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

Reflecting on liberal ideals in 1960, not long after they had withstood their greatest trial, the economist Friedrich Hayek observed, “If old truths are to retain their hold on men’s minds, they must be restated in the language and concepts of successive generations” (inadvertently proving his point with the expression men’s minds). “What at one time are their most effective expressions gradually become so worn with use that they cease to carry a definite meaning. The underlying ideas may be as valid as ever, but the words, even when they refer to problems that are still with us, no longer convey the same conviction.”²

This book is my attempt to restate the ideals of the Enlightenment in the language and concepts of the 21st century. I will first lay out a framework for understanding the human condition informed by modern science—who we are, where we came from, what our challenges are, and how we can meet them. The bulk of the book is devoted to defending those ideals in a distinctively 21st-century way: with data. This evidence-based take on the Enlightenment project reveals that it was not a naïve hope. The Enlightenment has worked—perhaps the greatest story seldom told. And because this triumph is so unsung, the underlying ideals of reason, science, and humanism are unappreciated as well. Far from being an insipid consensus, these ideals are treated by today’s intellectuals with indifference, skepticism, and sometimes contempt. When properly appreciated, I will suggest, the ideals of the Enlightenment are in fact stirring, inspiring, noble—a reason to live.

CHAPTER 1DARE TO UNDERSTAND!

What is enlightenment? In a 1784 essay with that question as its title, Immanuel Kant answered that it consists of “humankind’s emergence from its self-incurred immaturity,” its “lazy and cowardly” submission to the “dogmas and formulas” of religious or political authority.¹ Enlightenment’s motto, he proclaimed, is “Dare to understand!” and its foundational demand is freedom of thought and speech. “One age cannot conclude a pact that would prevent succeeding ages from extending their insights, increasing their knowledge, and purging their errors. That would be a crime against human nature, whose proper destiny lies precisely in such progress.”²

A 21st-century statement of the same idea may be found in the physicist David Deutsch’s defense of enlightenment, The Beginning of Infinity. Deutsch argues that if we dare to understand, progress is possible in all fields, scientific, political, and moral:

Optimism (in the sense that I have advocated) is the theory that all failures—all evils—are due to insufficient knowledge. . . . Problems are inevitable, because our knowledge will always be infinitely far from complete. Some problems are hard, but it is a mistake to confuse hard problems with problems unlikely to be solved. Problems are soluble, and each particular evil is a problem that can be solved. An optimistic civilization is open and not afraid to innovate, and is based on traditions of criticism. Its institutions keep improving, and the most important knowledge that they embody is knowledge of how to detect and eliminate errors.³

What is the Enlightenment?⁴ There is no official answer, because the era named by Kant’s essay was never demarcated by opening and closing ceremonies like the Olympics, nor are its tenets stipulated in an oath or creed. The Enlightenment is conventionally placed in the last two-thirds of the 18th century, though it flowed out of the Scientific Revolution and the Age of Reason in the 17th century and spilled into the heyday of classical liberalism of the first half of the 19th. Provoked by challenges to conventional wisdom from science and exploration, mindful of the bloodshed of recent wars of religion, and abetted by the easy movement of ideas and people, the thinkers of the Enlightenment sought a new understanding of the human condition. The era was a cornucopia of ideas, some of them contradictory, but four themes tie them together: reason, science, humanism, and progress.

Foremost is reason. Reason is nonnegotiable. As soon as you show up to discuss the question of what we should live for (or any other question), as long as you insist that your answers, whatever they are, are reasonable or justified or true and that therefore other people ought to believe them too, then you have committed yourself to reason, and to holding your beliefs accountable to objective standards.⁵ If there’s anything the Enlightenment thinkers had in common, it was an insistence that we energetically apply the standard of reason to understanding our world, and not fall back on generators of delusion like faith, dogma, revelation, authority, charisma, mysticism, divination, visions, gut feelings, or the hermeneutic parsing of sacred texts.