Carl Sagan Baloney Detection Kit

1995

• 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.
 …and what not to do

• 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 ambi- guity 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);

• 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?);

• 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).
!Modelo genérico de Pesquisa (Eduardo Lopes, 2017)
!a Questão que se coloca
!o Contexto em que se insere
!os Objetivos
!as Metodologias de trabalho
!os Resultados obtidos
!Divulgação