Robert Hollinger, in his essay "What is the Enlightenment?," notes the centrality of science to the "Enlightenment project," as he defines it, offering as one of the four basic tenets that constitute the "basic ideas of the Enlightenment" the view that "only a society based on science and universal values is truly free and rational: only its inhabitants can be happy." (Smith 1998, p. 71). As Smith (1998) says generally about the Enlightenment period, "Scientific knowledge came to be seen as an instrument for securing control over the human condition and for making it better." (p. 56).
But to what degree did the Enlightenment have an actual effect on science and its practice? I will look at three areas -- the philosophes, the "science of man," and the Deist religion -- in order to define how the Enlightenment culture affected the development of the scientific method.
Smith notes that Diderot's plan to codify knowledge generally in a single encyclopedia was the beginning of the systematization of knowledge, in an attempt to make it universally available. But Henry (2004) credits Diderot and the philosophes with first making such central claims on behalf of science as a force in culture as we are accustomed to hearing nowadays: "…it was the Enlightenment philosophes who took up the science of the preceding age and helped to establish it as the dominant force in Western culture" (p. 10). To a certain degree, this represented a covert form of revolt against the established religion: in Diderot's France, this was the Roman Catholic church, of whom his fellow philosophe Voltaire would frequently remark "Ecrasez-l'infame!" (which translated to something like "Destroy this infamous institution"). Jimack (1996) notes the anticlerical stance of Diderot and the philosophes: "the Church came to be seen by many philosophes as the arch enemy of mankind, and in the articles of the Encyclopedie (as well as in many other works of the period), it was often represented not just as an obstacle to progress, but as a powerful agent of repression and restriction, an instrument of the forces of darkness which had for centuries sought to submerge the forces of enlightenment." (p. 188). To the degree that earlier science had often been hampered -- as with Galileo -- by the interference of religious authorities, this may be seen as real progress and encouragement for the establishment of science.
But it is important to stress that, within the Enlightenment period, science did not necessarily have the reputation of being religion's enemy. For example, Sir Isaac Newton is thought of as the father of modern physics, and in addition made numerous other contributions (optics, gravitation, calculus) that to some degree Newtonian science represents the largest single leap of the Enlightenement period. Thomas Kuhn, in his famous study The Structure of Scientific Revolutions (Third Ed., 1996), credits Newton with providing a complete paradigm shift (and the Newtonian paradigm would hold until Einstein). "By the early eighteenth century those scientists who found a paradigm in the Principia took the generality of its conclusions for granted, and they had every reason to do so" (p. 30). Yet it comes as something of a surprise to those of us who are aware of today's physicists -- like Stephen Hawking -- or earlier 20th century figures to realize that, as Mamiani (2002) notes, Newton authored numerous "theological manuscripts…concerned principally with two subjects: the interpretation of the prophecies of the Apocalypse and Daniel, and the history of the early Church," where his commentary on Daniel runs to one million words on its own (p. 387). But it is only by our contemporary standards that this represents any disjunction: Israel (2006) notes flatly that scientific research in the Enlightenment period was rather conveniently held up as proof of God's Handiwork' Israel writes: "Claiming Sir Isaac's science as the best way to demonstrate divine providence, Newtonians built a highly integrated physico-theological system encompassing not only science, religion and philosophy but also history, chronology, Bible criticism, and moral theory which became vastly influential throughout eighteenth-century Europe and America" (p. 203). Karen O'Brien (2009) notes the basic pattern where, in the Enlightenment period, religion was seen as part of the overall scientific conception: "understanding of man's aspiring mind in turn leads to an inductive knowledge of God's existence, itself the highest form of rational self-awareness, and it is this higher 'science' that acts as the motivational force behind all material and artistic progress" ("These Nations," p. 294). And Stewart (2004) notes that Newton was always particularly involved in religious issues, even moreso than his own "natural philosophy" (as he termed his scientific activities) which he considered secondary, or possibly as identical to the first: Stewart remarks upon "Newton's own pronouncement in 1713, in the second edition of his Principia…that 'God does certainly belong to the business of experimental philosophy'." (p. 236). It is also worth noting that Newton did not make any significant contribution to scientific method -- as opposed to his tremendous contributions to science, his experiments (such as the refraction of light by a prism) proved very hard to replicate for his contemporaries. And Newton's own method was derived from the earlier English Renaissance figure of Bacon: Newton's milieu, in the description given by Rogers (1996), was "much coloured by the programme for the investigation of nature that Bacon had advocated in the early part of the century" (p 36).
But if the scientific method did not destroy theology, it did give birth to a host of other academic disciplines which would soon be jockeying for attention alongside theological study. Wood (2003) stresses the way in which these developments in science and medicine had helped the birth of the new social sciences (as we would term them): "The 'new science' born in the Scientific Revolution of the seventeenth century also provided methodological inspiration for the 'science of man' constructed in the Scottish Enlightenment…Science and medicine were central to, and in some cases the driving force behind, the intellectual changes encompassed by the term 'the Scottish Enlightenment" and hence were instrumental in shaping modernity in Scotland as elsewhere." (p 95) As Knellwolf (2004) states about these researches -- using the term that the Enlightenment itself preferred, "the science of man" -- in modern terms which emphasize the breadth of achievement in the Enlightenment, "The science of man was the precursor of a number of academic disciplines familiar today under such labels as the philosophy of mind, cognitive psychology, anthropology, ethnology and sociology, disciplines which assumed their modern forms during the nineteenth century." (p. 194). As for "the science of man," Thomson (2008) credits Hume with introducing the term, but also notes the claims he made for it: "The central preoccupation with human nature, or 'the science of man' -- which Hume in the Introduction to A Treatise of Human Nature called 'the only solid foundation for the other sciences' -- presupposed a concern with complex and dangerous scientific and theological issues" (p. 2). But Christa Knellwolf (2004) notes that our contemporary terms and definitions may not necessarily apply here: she writes that "…in the eighteenth century…the term 'science' did not yet have its twenty-first-century sense, but was still more or less equivalent to the Latin scientia, so that the 'science of man' can essentially be paraphrased as knowledge of man" (p 194). In any case, these new disciplines colored the Enlightenment differently by refusing to conform to its optimistic assumptions. Adam Smith's 1776 Wealth of Nations would found the modern social science of economics, but it earned the nickname of "the dismal science" due to Smith's shockingly amoral conclusions. And O'Brien (2009) notes that this scientific application to questions of demographics was also occasionally not so optimistic as the standard Enlightenment scientism with the theories of Thomas Malthus, who had worked out the mathematics of exponential growth as it applied to human populations: this led to astonishingly gloomy predictions, but also (as O'Brien puts it) "Malthus's 1798 Essay represented an intervention in the Scottish Enlightenment account of social progress to the extent that it treated population growth more as an effect of biology (especially female biology) than of institutional or economic arrangements" (Women, p 225).
In conclusion, it is worth noting that these different aspects of the birth of the scientific method in the Enlightenment -- which may alter our standard depiction of the period -- are well in line with historical trends which had been building substantially before the actual time. Sir Isaac Newton famously claimed that, if he had been able to see farther than most in his own scientific work, it was only because he was "standing on the shoulders of giants," and indeed the long trail of the past manages to link most Enlightenment trends -- including the contradictory implications for religion that I highlighted -- with much earlier phenomena. Certainly the Enlightenment was the fullest efflorescence of an informational revolution that had begun with Johannes Gutenberg's introduction of moveable type and book-publication to continental Europe in…