The Enlightenment of the 18th century was not only a crucial epoch, a sea-change in human history - it was also a vast moral, scientific and political movement. Intellectuals across Europe and the New World linked up in networks of friendship, projects and debates, and began to free themselves of the authority of the church and find a sense of their own vocation, a calling to rethink the world in secular terms. This volume shows how the leading thinkers of the movement believed that by means of scientific endeavour the essential order of nature could be systematically explained, its processes could be mastered and all of its secrets revealed. The book focuses on three of the giants of the Enlightenment - Voltaire, Diderot, Adam Smith, Samuel Johnson, Immanuel Kant, Benjamin Franklin, and Thomas Jeffeson.