In 1550, the Italian art historian Giorgio Vasari, who coined the word Renaissance, described the painters, sculptors, and architects of his era in a series of biographies as “rare men of genius.” One hundred and seventy-fi ve years later, another cultural commentator, the English poet Alexander Pope (1688–1744), extended this judgment to a mathematician and physicist, Isaac Newton (1642–1727), offering a brief couplet as part of the outpouring of eulogies right after Newton’s death: Nature, and Nature’s laws lay hid in night, God said Let Newton be! and all was Light . Newton himself was not so sure about this, writing in a letter to fellow scientist Robert Hooke in 1675, “If I have seen further [than certain other men] it is by standing upon the shoulders of giants.” In terms of intellectual development, the period from Vasari’s biographies to Pope’s poem is often referred to as the “Scientifi c Revolution,” a phrase invented in the nineteenth century to label this time of change in the way learned individuals approached, conceptualized, and studied the natural world. Like the Renaissance, the Scientifi c Revolution is not an event with a specifi c beginning and end, but a series of developments. Whether these changes were as Pope envisioned – sudden bursts of genius that altered everything – or as Newton described them – steady advances that built on earlier ones – is still a matter of debate, however. Among recent scholars, one of the most infl uential voices arguing in favor of dramatic change was the philosopher and physicist Thomas Kuhn (1922–96). In The Structure of Scientifi c Revolutions (1962), Kuhn proposed that people studying the natural world (what we would now term scientists) work within a specifi c world-view until there is too much data that contradicts that world-view, but no one theory that explains all the contradictions. At that point, someone – often from outside the establishment in which scientists normally work – proposes a radically different world-view, what Kuhn calls a “paradigm shift.” This new paradigm does not just add to earlier knowledge, but makes people who accept it view the world in a completely new way. Kuhn uses a number of scientifi c developments from the sixteenth through the eighteenth centuries as examples of such paradigm shifts, the most dramatic of which was the shift from an earth-centered to a sun-centered view of the cosmos. Since then, other historians of science have argued that Kuhn overemphasized big changes. The major thinkers of the Scientifi c Revolution, they point out, continued to accept many ideas because they appeared in ancient sources, and built on the work of medieval scientists. Kuhn’s argument has been very powerful, however, and his phrase “paradigm shift” is now so pervasive in business, government, and other realms of life that it has become a joke, particularly when coupled with “thinking outside the box.” Whether we call it a paradigm shift or not, the idea that there was a radical break in the world-view of educated Europeans in the seventeenth and eighteenth centuries is a powerful one, and extends beyond the realm of science. Pope uses the word “light” to praise Newton because many of Newton’s discoveries involved light and optics, and because Pope saw him as setting a pattern in which the “light of reason” is used to explore the universe. Thinkers in the eighteenth century described their enterprise as “Enlightenment,” the principles of which the German philosopher Immanuel Kant (1724–1804) summarized in 1784 in the phrase: “ Sapere aude ! [Dare to know!] Have the courage to use your own understanding!” 1 The Enlightenment was a self-conscious intellectual movement in the same way as the Renaissance had been. Renaissance thinkers envisioned themselves as part of a rebirth of classical culture, while Enlightenment thinkers asserted that knowledge could free them from the ancient past. The “light of reason,” they argued, could be used against the darkness of prejudice, superstition, blind belief, ignorance, tyranny, and injustice. The classical past was not uniformly rejected, as architects, writers, and even political theorists used Greek and Roman models for their works, but it was to be emulated selectively and deliberately, and not regarded as superior. This questioning of received wisdom extended to the realm of religion, as thinkers challenged the cultural and institutional authority of the Christian churches and criticized many beliefs and practices as “superstition.” Thinkers in the Enlightenment – those in France called themselves philosophes – regarded the development of science as one of the most important sources of their own intellectual liberation, and also looked to the writings of several seventeenth-century thinkers who emphasized the role of reason and observation as challenges to received wisdom, including René Descartes and John Locke. They took ideas and methods from the realm of the natural sciences and applied them to the social sciences, seeking to fi nd rules and laws that applied to human beings in the same way that the law of gravity or other of “Nature’s laws” applied in the physical world. This search for order did not lead to a single ideology, for there was great diversity of opinion on a range of issues, but to general consensus around a set of common values: reason, religious toleration, progress, liberty, utility, and skepticism toward traditions and dogmas. The Scientifi c Revolution and the Enlightenment were not the only intellectual and cultural developments in seventeenth- and eighteenth-century Europe, which also saw new forms and themes in art, literature, and music. All of these were supported by the centralizing monarchs we discussed in chapter 9 , for intelligent rulers recognized that having educated and talented writers, scientists, philosophers, musicians, and artists at their courts only enhanced their stature. In return for fl attering dedications in scientifi c or philosophical works, defenses of their policies, effusive poems of praise, and larger-than-life individual and family portraits, rulers – and also wealthy churchmen and nobles – provided pensions in cash, positions as tutors, offi ces at court or ecclesiastical benefi ces. Along with this traditional system of patronage, however, new social and cultural institutions developed through which ideas were exchanged, and writers, artists, and thinkers were supported. Some of the institutions were formal, including scientifi c and literary societies, journals and newspapers, and clubs or lodges that one paid to join. Many of them were more informal, including salons, coffeehouses, booksellers’ shops, and taverns. These new institutions operated outside the traditional intellectual centers of courts, churches, and universities, and created what the German philosopher and historian Jürgen Habermas called the “public sphere,” which provided both an audience for new ideas and a place where those ideas were often germinated. They were the places where the business of the Enlightenment was conducted.