Science as a Candle in the Dark


In today’s episode, I’d like to talk about Carl Sagan, and his book, The Demon Haunted World: Science as a Candle in the Dark.

I’ve been thinking a lot lately about Carl Sagan, and this book in particular, because I’ve always admired how it inspires clear thinking when chaos seems to reign supreme.

Sagan was a brilliant popularizer of science. An expert astronomer and cosmologist who also produced wildly popular science programs for the rest of us, like Pale Blue Dot and Cosmos. The reason Sagan is famous is not because of what he discovered as a scientist, but rather because of how he inspired the public to appreciate science. He, more than anyone, taught that science wasn’t just about facts; it’s about the wonder of nature. And in this book, he appeals to that idea to help highlight necessity of scientific thinking in modern society.

Wonder is often forgotten as an essential ingredient to science, but curiosity is what compels us investigate the world in the first place, and wonder at how it works provides the sense of meaning. We humans like to be dazzled, to be awe struck. Awe and even fear are common currencies of social import. Good story tellers are popular for this reason. We need equal helpings of information and emotion to be satisfied.

Early on in The Demon Haunted World, Sagan share’s an illustrative anecdote. He’s sharing a cab with another guy, who’s really excited to meet a world-famous scientist and seizes the opportunity to ask Sagan all sorts of questions about aliens, Atlantis, and giant krakens of the deep—the man was steeped in a whole world of conspiracy theories and magical myths. Sagan kept replying that the evidence for such fancies didn’t exist, and simpler explanations abounded anyways. This was clearly disappointing. “As we drove through the rain, I could see him getting glummer and glummer. I was dismissing not just some errant doctrine, but a precious facet of his inner life.”

Most of us are inclined to believe in magic, and not just as children. Judging by our history, magical thinking is natural. Might even be a facet of our evolutionary success. One example Sagan provides concerns primate pattern recognition. Humans, he points out, are gregarious. Parents smile at their children, children smile back, and a bond critical survival is forged. “As soon as an infant can see, it recognizes faces, and we now know that this skill is hardwired in our brains. Those infants who, a million years ago, were unable to recognize a face smiled back less, were less likely to win the hearts of their parents, and less likely to prosper. These days, nearly every infant is quick to identify a human face and to respond with a goony grin. As an inadvertent side effect, the pattern-recognition machinery in our brains is so efficient in extracting a face from a clutter of other detail that we sometimes see faces where there are none… The man in the moon is one result…Sometimes it’s changing patterns in the clouds… When the face is of a religious personage…believers tend quickly to deduce the hand of God.”

We’re not innately skeptical of supernatural explanations. We’re born with a bias toward the marvelous. The magician’s illusion is always more fun than his explanation of the trick.

Now, scientists are well aware of all this, and their common retort is that, as Sagan says, “there’s so much in science that’s equally exciting, more mysterious, a greater intellectual challenge—as well as being a lot closer to the truth.” Eh… it’s hard to make that stick, emotionally. It’s far easier, far more satisfying, and far more in line with how our brains have evolved to fill in the dark spaces of our world with supernatural forces than to simply withhold speculation.

And why does it often seem like the more we do understand something scientifically, the less enchanting it becomes? Why is the illusion more fun than the explanation? This is the real problem…not only is it often easier to believe in nonsense, it’s often more satisfying. This is why scientific thinking has always had the deck stacked against it.

Maybe a better analogy is that practicing scientific thinking is like staying physically fit—the benefits may be clear, but you have to work hard to achieve them. The natural tendency, our natural appetite, is to be lazy and fat and eat whatever we want. It takes no effort to be out of shape. It’s the same with believing in nonsense; it’s easy, it’s natural, it’s the default state of human psychology. Thinking scientifically, skeptically, rigorously, that’s what takes discipline. That’s what hard. But with practice, it too gets easier, just like it gets easier to run a mile as your train.

One problem, of course, is that indulging in nonsense can be far more dangerous than indulging in laziness or junk food. In the face of modern challenges like tribalism, global pandemics, nuclear proliferation, and global warming, scientific illiteracy can be fatal not only to individuals but to our civilization.

How has the tension between science and myth, between facts and faith, play out in the modern world? One common thread is what has been known as the “God of the Gaps” phenomenon. Our map of knowledge has clearly been expanding rapidly over the past few centuries. Within 400 years we’ve gone from believing that it’s good to burn women alive for committing unverified deeds of the devil to understanding evolutionary psychology and network effects conducive to mobs. With the tools of science, we’re whittling away at the universe of ignorance all the time, but plenty of gaps in our knowledge remain, and here be dragons.

The dark places on our map of knowledge remain a refuge for divine explanations. Things yet beyond our comprehension are things yet attributed to God. We used to think that plagues were a form of God’s wrath, divine punishment for our sins, a God of the Gap in our knowledge of disease. Then we invented microscopes and that gap in our knowledge closed as we learned that microorganisms are the agents of disease. The more we learn, the less we attribute to divine intervention. When it comes to disease, this is obviously a good thing in many ways. For example, for a million years, life expectancy among hominids was between 20 and 30 years of age. Through the medieval era a thousand years ago, it still hovered around 30. It only reached 40 in the West around 150 years ago. It wasn’t this low for so long because healthy adults aged and died faster. It wasn’t like a 30 year old a thousand years ago resembled a 70 year old of today. No, if you reached middle age back then, you had a reasonable chance of living into your 60s, 70s, and even 80s. The real reason life expectancy was so low for so long is because so many children died of disease that it dragged the average down. It was only after the emergence of the germ theory of disease and associated medical interventions that the outlying cluster of child mortality could be removed and the average life expectancy could rise closer to the uninterrupted span of human longevity. Again, these examples of scientific progress are obviously boons to human prosperity. Good riddance to these gaps where gods once terrified us. As Sagan wrote, “Advances in medicine and agriculture have saved vastly more lives than have been lost in all the wars in history.”

But, advances in science that help save children is a softball—that’s an easy one to get behind. The god of that particular gap in knowledge was a monster. The harder cases are where gaps are filled with more enchanting gods, gods who make the unsolved mysteries seem magical, gods who make us feel special. Sagan, like many other evangelists of science, is confident that “it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.” He argues that this attitude will not only better ensure our long-term survival, but that it also deepens our appreciation for the grandeur of nature and makes us feel more connected to the history of all living things. In any case, Sagan acknowledges, there’s no going back: “Like it or not, we are stuck with science. We had better make the best of it.”

No matter how badly we may want to believe in certain myths, once we know better, we can’t will ourselves back into ignorance. This is a heavy burden, Sagan admits. Friedrich Nietzsche was spot on. In this sense, modernity is hard.

The real reason that science is so hard is because it is not simply a body of knowledge; it’s a way of thinking. We have more knowledge at our fingertips today than we’ve ever had – anyone can google practically any fact and recite what they read. But this revolution in the accessibility of knowledge is not, as it turns out, accompanied by a revolution in scientific thinking. Just the opposite. Pseudoscience is spreading like a weed. Superstition, conspiracy theories, quack medicine, and tribalism are overtaking reasoned skepticism everywhere, from Twitter and the media to university curriculums. As Sagan predicted a quarter century ago, the information economy in particular prioritizes the provocative over the true. “We’ve arranged a global civilization… [that] profoundly depends on science and technology. We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster.”

A primary reason for Sagan’s concern is that we live in a democracy. Each one of us has the historically exceptional power to vote. But, that power comes with the responsibility to cultivate clear thinking. The invention of public education by democratic societies reflects this. The scientific way of thinking, Sagan emphasizes, is an essential tool of democracy especially in an age of change because, he writes, “science leads us to let the facts in, even when they don’t conform to our preconceptions… it urges on us a delicate balance between… openness to new ideas and established wisdom… every time we exercise self-criticism, every time we test our ideas against the outside world, we are doing science.”

Humans tend to crave certainty. Historically, we’re uncomfortable with what is often the simplest answer to our biggest questions: we don’t know. What the history of science has demonstrated in a way that no other system of knowledge ever has, is that through a framework of reasoned skepticism involving calculation, experiment, logic, peer review, and simple rational conversation, we can, at least, successively improve our understanding of things, even though we will never ever understand everything perfectly. In most religious traditions, that surrender to the horizon of ignorance is accomplished through faith. Faith that God is not just filling in the gaps of understanding, but orchestrating the entire ensemble of existence, whether we think we understand it or not. That right there where much of the heavy lifting of religion is leveraged. Faith satiates humanity’s cravings for certainty in a way that science never could. And as a product of human minds, faith-based answers to our biggest questions are designed to satisfy our minds’ musings. Science loses here, too. As Sagan writes, “Because science carries us toward an understanding how the world is, rather than how we would wish it to be, its findings may not in all cases be immediately comprehensible or satisfying.” The physicist Max Tegmark, who teaches at MIT, goes even further. He points out that would be downright surprising if the building blocks of reality aligned with our common sense intuitions, because those intuitions have evolved to help us survive in a very narrow band of time and space and energy. “Whatever the ultimate nature of reality is,” Tegmark recently said, “it should seem really weird and counterintuitive to us…[For example], we’ve studied what happens when things go much faster than our ancestors could imagine, near the speed of light: time slows down. Whoa!…You look at what happens when things are really, really large and you get black holes, which were considered so weird… And then you look at what happens when you make things really small—so that our ancestors couldn’t see them. And you find that elementary particles can be in several places at once? Extremely counterintuitive… And the list goes on…” Not only that, but science can be weird in a way that often turns out not to be very satisfying to creatures like ourselves, whose cultural evolution favors stories animated by anthropogenic protagonists of good and evil. Quarks mean little in this context.

Science also violates our affinity for the sacred. In principle, nothing is sacred in science. No matter how popular any particular scientific idea may be, you must abandon it whenever another one comes along that better fits the data. As Sagan writes, “in science, we give our highest rewards to those who convincingly disprove established beliefs.” That’s a very big ask. Modern minds are forced to adapt to so much change brought on by technological disruption that we might be forgiven for clinging to the sacred ground of our traditional beliefs all the more stridently. Science assaults this instinct with the brute force of novel data all the time. Our understanding of how the world works changes fundamentally by the century. Whatever happened to ancient legends? What ever happened to ancestral stories that guided our understanding unchanged for hundreds of generations at a stretch? Those were the good old days… well, aside from life being relatively nasty, brutish, and short.

Scientists assert that facts are superior to fantasy. But, how helpful is that assertion when we are emotionally invested in our beliefs? Much of the time, we simply cherry pick whatever facts fit our beliefs. We listen to whatever news shows, join whatever Facebook groups, and follow whatever Twitter accounts reinforce how we already feel. The brilliant social psychologist Jonathan Haidt published a best-selling book about this in 2012 called The Righteous Mind, where he demonstrated how our brains tend to employ rational thought not to form our beliefs but to justify the ones we already have. Scientists are vulnerable to this just as much as the rest of us.

Toward the end of the book, Sagan acknowledges what is perhaps the most challenging aspect of scientific thinking: “If it is to be applied consistently, science imposes, in exchange for its manifold gifts, a certain onerous burden: we are enjoined, no matter how uncomfortable it might be, to consider ourselves…scientifically…” When the lens of reason becomes a mirror, things get personal. Our culture, our identity, our sense of what the hell is really going on here are the most important facets of our lives, and they are nearly impossible to evaluate without sustained, rigorous practice in rational inquiry. And even then, it’s really hard. It’s hard because the truth is often not as comforting, or as self-centered, or as intuitive, or as fantastic, or as redeeming as might want. Millions of people remain appalled by Darwin’s discovery that we have evolved from prehistoric apes. Millions of people were appalled by Galileo’s confirmation that the Earth was not the center of the universe. In the centuries to come, our descendants will undoubtedly be appalled by discoveries we can’t currently imagine. We are not dispassionate observers. The nature of reality, it turns out, really matters to us. And, the tendency is for people to want reality to be a certain way prior to knowing how it actually is. We do not simply hold our beliefs. We cherish them. Postmodernists and populists alike leverage this to poison the modern concept of truth. In their worldview, what is real is adjudicated not by the weight of evidence but by the weight of feeling and power. Postmodernism and populism appeal to the gut and the heart. Modernism appeals to the mind. In a battle of ideas, that’s never been a fair fight.

So, in spite of all the strikes against it, how does scientific thinking prevail? Perhaps it prevails best simply through good leadership, at every level, from our parents, to our teachers, to senior editors and executives in media companies, to the President of the United States. Leaders who are more focused on long term prosperity than short term profits. Leaders who exemplify strength in reason instead of strength in numbers. As Thomas Jefferson wrote, “If a nation expects to be both ignorant and free in a state of civilization, it expects what never was and never will be.”

Carl Sagan was not just a popularizer of science. He helped us understand the symbiosis between scientific thinking and freedom. Freedom, he wrote, “is a prerequisite for continuing the delicate experiment of science—which is one reason the Soviet Union could not remain a totalitarian state and be technologically competitive. At the same time, science—[the] delicate mix of openness and skepticism, and its encouragement of diversity and debate—is a prerequisite for continuing the delicate experiment of freedom in an industrial and highly technological society.” If we can’t think critically for ourselves, Sagan insisted, then we’re just putty in the hands of those in power, and stooges easily riled up by the mob.

Ultimately, scientific thinking prevails out of necessity. We can either allow ourselves to indulge in ignorance and enable those in power to control us, or we can educate ourselves to think scientifically and ensure that those in power work for us.

I’m Brad Harris. So long.

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