In this sublime short excerpt from his recently remasteredCosmos series, Sagan does just that as he explains how stars are born, live, die, and give us life:
The events in one star can influence a world halfway across the galaxy and a billion years in the future… But from a planet orbiting a star in a distant globular cluster, a still more glorious dawn awaits — not a sunrise, but a galaxy-rise; a morning filled with four hundred billion suns — the rising of the Milky Way… From such a world… it would be clear, as it is beginning to be clear in our world, that we are made by the atoms and the stars, that our matter and our form are determined by the cosmos by which we are a part.
The importance of playing the long game in life, be it extraterrestrial or earthly.
By Maria Popova
Astronomer Jill Tarter grew up taking apart and reassembling her father’s radios. She is the Bernard M. Oliver Chair for SETI Research — California’s institute of Search for Extraterrestrial Intelligence — and the inspiration for Jodie Foster’s character in the iconic 1997 film Contact, adapted from Carl Sagan’s novel of the same title. The recipient of two public service medals from NASA and the TED Prize, among ample other accolades, Tarter has spent nearly forty years searching the cosmos for alien life and advocating for the importance of that inquiry.
In this short video from NOVA, Tarter recounts how Sagan and Ann Druyan contacted her about the novel and explores the broader question of why the search for extraterrestrial life matters — and matters enormously:
I don’t get out of bed every morning thinking, “Will I find extraterrestrial intelligence today?” But I do think every day, “How can I improve the search?” Fifty years of silence doesn’t mean SETI is a failure; it means we’re just getting started. We may not succeed tomorrow or next year or next decade or even next century, but a critical part of our job is passing on what we’ve learned to the future generations of cosmic scientists.
What a wonderful disposition toward life, extraterrestrial or earthly — to think how much more we could achieve and with what greater ease we could live if we only applied this to our everyday lives, from the search for love to the conquest of a project.
“We [are] a species endowed with hope and perseverance, at least a little intelligence, substantial generosity and a palpable zest to make contact with the cosmos.”
By Maria Popova
In 1939, just before his fifth birthday, Carl Sagan visited the New York World’s Fair, where he marveled at the Time Capsule evincing the fair’s confidence in the future — a hermetically sealed chamber, filled with newspapers, books and artifacts from that year, buried in Flushing Meadows to be revisited in some far-off future era by a future culture very different from and curious about the present. “There was something graceful and very human in the gesture, hands across the centuries, an embrace of our descendants and our posterity,” Sagan writes in Murmurs of Earth: The Voyager Interstellar Record (public library) — the fascinating chronicle of how, in the early fall of 1977, he and a team of collaborators imbued a similar time capsule with even greater hopefulness of cosmic proportions and sent it into space aboard the Voyager spacecraft as humanity’s symbolic embrace of other civilizations. On it, they set out to explain our planet and our civilization to another in 117 pictures, greetings in 54 different languages and one from humpback whales, and a representative selection of “the sounds of Earth,” ranging from an avalanche to an elephant’s trumpet to a kiss, as well as nearly 90 minutes of some of the world’s greatest music.
Sagan, in his characteristic eloquence, writes of the motivation, offering a poetic, humbling, and timelier than ever reminder of just how misplaced our existential arrogance is:
The coming of the space age has brought with it an interest in communication over time intervals far longer than any [of our predecessors] could have imagined, as well as the means to send messages to the distant future. We have gradually realized that we humans are only a few million years old on a planet a thousand times older. Our modern technical civilization is one ten-thousandth as old as mankind. What we know well has lasted no longer than the blink of an eyelash in the enterprise of cosmic time. Our epoch is not the first or the best. Events are occurring at a breathless pace and no one knows what tomorrow will bring — whether our present civilization will survive the perils that face us and be transformed, or whether in the next century or two we will destroy our technological society. But in either case it will not be the end of the human species.
There will be other people and other civilizations, and they will be different from us. Our civilization is the product of a particular path our ancestors have followed among the vagaries of historical alternatives. Had events of the distant past taken a slightly different turn, our surroundings and thought processes, what we find natural and hold dear, might be very different. Despite our every sense that things should of course be the way that they are, the details of our particular civilization are extraordinarily unlikely, and it is easy to imagine a set of historical events which would have led to a rather different civilization… This lack of historical determinism in the details of a civilization means that those details are of extraordinary value, not just to professional historians but to all who wish to understand the nature of culture. I think it is this respect for the integuments of a civilization that, above all other reasons, make us sympathetic to the enterprise of time capsuling.
As for the obvious question of how arrogant it seems to assume that if other civilizations exist — something most scientists agree has a high likelihood given the vastness of the cosmos — they would be similar enough to us to be able to interpret our messages, Sagan offers some optimistic rationale:
There is an argument — perhaps it is only a hope — that we might be able to communicate with representatives of such exotic civilizations, because they, like we, must come to grips with the same laws of physics and chemistry and astronomy. The composition of a star and its spectral properties are not fundamental impositions that scientists have made on nature, but rather the other way around. There is an external reality that we ignore at our peril, and indeed much of the evolution of the human species can be described as an increasing concordance between the images within our brains and the reality in the external world. Thus, whatever the differences in starting points, there must come to be a gradual convergence in intellectual content and discipline between diverse planetary species.
And so the idea of the Golden Record was born — a piece of communication that captures the essence of our species and our civilization, and transmits it using the era’s best recording technology and spacecraft to possible others out in the unknown. Sagan’s first thought was to improve on the plaques which accompanied NASA’s Pioneer spacecraft, mankind’s first interstellar probes launched in the early 1970s, which contained some scientific information in textual form and “a sketch of two representatives of the human species greeting the cosmos with hope.” To that, Sagan wanted to add some information from molecular biology to represent what we are made of, and some other materials. He gathered together a small group of scientific consultants, each of whom would advise on the contents of the Voyager message. Some of the opinions were wonderfully poetic — B.M. Oliver, vice-president for research and development at Hewlett-Packard, captured the heart of the project beautifully:
There is only an infinitesimal chance that the plaque will ever be seen by a single extraterrestrial, but it will certainly be seen by billions of terrestrials. Its real function, therefore, is to appeal to and expand the human spirit,and to make contact with extraterrestrial intelligence a welcome expectation of mankind.
Meanwhile, beloved sci-fi author Arthur C. Clarke — who was highly invested in space exploration and had participated in a historic conversation on the subject with Sagan some years earlier — phoned in from Sri Lanka and recommended that the plaque contain the following message, intended as a statement of hope that our civilization would go on long enough for the message to be read:
Please leave me alone; let me go on to the stars.
As more suggestions rolled in, it became clear that the capsule should contain more than scientific information — it should include, rather, a full-spectrum view of humanity, including our artistic footprint. But that would require a recording technology for encoding text, image, and audio, as a visual plaque would no longer suffice. Around the same time, Sagan realized that 1977 was the 100th anniversary of Thomas Edison’s invention of the phonograph. 1977 was also the year when Peter Goldmark, inventor of the long-playing record, perished in a tragic car-crash. Thanks to this bittersweet symmetry and the suggestions of his technological advisors, Sagan decided to encode humanity’s message on a record. And thus the Golden Record was born. He considers the less obvious but no less important reason for this choice, one that honors the notion that emotion is at the heart of human creativity and the intellect alone is never enough:
I was delighted with the suggestion of sending a record for a different reason: we could send music. Our previous messages had contained information about what we perceive and how we think. But there is much more to human beings than perceiving and thinking. We are feeling creatures. However, our emotional life is more difficult to communicate, particularly to beings of very different biological make-up. Music, it seemed to me, was at least a creditable attempt to convey human emotions. Perhaps a sufficiently advanced civilization would have made an inventory of the music of species on many planets, and by comparing our music with such a library, might be able to deduce a great deal about us.
There was another reason for music, too: Because of music’s highly mathematical quality and the fact that scientists believe mathematical relationships hold up for all cultures, philosophies, biologies, and planets, this universality would suggest, as Sagan puts it, “that much more than our emotions are conveyed by the musical offerings on the Voyager record.”
Once the idea was conceived, the first set of challenges were technical. An ordinary vinyl record is made by pressing the vinyl from a mold made of a copper and nickel positive material called “mother.” A vinyl record would be vulnerable to erosion in space, but the “mother” would be considerably less so. But because nickel is ferromagnetic, it would interfere with the fine-tuned magnetic field detection experiments of the Voyager. So Sagan decided that a copper mother would be needed and reached out to the vice-president of RCA Records to help with the technical development of the record.
But another technical challenge was that, limited by the compression technology of the time, they could only fit around 27 minutes of playing time on each side of a record to be played at a standard 33 1/3 revolutions per minute. One side would be musical, and the other graphical, containing pictures. That immediately put enormous pressure on them as to the selection of the music, given the space afforded was “barely enough for two movements of a single symphony.”
Once again, Sagan enlisted a team of advisors, including various musicologists, conductors, musicians, scholars, and the writer Ann Druyan, with whom he’d go on to fall in love over the course of the project and spend the rest of his life. Among them was the famed 20th-century folk music field collector Alan Lomax, who had spent decades building a classified library of virtually all recorded musical styles in the world. He became a major influence that shaped the Golden Record’s truly global sound. Sagan recalls one of his first encounters with Lomax:
When Lomax first played Valya Balkanska’s soaring Bulgarian shepherdess’ aria for Ann, she was moved to spontaneous dance. “Do you hear that, honey?” he drawled, grinning and leaning forward. “That’s Europe. That’s the first people who had enough to eat.”
We are particularly grateful to him for his help in broadening our transcultural musical perspectives, as well as in substantially enhancing the beauty of the Voyager’s musical offerings.
Eventually, Sagan and his collaborators brainstormed a way to increase the storage capacity: They had a record designed for 16 1/3 revolutions per minute, which would decrease the fidelity slightly, but would more than triple the length to a total of nearly 90 minutes, which Sagan felt would let them “at least approach doing some justice to the range, depth and magic of the world’s music.” But by the time the technical challenge had been solved, the launch date of the Voyager had drawn alarmingly near, which made the decision about what to include all the more overwhelming. Sagan offers a taste of just how dizzying that process was:
There is obviously no best answer about what music to send to the stars; there are as many answers as there are people who attempt to make such a decision.
There were long debates on Gregorian chants, Charles Ives and Bob Dylan (would the music stand if the words were incomprehensible?); whether we should include more than one Bulgarian or Peruvian composition; an Apache lullaby (and the role of Apaches among Native Americans); the definition of Near Eastern music; whether to include music performed by alleged Nazi sympathizers; whether to include music performed by Pablo Casals, whose spirit we very much admired but whose records were of poor quality; which version of the Second Brandenburg Concerto…
They even brushed up against the absurdities of copyright:
We wanted to send “Here Comes the Sun” by the Beatles, and all four Beatles gave their approval. But the Beatles did not own the copyright, and the legal status of the piece seemed too murky to risk.
And yet beneath all the madness lay a heartening allegory for the spirit of the project, best captured in this anecdote by Ann Druyan:
Robert Brown [the executive director of the Center for World Music in Berkeley] had placed Surshri Kesar Bai Kerkar’s “Jaat Kahan Ho” at the top of his list of world music for outer space. It was an old recording that had recently gone out of print. After hunting through a score of record stores without any success, I phoned Brown and asked him to suggest an alternative raga.
“Well, what happens if we can’t find a copy of this one in time to get it on the record?” I pleaded. We had three more days in which to complete the repertoire. I was terribly worried that Indian music, one of the world’s most intricate and fascinating traditions, might not be represented.
“Keep looking,” he told me.
When I phoned him the following day after a series of very unrewarding conversations with librarians and cultural attachés, I was desperate.
“I promise I’ll keep looking for ‘Jaat Kahan Ho,’ but you’ve simply got to give me the name of a piece that we can fall back on. What’s the next best thing?”
“There’s nothing close,” he insisted. “Keep looking.” The other ethnomusicologists we had been consulting told me to trust him. I started phoning Indian restaurants.
There’s an appliance store on Lexington Avenue in the Twenties in New York City that is owned by an Indian family. Under a card table with a madras cloth thrown over it sits a dusty brown carton with three unopened copies of ‘Jaat Kahan Ho.'” Why I want to buy all three occasions a great deal of animated speculation on the part of the owners. I fly out of the shop and race uptown to listen to it.
It’s a thrilling piece of music. I phone Brown and find myself saying thank you over and over.
Nearly every challenge was resolved in a similarly heartening way, but nowhere more so than when it came to the eternal see-saw of greed and altruism. When RCA realized that only one song from the final selections was recorded by RCA Victor, they refused to be of further help with producing the record. Sagan and his team had chosen the music without any reference to label or manufacturer, but realized many of the selections came from Columbia Records, so they reached out to the label for help. After the greedy RCA letdown, a much-needed restoration of faith in the human spirit presented itself when the president of Columbia enthusiastically backed the project. Sagan writes with equal parts humor and humility:
It is not as easy as you might think to attract the attention of the president of a major competitive commercial record company on short notice for any enterprise, much less for volunteering corporate resources to send a record to the stars where, even if there are many potential listeners, no impact on corporate profits is likely to be made, at least in the near future. But, eventually, CBS Records, entirely as a public service, secured all the releases, mixed the music, greetings and sounds, and cut the wax masters from which the metal mothers are made. Worldwide releases were obtained in an unprecedentedly brief time. Since there was no way for CBS Records to increase corporate earnings from this project, their cooperation, although in some quarters reluctant, was on the whole truly remarkable.
The next challenge was of the bureaucratic kind. In addition to the music, Sagan and his team had decided to include a simple greeting in spoken human language. To keep it globally representative, they decided to have a “Hello” in a few dozen languages and figured approaching the United Nations would be the best way to secure the greetings. Sagan had just given an address on space exploration at the UN General Assembly the previous year and had kept in touch with some members of the UN Outer Space Committee, so he used the connection to ask for the greetings. But he was told that the Committee couldn’t itself initiate any “action,” which was only possible for the national delegations. The American Mission to the United Nations was in charge of those, but it would only act if instructed by the State Department, which would only act if so requested by NASA. The Catch-22 was that at that point, NASA hadn’t even formally agreed to include the record on the Voyager, and the State Department needed firm assurance that UN greetings would be included in order to initiate the “action.”
This, in other words, is what happens when a government is a string of middle-managers and bureaucrats whom humanity is supposed to trust for representation.
So Sagan proposed a solution: A recording studio would be set up for a couple of days at the UN Headquarters in New York, and a delegate from each member nation would drop in to record the coveted “Hello” in his or her language. “Her” turned out to be another point of challenge, and one tragically similar today: Sagan wanted an equal number of male and female voices, in order to represent the gender balance of Earth, but was quickly informed that “virtually all the chiefs of delegations were male, and it was unlikely that they would delegate the privilege of saying ‘Hello’ to the stars to anyone else.” (The male ego, indeed, is of cosmic proportions.) Other concerns were raised about what happens if a delegate is not in New York and further bureaucracy ensued. Sagan recounts with amused exasperation:
What is more, the Outer Space committee would have to vote on whether to say “Hello,” and its next meeting was to be in Europe in late June. I explained that even if greetings from the Outer Space Committee were desirable, the launch schedule of Voyager would not permit such a dilatory pace. Could we not, I was then seriously queried, postpone the Voyager launch?
Eventually, they plowed forward with a selection of 55 languages not even remotely representative of Earth. But when the delegates showed up at the UN Headquarters, it quickly became clear that none was satisfied with a simple “Hello” and each wanted to make a speech. Some read poetry from their home nation. Others spoke in Esperanto, the now-defunct “universal language.” The Nigerian delegate included the following endearing sentence:
As you probably know, my country is situated on the west coast of the continent of Africa, a land mass more or less in the shape of a question mark in the center of our planet.
Despite Sagan’s best efforts to keep the project away from the press during the time of the recording, the United Nations, unbeknownst to him, had issued a press release announcing the recording session. The next day, Sagan also discovered that Kurt Waldheim, Secretary General of the United Nations, had made a recording himself. Though the team never requested it, “the speech was so sensitively and gracefully composed, and so appropriate in its sentiments” that they felt they must include it:
As the Secretary General of the United Nations, an organization of 147 member states who represent almost all of the human inhabitants of the planet Earth, I send greetings on behalf of the people of our planet. We step out of our solar system into the universe seeking only peace and friendship, to teach if we are called upon, to be taught if we are fortunate. We know full well that our planet and all its inhabitants are but a small part of the immense universes that surrounds us and it is with humility and hope that we take this step.
Since they were including the Secretary General’s message, Sagan thought it appropriate to at least give the President of the United States the opportunity to contribute one as well. To his surprise and delight, President Jimmy Carter eagerly complied, electing to have his message — one of breathtaking optimism — as text rather than audio:
This is a present from a small distant world, a token of our sounds, our science, our images, our music, our thoughts and our feelings. We are attempting to survive our time so we may live into yours. We hope someday, having solved the problems we face, to join a community of galactic civilizations. This record represents our hope and our determination, and our good will in a vast and awesome universe.
But the most eloquent and moving encapsulation of the spirit of the Golden Record comes from Sagan himself, who extracts from the adventure in musicology a beautiful metaphor for the essence of the project in reflecting on a “charming and powerful tradition” in Javanese gamelan music, which they serendipitously discovered over the course of the research:
There is, it is said, a kind of spirit music in the world, continuously but silently playing. When a gamelan orchestra performs, it is merely making audible the present movement of the music of eternity. Perhaps all of the Voyager record can be viewed similarly — as a local and momentary expression of cosmic discourse, and exchange of greetings and music and information among diverse galactic species that has been in progress for billions of years.
Billions of years from now our sun, then a distended red giant star, will have reduced Earth to a charred cinder. But the Voyager record will still be largely intact, in some other remote region of the Milky Way galaxy, preserving a murmur of an ancient civilization that once flourished — perhaps before moving on to greater deeds and other worlds — on the distant planet Earth.
In the epilogue to Murmurs of Earth, which is an absolutely wonderful and priceless piece of cultural heritage, Sagan reflects on the legacy of the Golden Record:
One thing would be clear about us: no one sends such a message on such a journey, to other worlds and beings, without a positive passion for the future. For all the possible vagaries of the message, they could be sure that we were a species endowed with hope and perseverance, at least a little intelligence, substantial generosity and a palpable zest to make contact with the cosmos.
In a chapter titled “The Fine Art of Baloney Detection,” Sagan reflects on the many types of deception to which we’re susceptible — from psychics to religious zealotry to paid product endorsements by scientists, which he held in especially low regard, noting that they “betray contempt for the intelligence of their customers” and “introduce an insidious corruption of popular attitudes about scientific objectivity.” (Cue in PBS’s Joe Hanson on how to read science news.) But rather than preaching from the ivory tower of self-righteousness, Sagan approaches the subject from the most vulnerable of places — having just lost both of his parents, he reflects on the all too human allure of promises of supernatural reunions in the afterlife, reminding us that falling for such fictions doesn’t make us stupid or bad people, but simply means that we need to equip ourselves with the right tools against them.
Through their training, scientists are equipped with what Sagan calls a “baloney detection kit” — a set of cognitive tools and techniques that fortify the mind against penetration by falsehoods:
The kit is brought out as a matter of course whenever new ideas are offered for consideration. If the new idea survives examination by the tools in our kit, we grant it warm, although tentative, acceptance. If you’re so inclined, if you don’t want to buy baloney even when it’s reassuring to do so, there are precautions that can be taken; there’s a tried-and-true, consumer-tested method.
But the kit, Sagan argues, isn’t merely a tool of science — rather, it contains invaluable tools of healthy skepticism that apply just as elegantly, and just as necessarily, to everyday life. By adopting the kit, we can all shield ourselves against clueless guile and deliberate manipulation. Sagan shares nine of these tools:
Wherever possible there must be independent confirmation of the “facts.”
Encourage substantive debate on the evidence by knowledgeable proponents of all points of view.
Arguments from authority carry little weight — “authorities” have made mistakes in the past. They will do so again in the future. Perhaps a better way to say it is that in science there are no authorities; at most, there are experts.
Spin more than one hypothesis. If there’s something to be explained, think of all the different ways in which it could be explained. Then think of tests by which you might systematically disprove each of the alternatives. What survives, the hypothesis that resists disproof in this Darwinian selection among “multiple working hypotheses,” has a much better chance of being the right answer than if you had simply run with the first idea that caught your fancy.
Try not to get overly attached to a hypothesis just because it’s yours. It’s only a way station in the pursuit of knowledge. Ask yourself why you like the idea. Compare it fairly with the alternatives. See if you can find reasons for rejecting it. If you don’t, others will.
Quantify. If whatever it is you’re explaining has some measure, some numerical quantity attached to it, you’ll be much better able to discriminate among competing hypotheses. What is vague and qualitative is open to many explanations. Of course there are truths to be sought in the many qualitative issues we are obliged to confront, but finding them is more challenging.
If there’s a chain of argument, every link in the chain must work (including the premise) — not just most of them.
Occam’s Razor. This convenient rule-of-thumb urges us when faced with two hypotheses that explain the data equally well to choose the simpler.
Always ask whether the hypothesis can be, at least in principle, falsified. Propositions that are untestable, unfalsifiable are not worth much. Consider the grand idea that our Universe and everything in it is just an elementary particle — an electron, say — in a much bigger Cosmos. But if we can never acquire information from outside our Universe, is not the idea incapable of disproof? You must be able to check assertions out. Inveterate skeptics must be given the chance to follow your reasoning, to duplicate your experiments and see if they get the same result.
Just as important as learning these helpful tools, however, is unlearning and avoiding the most common pitfalls of common sense. Reminding us of where society is most vulnerable to those, Sagan writes:
In addition to teaching us what to do when evaluating a claim to knowledge, any good baloney detection kit must also teach us what not to do. It helps us recognize the most common and perilous fallacies of logic and rhetoric. Many good examples can be found in religion and politics, because their practitioners are so often obliged to justify two contradictory propositions.
ad hominem — Latin for “to the man,” attacking the arguer and not the argument (e.g., The Reverend Dr. Smith is a known Biblical fundamentalist, so her objections to evolution need not be taken seriously)
argument from authority (e.g., President Richard Nixon should be re-elected because he has a secret plan to end the war in Southeast Asia — but because it was secret, there was no way for the electorate to evaluate it on its merits; the argument amounted to trusting him because he was President: a mistake, as it turned out)
argument from adverse consequences (e.g., A God meting out punishment and reward must exist, because if He didn’t, society would be much more lawless and dangerous — perhaps even ungovernable. Or: The defendant in a widely publicized murder trial must be found guilty; otherwise, it will be an encouragement for other men to murder their wives)
appeal to ignorance — the claim that whatever has not been proved false must be true, and vice versa (e.g., There is no compelling evidence that UFOs are not visiting the Earth; therefore UFOs exist — and there is intelligent life elsewhere in the Universe. Or: There may be seventy kazillion other worlds, but not one is known to have the moral advancement of the Earth, so we’re still central to the Universe.) This impatience with ambiguity can be criticized in the phrase: absence of evidence is not evidence of absence.
special pleading, often to rescue a proposition in deep rhetorical trouble (e.g., How can a merciful God condemn future generations to torment because, against orders, one woman induced one man to eat an apple? Special plead: you don’t understand the subtle Doctrine of Free Will. Or: How can there be an equally godlike Father, Son, and Holy Ghost in the same Person? Special plead: You don’t understand the Divine Mystery of the Trinity. Or: How could God permit the followers of Judaism, Christianity, and Islam — each in their own way enjoined to heroic measures of loving kindness and compassion — to have perpetrated so much cruelty for so long? Special plead: You don’t understand Free Will again. And anyway, God moves in mysterious ways.)
begging the question, also called assuming the answer (e.g., We must institute the death penalty to discourage violent crime. But does the violent crime rate in fact fall when the death penalty is imposed? Or: The stock market fell yesterday because of a technical adjustment and profit-taking by investors — but is there any independent evidence for the causal role of “adjustment” and profit-taking; have we learned anything at all from this purported explanation?)
observational selection, also called the enumeration of favorable circumstances, or as the philosopher Francis Bacon described it, counting the hits and forgetting the misses (e.g., A state boasts of the Presidents it has produced, but is silent on its serial killers)
statistics of small numbers — a close relative of observational selection (e.g., “They say 1 out of every 5 people is Chinese. How is this possible? I know hundreds of people, and none of them is Chinese. Yours truly.” Or: “I’ve thrown three sevens in a row. Tonight I can’t lose.”)
misunderstanding of the nature of statistics (e.g., President Dwight Eisenhower expressing astonishment and alarm on discovering that fully half of all Americans have below average intelligence);
inconsistency (e.g., Prudently plan for the worst of which a potential military adversary is capable, but thriftily ignore scientific projections on environmental dangers because they’re not “proved.” Or: Attribute the declining life expectancy in the former Soviet Union to the failures of communism many years ago, but never attribute the high infant mortality rate in the United States (now highest of the major industrial nations) to the failures of capitalism. Or: Consider it reasonable for the Universe to continue to exist forever into the future, but judge absurd the possibility that it has infinite duration into the past);
non sequitur — Latin for “It doesn’t follow” (e.g., Our nation will prevail because God is great. But nearly every nation pretends this to be true; the German formulation was “Gott mit uns”). Often those falling into the non sequitur fallacy have simply failed to recognize alternative possibilities;
post hoc, ergo propter hoc — Latin for “It happened after, so it was caused by” (e.g., Jaime Cardinal Sin, Archbishop of Manila: “I know of … a 26-year-old who looks 60 because she takes [contraceptive] pills.” Or: Before women got the vote, there were no nuclear weapons)
meaningless question (e.g., What happens when an irresistible force meets an immovable object? But if there is such a thing as an irresistible force there can be no immovable objects, and vice versa)
excluded middle, or false dichotomy — considering only the two extremes in a continuum of intermediate possibilities (e.g., “Sure, take his side; my husband’s perfect; I’m always wrong.” Or: “Either you love your country or you hate it.” Or: “If you’re not part of the solution, you’re part of the problem”)
short-term vs. long-term — a subset of the excluded middle, but so important I’ve pulled it out for special attention (e.g., We can’t afford programs to feed malnourished children and educate pre-school kids. We need to urgently deal with crime on the streets. Or: Why explore space or pursue fundamental science when we have so huge a budget deficit?);
slippery slope, related to excluded middle (e.g., If we allow abortion in the first weeks of pregnancy, it will be impossible to prevent the killing of a full-term infant. Or, conversely: If the state prohibits abortion even in the ninth month, it will soon be telling us what to do with our bodies around the time of conception);
confusion of correlation and causation (e.g., A survey shows that more college graduates are homosexual than those with lesser education; therefore education makes people gay. Or: Andean earthquakes are correlated with closest approaches of the planet Uranus; therefore — despite the absence of any such correlation for the nearer, more massive planet Jupiter — the latter causes the former)
straw man — caricaturing a position to make it easier to attack (e.g., Scientists suppose that living things simply fell together by chance — a formulation that willfully ignores the central Darwinian insight, that Nature ratchets up by saving what works and discarding what doesn’t. Or — this is also a short-term/long-term fallacy — environmentalists care more for snail darters and spotted owls than they do for people)
suppressed evidence, or half-truths (e.g., An amazingly accurate and widely quoted “prophecy” of the assassination attempt on President Reagan is shown on television; but — an important detail — was it recorded before or after the event? Or: These government abuses demand revolution, even if you can’t make an omelette without breaking some eggs. Yes, but is this likely to be a revolution in which far more people are killed than under the previous regime? What does the experience of other revolutions suggest? Are all revolutions against oppressive regimes desirable and in the interests of the people?)
weasel words (e.g., The separation of powers of the U.S. Constitution specifies that the United States may not conduct a war without a declaration by Congress. On the other hand, Presidents are given control of foreign policy and the conduct of wars, which are potentially powerful tools for getting themselves re-elected. Presidents of either political party may therefore be tempted to arrange wars while waving the flag and calling the wars something else — “police actions,” “armed incursions,” “protective reaction strikes,” “pacification,” “safeguarding American interests,” and a wide variety of “operations,” such as “Operation Just Cause.” Euphemisms for war are one of a broad class of reinventions of language for political purposes. Talleyrand said, “An important art of politicians is to find new names for institutions which under old names have become odious to the public”)
Sagan ends the chapter with a necessary disclaimer:
Like all tools, the baloney detection kit can be misused, applied out of context, or even employed as a rote alternative to thinking. But applied judiciously, it can make all the difference in the world — not least in evaluating our own arguments before we present them to others.
The Demon-Haunted World is a timelessly fantastic read in its entirety, timelier than ever in a great many ways amidst our present media landscape of propaganda, pseudoscience, and various commercial motives. Complement it with Sagan on science and “God”.