Thread by @leading_nowhere

Whenever you consume content and need to draw conclusions from it, refer to Carl Sagan's Baloney Detection Kit. Twelve simple logical fallacies to watch. If you spot these, you are asking the right questions.

Full piece linked at the end👇 (1/13)

(1) ad hominem—Latin for “to the man,” attacking the arguer and not the argument (e.g., The Reverend Dr. Smith is a known religious fundamentalist, so her objections to evolution need not be taken seriously); (2/13)

(2) argument from authority (e.g., Nixon should be re-elected because he has a secret plan to end war in Asia—but because it was secret, there was no way for electorate to evaluate on merits; the argument amounted to trusting because he was President: a mistake); (3/13)

(3) argument from adverse consequences (e.g., 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) (4/13)

(4) appeal to ignorance— claim that what isn't proved false must be true, and vice versa (e.g., no evidence that UFOs not visiting Earth; therefore UFOs exist—there is intelligent life elsewhere in the Universe. However, absence of evidence is not evidence of absence. (5/13)

(5) 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? (6/13)

(6) begging the question, also called assuming the answer (e.g. stock market fell because of technical adjustment and profit-taking —but is there any independent evidence for the causal role of these factors? Have we learned anything from this purported explanation?) (7/13)

(7) 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) (8/13)

(8) 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” Or: “I’ve thrown three sevens in a row. Tonight I can’t lose” (9/13)

(9) 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 - when talking of average, half people have to be above or below). (10/13)

(10) 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.” (11/14)

(11) 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. Often those falling into the non sequitur fallacy have simply failed to recognize alternative possibilities; (12/14)

(12) post hoc, ergo propter hoc—Latin for “It happened after, so it was caused by” (e.g., 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") (13/14)

The piece by Carl Sagan is linked below. Best read slowly and in full. RT the first post - it's free and brings this to more readers.

inf.fu-berlin.de/lehre/pmo/eng/…

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