Enlightenment Now: The Case for Reason, Science, Humanism, and Progress

It was reason that led most of the Enlightenment thinkers to repudiate a belief in an anthropomorphic God who took an interest in human affairs.⁶ The application of reason revealed that reports of miracles were dubious, that the authors of holy books were all too human, that natural events unfolded with no regard to human welfare, and that different cultures believed in mutually incompatible deities, none of them less likely than the others to be products of the imagination. (As Montesquieu wrote, “If triangles had a god they would give him three sides.”) For all that, not all of the Enlightenment thinkers were atheists. Some were deists (as opposed to theists): they thought that God set the universe in motion and then stepped back, allowing it to unfold according to the laws of nature. Others were pantheists, who used “God” as a synonym for the laws of nature. But few appealed to the law-giving, miracle-conjuring, son-begetting God of scripture.

Many writers today confuse the Enlightenment endorsement of reason with the implausible claim that humans are perfectly rational agents. Nothing could be further from historical reality. Thinkers such as Kant, Baruch Spinoza, Thomas Hobbes, David Hume, and Adam Smith were inquisitive psychologists and all too aware of our irrational passions and foibles. They insisted that it was only by calling out the common sources of folly that we could hope to overcome them. The deliberate application of reason was necessary precisely because our common habits of thought are not particularly reasonable.

That leads to the second ideal, science, the refining of reason to understand the world. The Scientific Revolution was revolutionary in a way that is hard to appreciate today, now that its discoveries have become second nature to most of us. The historian David Wootton reminds us of the understanding of an educated Englishman on the eve of the Revolution in 1600:

He believes witches can summon up storms that sink ships at sea. . . . He believes in werewolves, although there happen not to be any in England—he knows they are to be found in Belgium. . . . He believes Circe really did turn Odysseus’s crew into pigs. He believes mice are spontaneously generated in piles of straw. He believes in contemporary magicians. . . . He has seen a unicorn’s horn, but not a unicorn.

He believes that a murdered body will bleed in the presence of the murderer. He believes that there is an ointment which, if rubbed on a dagger which has caused a wound, will cure the wound. He believes that the shape, colour and texture of a plant can be a clue to how it will work as a medicine because God designed nature to be interpreted by mankind. He believes that it is possible to turn base metal into gold, although he doubts that anyone knows how to do it. He believes that nature abhors a vacuum. He believes the rainbow is a sign from God and that comets portend evil. He believes that dreams predict the future, if we know how to interpret them. He believes, of course, that the earth stands still and the sun and stars turn around the earth once every twenty-four hours.⁷

A century and a third later, an educated descendant of this Englishman would believe none of these things. It was an escape not just from ignorance but from terror. The sociologist Robert Scott notes that in the Middle Ages “the belief that an external force controlled daily life contributed to a kind of collective paranoia”:

Rainstorms, thunder, lightning, wind gusts, solar or lunar eclipses, cold snaps, heat waves, dry spells, and earthquakes alike were considered signs and signals of God’s displeasure. As a result, the “hobgoblins of fear” inhabited every realm of life. The sea became a satanic realm, and forests were populated with beasts of prey, ogres, witches, demons, and very real thieves and cutthroats. . . . After dark, too, the world was filled with omens portending dangers of every sort: comets, meteors, shooting stars, lunar eclipses, the howls of wild animals.⁸

To the Enlightenment thinkers the escape from ignorance and superstition showed how mistaken our conventional wisdom could be, and how the methods of science—skepticism, fallibilism, open debate, and empirical testing—are a paradigm of how to achieve reliable knowledge.