or another.” After all, even “Mathematics, Natural Philosophy, and Natural Religion” are to some degree “dependent on the science of MAN”; they “lie under the cognizance of men, and are judged of by their powers and faculties.” If this holds for these abstruse disciplines, how much more must it hold for the “other sciences,” like logic, ethics, aesthetics, and politics, “whose connexion with human nature is more close and intimate”? Human nature is the capital or center of the philosophical sciences, which “being once masters of, we may every where else hope for an easy victory. From this station we may extend our conquests over all those sciences, which more intimately concern human life.” Hume conceded that the establishment of a reliable science of man was a difficult task; it depended on the accumulation of “experience and observation,” and, unlike the natural sciences, the science of man could not artificially multiply its observations through experiment. Still, it was possible to “glean up our experiments in this science from a cautious observation of human life, and take them as they appear in the common course of the world, by men’s behavior in company, in affairs, and in their pleasures.” The modern philosopher had every right to be confident: “Where experiments of this kind are judiciously collected and compared, we may hope to establish on them a science, which will not be inferior in certainty, and will be much superior in utility to any other of human comprehension.”72 Even if he did not always say what he meant, Hume always meant what he said: the science of man was possible and would be immensely useful. That is why the men of the Enlightenment were ultimately not afraid of science; it was not merely their best, but their only, hope for the knowledge that would give man both abundance and freedom. More than a century before Freud—the greatest scientist of man the world has known and the philosophes’ most distinguished disciple in our century—the philosophes believed, as he would put it later: “No, science is no illusion. But it would be an illusion to suppose that we could get anywhere else what it cannot give us.”
1 Voltaire to Cideville (April 16, 1735). Correspondence, IV, 48–9.
2 Vie de Voltaire, in Voltaire: Œuvres, I, 214. Some scholars, including Gustave Lanson, have objected that this is a doubtful assertion (see Lanson: Voltaire [1906], 73–4), but it is not wholly without merit.
3 Lettre XII, Lettres philosophiques, I, 153. And see Voltaire’s letter to the abbé d’Olivet, October 18 (1736): Newton, he writes there, was “the greatest man who ever lived.” Correspondence, V, 281.
4 D’Alembert: Discours préliminaire, in Mélanges, I, 137. Voltaire: to the Académie française, in Œuvres, VII, 335.
5 It would, of course, be oversimplifying his thought to call Fontenelle simply a Cartesian; while he never abandoned Descartes’s physics and his famous tourbillons, he was sympathetic to Newton’s method and, as his eulogy makes plain, aware of Newton’s stature.
6 History of England … (edn. 1780), VIII, 326.
7 “Leben des Herrn Jacob Thomson,” Theatralische Bibliothek (1754), in Schriften, VI, 61.
8 Notebooks, 63.
9 Quoted in Brooke Hindle: The Pursuit of Science in Revolutionary America, 1735–1789 (1956), 80.
10 Lettre XIV, Lettres philosophiques, II, 2.
11 Delille: Œuvres, (1824), IX, 7, quoted in Ruth T. Murdoch: “Newton and the French Muse,” JHI, XIX, 3 (June 1958), 324.
12 Quoted in Murdoch, 326.
13 Haller: Versuch schweizerischer Gedichte (11th edn., 1777), 157.
14 “Aus einem Gedicht an den Herrn Mxxx” (fragment of 1748), Schriften, I, 243, 245.
15 See The Rise of Modern Paganism, 127–59.
16 Pierre Brunet: Les physiciens hollandais et la méthode expérimentale en France au XVIIIe siècle (1926), passim.
17 E. W. Strong: “Newtonian Explications of Natural Philosophy,” JHI, XVIII, 1 (January 1957), 68.
18 Brunet: Les physiciens hollandais, 93.
19 Ibid., 103.
20 In a note of 1756, added to his Épître à la Madame du Châtelet sur la philosophie de Newton (1736), in Œuvres, X, 302 n. Interestingly enough, Voltaire’s malicious estimate of Maupertuis survived Maupertuis, and even Voltaire. In his biography of Voltaire, published in 1787, Condorcet perpetuated the old slanders by calling Maupertuis an intelligent man but a “mediocre scientist and even more mediocre philosopher.” In Voltaire: Œuvres, I, 231.
21 Lettre XIV, Lettres philosophiques, II, 1. As early as 1730, Voltaire had added some Newtonian verses to a revised version of his epic, the Henriade, but hedged his position with a disclaimer in the footnotes: “Whether we accept Mr. Newton’s attraction or not, it is still certain that the heavenly spheres seem to attract or repel each other.” Œuvres, VIII, 170, quoted in Murdoch: “Newton and the French Muse,” 325.
22 Éléments de la philosophie de Newton, in Œuvres, XXII, 402.
23 “Réponse aux objections principales qu’on a faites en France contre la philosophie de Newton” (1739), in Œuvres, XXIII, 72.
24 “Some Considerations Touching the Usefulness of Experimental Philosophy” (1663), quoted in Martha Ornstein: The Role of Scientific Societies in the Seventeenth Century (3rd edn., 1938), 58–9.
25 See The Rise of Modern Paganism, 314–17: Thomas Sprat, whose famous History of the Royal Society (1667) was a vigorous defense of the new philosophy, later became a bishop; Robert Boyle left £350 in his will endowing lectures defending Christianity; Joseph Glanvill and after him Cotton Mather were at once champions of modern science, Fellows of the Royal Society, and believers in witchcraft.
26 See Newton’s Philosophy of Nature, 41.
27 Éléments de la philosophie de Newton, in Œuvres, XXII, 403–4.
28 Lettre VII, Lettres philosophiques, I, 72.
29 Leibniz to Caroline, Princess of Wales, November 1715. The Leibniz-Clarke Correspondence, ed. H. G. Alexander (1956), 11–12.
30 Clarke’s first reply to Leibniz (November 26, 1715). Ibid., 14.
31 Leibniz’s fifth paper. Ibid., 81.
32 Éléments de la philosophie de Newton, in Œuvres, XXII, 408.
33 See The Rise of Modern Paganism, 316.
34 Discours préliminaire, in Mélanges, I, 130. One distinguished scientist, at least, Albrecht von Haller, demurred: there is no evidence, he argued, that Newton or Locke learned anything from Descartes or that Descartes “opened the way to true philosophy.” Tagebuch, 2 vols. (1787), I, 112, 381–2.
35 See above, 6, and The Rise of Modern Paganism, 310–13.
36 John Tulloch: Rational Theology and Christian Philosophy in England in the Seventeenth Century, 2 vols. (1872), I, 373; see ibid., II, 369.
37 Alexandre Koyré: Newtonian Studies (1965), 54 n., 79 n.
38 Œuvres, XIII, 371, quoted by Aram Vartanian as the motto to his Diderot and Descartes: A Study of Scientific Naturalism in the Enlightenment (1953), 2.
39 Lettre XIV, Lettres philosophiques, II, 1–6.
40 Œuvres, I, 199–200 (see The Rise of Modern Paganism, 139–40).
41 Discours préliminaire, in Mélanges, I, 130–6.
42 Éléments de la philosophie de Newton, in Œuvres, XXII, 404.
43 Œuvres, II, 11.
44 Discours préliminaire, in Mélanges, I, 158.
45 Buffon: Histoire naturelle, in Œuvres philosophiques, ed. Jean Piveteau (1954), 7, 9.
46 Ibid., 31.
47 Ibid., 7.
48 Ibid., 15.
49 Ibid.
50 Ibid., 22.
51 Ibid., 24.
52 Ibid., 26.
53 Horace Walpole thought Buffon the only philosophe who was amiable and agreeable (see The Rise of Modern Paganism, 10); on his visits to Paris, David Hume numbered him among his group of philosophic friends, which included d’Alembert, Helvétius, Holbach, Suard, Marmontel, Diderot, Duclos, and Galiani (see Hume to Hugh Blair [December 1763]. Letters, I, 419; and Hume to Morellet, July 10, 1769. Ibid., II, 205).
54 March 12, 1751; in Buffon: Œuvres, 108.
55 Francis C. Haber: “Fossils and the Idea of a Process of Time in Natural History,” in Forerunners of Darwin, 1745–1859, ed. Bentley Glass et al. (1959), 236.
56 “Expérimental,” in The Encyclopédie, 79. The Cartesians, it seems, were rather slower than the Newtonians in adopting the new usages.
57 Richard Watson: Anecdotes of the Life of R. W. written by himself at different intervals, and revised in 1814 (1817), quoted by F. Sherwood Taylor: “The Teaching of the Physical Sciences at the End of the Eighteenth Century,” in Natural Philosophy Through the 18th Century and Allied Topics, anniversary number of the Philosophical Magazine (1948), 162.
58 Voltaire to Cideville (April 16, 1735). Correspondence, IV, 49.
59 Notebooks, 361.
60 Sengle: Wieland, 41.
61 Pensées sur l’interprétation de la nature, in Œuvres, II, 38.
62 Ibid., 11.
63 Voltaire to d’Olivet, October 20, 1738. Correspondence, VII, 412.
64 “End, Final Causes,” Philosophical Dictionary, I, 271. Voltaire was not alone: Adam Ferguson thought the evidence for final causes in nature obvious and overwhelming (Gladys Bryson: Man and Society, 36–7). For Buffon’s rejection, see Œuvres, 258.
65 “The Encyclopédie,” 56.
66 See Charles C. Gillispie: The Edge of Objectivity: An Essay in the History of Scientific Ideas (1960), 181.
67 “Réponse aux objections principales qu’on a faites en France contre la philosophie de Newton,” in Œuvres, XXIII, 74.
68 See W. K. Wimsatt, Jr.: Philosophic Words (1948), 100.
69 “Nouvelles considérations sur l’Histoire” (1744), in Œuvres historiques, 46.
70 J. P. Stern: Lichtenberg: A Doctrine of Scattered Occasions (1959), 37.
71 Traité des systèmes, in Œuvres, I, 127. It is this temper that permitted philosophes in Europe (and, as the writings of Madison show, America as well) to speak of the science of morals or the science of politics. See below, chap. vii and chap. ix, section 1.
72 A Treatise of Human Nature (1739–40; edn. 1888), xix-xxiii.