An optical illusion

Was the 18th century just a dull trough, when dwarves were perched on the shoulders of the giants of the 17th century's scientific revolution? Far from it, argues Roy Porter, it is our history of the period that is inadequate and in need of more research. It was in fact an innovative time, peppered by disputes, jealousies and fierce battles over the ownership of discoveries.

Was ist Aufklarung?" asked Immanuel Kant back in 1784, and the issue has remained hotly debated ever since. Not surprisingly, therefore, if we now pose the further question, "What was Enlightenment science?", the uncertainties are just as great - but here the controversies assume a different air.

Studies of the Enlightenment proper paint the age of reason in dramatic hues and reflect partisan viewpoints: some praise it as the seedbed of modernity, individuality and liberty, others condemn it as the poisoned spring of authoritarianism and alienation. Eighteenth-century science, by contrast, has typically been portrayed in more subdued tones. To most historians it lacks the heroic quality of what came before - the martyrdom of Bruno, Galileo's titanic clash with the Vatican, the "new astronomy" and "new philosophy" of the "scientific revolution", the sublime genius of a Descartes, Newton or Leibniz.

After that age of heroes, the 18th century has been rated dull, a trough between the peaks of the "first" and the "second" scientific revolutions, a lull before the storm of the Darwin debate and the astounding breakthroughs of 19th-century physics. At best, dwarves were perched on giants' shoulders. "The first half of the 18th century was a singularly bleak period in the history of scientific thought" and the age was marked by "an element of dullness": verdicts like this have been ten a penny.

Given such judgements, it is hardly surprising that the history of 18th-century science has simply been neglected. It is a long time since a weighty general account appeared. The Beginnings of Modern Science: From 1450 to 1800, a work edited by Rene Taton that appeared in French in 1958 and in English translation seven years later, was the last synthetic text that included a substantial section on the 18th century. But that was essentially a compilation and its interpretations now appear horribly dated, mainly on account of their pervasive positivism: "18th-century science", we there read, "was largely responsible for the rise of rationalism and for the shedding of much theological lumber".

This lack of modern texts may be regarded, in part, as a byproduct of the vagaries of historical periodisation. The original edition of Rupert Hall's pioneering The Scientific Revolution, 1500-1800 (1954) thus nominally envisaged that "revolution" as going right up to 1800, though disproportionately little space was actually devoted to the 18th century. In his 1983 rewriting of the book, Hall chose to truncate his terminal date to 1750, and devoted even less space to the 18th century - just ten pages out of 350.

Nor is it surprising that muted terms such as "consolidation" have come to mind for characterising the natural sciences in the 18th century. "When Newton died (17), the great creative phase of the scientific revolution was already finished," maintained Hall, if stressing that, "its acceptance and assimilation were still incomplete." Casting the job of "completion" in a positive light, however, Margaret Jacob has pictured the century as the era when "scientific knowledge became an integral part of western culture", or in other words became "public knowledge".

"Acceptance" and "assimilation" may be apposite epithets for 18th-century science, especially if they are intended to highlight transformative processes. The incorporation of science into modern mindsets was at least as momentous as the dazzling innovative leaps of a Kepler or Harvey; it certainly presents the historian with taxing problems to explain.

It is important, in any case, that talk of "assimilation" and "consolidation" should not convey the false impression that all the great breakthroughs of early modern natural science had already been achieved by 1700. We should not minimise the still inchoate condition in 1700 even of those sciences intimately associated with Newton, Huygens, Leibniz and the other pioneers of a new mathematical physics - nor, indeed, should we forget that, at the turn of the century, Leibniz still had 16 years to live and Newton , or that Newton's Opticks had not even been published. The Lucasian professor bequeathed as many problems as solutions and 18th-century astro-physicists were still making striking innovations, observational, computational and theoretical.

Even more remarkable, perhaps, and often interlinked, were contemporary developments in mathematics. To many European practitioners, Newton's methods appeared radically wanting. While British mathematicians were treading water, hampered by the clumsy Newtonian "fluxion" procedures, the Bernoullis, Maupertuis, Euler, Clairaut, d'Alembert, Lagrange, Laplace and other continental mathematicians made brilliant advances. Innovative techniques in analysis spurred the application of mathematics to many problems, including the motion of rigid bodies, vibration, hydromechanics and tension; and conservation laws were developed, which theorised the cosmos in terms alien to the cosmology of divine intervention championed by Newton, pointing towards Laplace's nebular hypothesis -the theory that the universe evolved from an inchoate mass.

Moreover, the headway made by 18th-century mathematics was far from confined to technical achievements. In the "Preliminary discourse" to the Encyclopedie (the great radical reference work of the philosophes), philosophe and mathematician Jean d'Alembert proclaimed mathematics the basis of all physical science. Corroborating Jacob's claim that in the 18th century "scientific knowledge became an integral part of western culture", historians have stressed the permeation of the "esprit geometrique" (or "calculating spirit") into everyday life, from life insurance to gambling.

Nor was that all. As signalled 50 years ago by Herbert Butterfield's notoriously question-begging chapter heading, "The postponed scientific revolution in chemistry" in The Origin of Modern Science, 1300-1800, one field that proved exceptionally innovative in the 18th century was chemistry, in particular the dramatic recognition that the atmosphere was not a uniform physical state but a mix of separate gases with distinct chemical properties. Lavoisierian chemistry arguably constituted the concluding chapter of the "scientific revolution".

Meanwhile, new specialities were taking shape, so that, by the turn of the 19th century, terms such as geology and biology had been minted and were soon to become standard labels for emergent disciplines. Aspects of the physical sciences amenable to experimental inquiry took striking steps forward; and understanding of magnetism and electricity changed radically between 1700 and 1800. It ceased to be plausible to view physics, in the traditional, Aristotelian manner, primarily as a branch of philosophy: by 1800 true physics meant experimental physics. In well-ploughed fields of inquiry, like natural history, remarkable changes may be seen. It was at this time, for instance, that plant sexuality was first fully established as the foundation for botanical thinking within the new taxonomic system developed by Carolus Linnaeus. The first evolutionary theories were advanced, associated (obliquely) with Buffon and (explicitly) with Erasmus Darwin and Jean Baptiste Lamarck. It is not crudely whiggish to insist that theorists of life were finding that the static, hierarchical and Christian "chain of being" no longer possessed explanatory power and that the living needed to be conceptualised within a more dynamic framework and an extended time-scale. Wherever one looks, there was, during the 18th century, no stalling in scientific theory or practice. But it would be wrong to imply that 18th-century science deserves study solely for its conceptual innovativeness. And this leads us back to the notion of "consolidation".

Gradually, unevenly, but, perhaps, inexorably, the production of knowledge about nature and the casting of discourse in natural terms were playing increasingly prominent roles in culture, ideology and society at large. Natural philosophers and historians were claiming their place in the sun with churchmen and humanists. Gentlemen of science - and some ladies - were admitted into the republic of letters, changing its complexion. Governments were increasingly employing experts as administrators, explorers, civil and military engineers, propagandists and managers of natural resources. Science was held to provide the knowledge base necessary for "enlightened absolutism", above all through statistics (statistik: state information) and political arithmetic; scientific experts would be brokers in the Baconian marriage of knowledge and power.

Looking back, historians might variously interpret such developments as progressive or as acts of social policing; either way, natural knowledge acquired an enhanced public prominence during the last years of the ancien regime, mediating values and visions. Despite their radically disparate philosophical allegiances, the deeply pious Joseph Priestley and the philosophe Condorcet were both looking during the French revolutionary era to a future society transformed by scientific discoveries and scientific rationality, one marked not merely by material improvements but by the perfectibility of man.

Some measure of science's growing authority is evident in the vehemence of the romantic revolt against it. The anti-science satires of the Augustan era - poking fun at virtuosi who peered down telescopes and mistook flies for elephants on the moon - give the impression that, about 1700, humanists still hardly discerned a serious scientific "threat". Indeed, many men of letters were notably fulsome about scientific advances: Newton, pure Intelligence, whom God To Mortals lent, to trace his boundless Works From laws sublimely simple.

sang James Thomson. Humanists were prominent in the dissemination of the sublime truths of the new science. In 1686, for instance, Bernard de Fontenelle produced his famous dialogue On the Plurality of Worlds - the first work in France that made it both intelligible and entertaining to the general reading public. The man of letters thus conferred his blessing upon natural science, preparing the way, so to speak, for the cultural displacement of Christianity.

In stark contrast, there was something quite new in William Blake's later venom against the infernal trinity of Bacon, Locke and Newton, as also in Charles Lamb's notorious toast to the "confusion to mathematics", or, in its subtler manner, Goethe's formulation of an alternative to the mechanistic reductionism he deplored in Newtonianism. Mechanical science, judged romantic critics, was turning into a Frankenstein's monster.

Perhaps the most telling index of this 18th-century "consolidation" of science is its embodiment in permanent institutional form. In earlier generations, natural knowledge had possessed few stable specialist platforms, and none unique unto itself. Most adepts had had to carve out a personal niche, be it at court, in the church, or in academe; a few, like Tycho Brahe, had been able to draw on private wealth, while some, like Paracelsus, had lived hand to mouth. Though educational foundations had given a modicum of encouragement to scientific and medical studies, the natural sciences could never become dominant in the traditional university system, whose rationale lay in training the clergy or educating gentlemen or civil servants.

The precariousness of traditional institutional backing for science was alleviated during the 18th century. Many European rulers, with an eye to both practicality and prestige, made it their business to create state support programmes for savants, through such official bodies as the French Academie Royale des Sciences. Scientific academies, notably those in Paris, St Petersburg and Berlin, established clutches of permanent, state-funded posts for men of science. In addition, scientific societies sprang up, national and local, formal and unofficial, practical and ornamental, closed and open. About 100 had sprouted by the close of the century, from Boston to Brussels, through which the scientific enterprise became newly solidified.

Leading lights in such academies also played a part in spreading and seeding the natural sciences, for example among the wider circles of the salons. In France this was initially thanks to the efforts of Fontenelle, the perpetual secretary of the French Academy from 1699 to 1741, and also to Voltaire, who popularised Newtonianism for French readers.

And if science was a growing presence within what Jurgen Habermas has styled the "public sphere" - in societies and salons, in lecture courses and museums - it was equally becoming established in the mind, as an ideological force and a prized ingredient in the approved cultural diet. Controversies rage among historians as to how best to interpret the outreach of science: "diffusion", "trickle down" and "social control" explanatory models have all been proposed. "Supply and demand" models clearly beg many questions, but they at least have the virtue of recognising that, in the advanced regions of Europe, something like a marketplace in ideas had emerged. Consumers might buy into whichever aspects of science they chose, be they demonstrations in chemistry, or microscopes, or popular books such as Algarotti's Newtonianism for the Ladies.

Within the Enlightenment project, the discourses of philosophy, poetry, religion and politics appropriated the scientific methods and models associated with Bacon and Descartes, Galileo and Gassendi and, above all, Newton. There were Newtonian poems galore, Newtonian theories of government, corpuscularian models of society, of political economy, of the mind and the passions, disseminated by magazines and spread through provincial assemblies from Newcastle to Naples. Although such revisionist historians as J. C. D. Clark have questioned the importance of natural science to the consciousness of the age, E. P. Thompson was surely nearer the mark in maintaining that "the bourgeois and the scientific revolutions in England ... were clearly a good deal more than just good friends"; the same holds for the relations between science and polite society in the Dutch Republic, the German principalities, the Italian duchies and the Swiss cantons.

Though the Enlightenment assuredly involved far more than the uptake of natural science, it would have been unthinkable without the surge of confidence in man's powers over nature conferred by the new philosophy. For the philosophes, scientific inquiry was the new broom par excellence that would sweep mystifications and obscurantism aside, removing the mumbo-jumbo of the church and the "feudal" ways that kept the masses poor, hungry and oppressed - that much is evident from a glimpse at any of the 28 volumes of the Encyclopedie. Indeed, perhaps the prime impulse behind the encyclopedic project was dissemination of scientific knowledge. The increasingly rapid accretion of such information created the need, or provided the rationale, for new encyclopedias and for updated editions of the old.

Promoters of science and Enlightenment should not, to be sure, be taken at their own estimations. The natural sciences always came gift-wrapped in ideology. The voice of "science" might bolster elite culture, while discrediting the beliefs and behaviours of the pious, the poor and the plebs, of women and the marginalised. In particular situations, science declared that belief in witchcraft was mere superstition; in others it affirmed the superiority of the white man, or pronounced upon the hysterical tendencies of the female nervous system. The new techniques - statistical enumeration, biopolitical surveys - applied to specific "social uses", staked claims to authority on the basis of the physical sciences. Nor were the weapons of science available only to "progressives". In his Essay on the Principle of Population (1798), "Parson" Malthus believed he could demolish the foolish perfectibilism of the French revolutionaries with some tabulations of death data and a simple equation.

It was Newton himself who ventured in Opticks (1704) that by perfecting natural philosophy, "the bounds of Moral Philosophy will also be enlarged". Projects taking their cue from this declaration enjoyed great prestige; it was not only David Hume who aspired to be the "Newton of the moral sciences". Hence it comes as no surprise that, by the 1790s, Edmund Burke, recoiling from the accursed atrocities of the French revolution, could lament that "the age of chivalry is gone - that of sophisters, economists, and calculators, has succeeded; and the glory of Europe is extinguished for ever".

Addressing such developments - the rise of those very economists and calculators - some of the most important recent work on Enlightenment science has explored the recruitment of science as a disciplinary and regulative authority. Michel Foucault analysed the role played by scientific rationality in creating new regimes and technologies of power, often for the management of populations and environments. Feminists have maintained that the models and metaphors of mechanical science lent themselves to doctrines of male domination. E. P. Thompson showed how the new science of political economy was used to discredit the traditional "moral economy", while many studies have explored how natural knowledge was conscripted to nullify popular and folk knowledges.

The potency of science and its ideological uses - or "abuses" - must not, however, be exaggerated, and we must be careful not to predate its hegemony; after all, the English language had no need for the very word "scientist" till well into the next century. It would be anachronistic to imply a grand canyon or a polarity between the investigation of nature and the contemplation of God, just as it would be simplistic to assume a preordained transition from a religious cosmos, in whose workings a personal God intervened, to a later naturalistic one, governed exclusively by natural laws. Instead of any such teleological or evolutionary readings, the challenge the scientific presents to the historian lies in explaining uneven development and resistance. After all, the French revolution closed down the Academy of Science, guillotined two of the nation's premier men of science, Lavoisier the chemist and Baily the astronomer, and hounded to death science's leading spokesman, Condorcet. Science, in other words, wasn't in everyone's eyes the spirit of the future mounted majestically on an iron horse; it was a resource with uses, and foes no less than friends.

Central to the problem of comprehending 18th-century natural science is what species of knowledge it was supposed to constitute. The term typically deployed in the early modern era for such inquiries was natural philosophy - as in Newton's Principia Mathematica Philosophiae Naturalis (1687) - this being regarded as a system of concepts meditating between matters of fact and philosophy, and leading, by implication, "through Nature up to Nature's God". The term and the ideal it embodied remained widespread. But a balkanisation of specialist disciplines was undermining the notion of a unifying natural philosophy.

Some 20 years ago Susan Cannon griped at our ignorance about even the basics of 18th-century science: "For the history of science and the history of ideas in the 18th century you can trust almost no one. The amount of 'hard' history of science for that period is so lacking that one simply leaps from Newton in optics to Young in optics. It is no reproach to my friends who are trying to do something with the 18th century to tell them that their labours have not yet reached the point at which a 19th-century historian can confidently go ahead from the stable platform they had erected."

Now is the time for Enlightenment science to be rethought.l Roy Porter is professor of the social history of medicine, Wellcome Institute, London.