II.

Early Influences

The precursors of the Enlightenment can be traced to the 17th century and earlier. They include the philosophical rationalists René Descartes, Gottfried Leibniz, and Baruch Spinoza, the political philosophers Thomas Hobbes and John Locke, and sceptical thinkers in France such as Pierre Bayle. Equally important was the self-confidence engendered by new discoveries in science—by Nicolaus Copernicus and Galileo, for example—as well as the cultural relativism encouraged by the exploration of the non-European world.

A fundamental and widely shared belief of the period was the unshakeable faith in the power of human reason. Thinkers of the age were enormously impressed by the discovery of universal gravitation by Isaac Newton. This is summed up by the Alexander Pope quote: “Nature and nature’s laws lay hid in night, / God said, ‘Let Newton be’, and all was light.” The laws governing the rest of nature, the human mind, and society could, it seemed, soon be discovered by applying Newton’s method. If the centuries-old medieval view of the physical world had been so decisively overthrown by reason, the antiquity of an idea, or indeed of a law, a privilege, or a form of government, could no longer be seen as a guarantee of its worth. People came to assume that by judicious use of reason, an unending progress would be possible—progress in knowledge, technology, prosperity, and even in moral values.