The Demon-Haunted World_ Science as a Candle in the Dark - Carl Sagan [103]
[* A more cynical formulation by the Roman historian Polybius: Since the masses of the people are inconstant, full of unruly desires, passionate, and reckless of consequences, they must be filled with fears to keep them in order. The ancients did well, therefore, to invent gods, and the belief in punishment after death.]
• 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 unending 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 favourable 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).
[* My favourite example is this story, told about the Italian physicist Enrico Fermi, newly arrived on American shores, enlisted in the Manhattan nuclear weapons project, and brought face-to-face in the midst of World War Two with US flag officers:
So-and-so is a great general, he was told.
‘What is the definition of a great general?’ Fermi characteristically asked.
‘I guess it’s a general who’s won many consecutive battles.’
‘How many?’
After some back and forth, they settled on five.
‘What fraction of American generals are great?’
After some more back and forth, they settled on a few per cent. 1 But imagine, Fermi rejoined, that there is no such thing as a great general, that all armies are equally matched, and that winning a battle is purely a matter of chance. Then the chance of winning one battle is one out of two, or 1/2; two battles 1/4, three 1/8, four 1/16, and five consecutive battles 1/32, which is about three per cent. You would expect a few per cent of American generals to win five consecutive battles, purely by chance. Now, has any of them won ten consecutive battles...?]
• Statistics of small numbers - a close relative of observational selection (e.g., ‘they say 1 out of 5 people is Chinese. How is this possible? I know hundreds of people, and none of them is Chinese. Yours truly.’ Or: V’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