III.

Reason and Progress

Of the basic assumptions and beliefs common to philosophers and intellectuals of this period, perhaps the most important was an abiding faith in the power of human reason. The age was enormously impressed by the discovery by Isaac Newton of universal gravitation. If humanity could so unlock the laws of the universe, God’s own laws, why could it not also discover the laws underlying all of nature and society? This belief was summed up by Alexander Pope: “Nature and nature’s laws lay hid in night, / God said, ‘Let Newton be,’ and all was light.”

Enlightenment thinkers placed a great premium on the discovery of truth through the observation of nature, rather than through the study of authoritative sources, such as Aristotle and the Bible. If the centuries-old medieval view of the physical world had been so decisively overthrown by reason, then 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.

During the Enlightenment, people came to assume that through a judicious use of reason, an unending progress would be possible—progress in knowledge, in technical achievement, and even in moral values. Following the philosophy of Locke, the 18th-century writers believed that knowledge is not innate, but comes only from experience and observation guided by reason. Through proper education, humanity itself could be altered, its nature changed for the better.

Although they saw the church—especially the Roman Catholic Church—as the principal force that had enslaved the human mind in the past, most Enlightenment thinkers did not renounce religion altogether. They opted rather for a form of Deism, accepting the existence of God and of a hereafter, but rejecting the intricacies of Christian theology. Human aspirations, they believed, should not be centered on the next life, but rather on the means of improving this life. Worldly happiness was placed before religious salvation. Nothing was attacked with more intensity and ferocity than the church, with all its wealth, political power, and suppression of the free exercise of reason.