Source: Zen and the Art of Motorcycle Maintenance (1974), Ch. 22; the quote is from Poincaré's The Foundations of Science, ch. 12, "Optics and Electricity".
Si donc un phénomène comporte une explication mécanique complète, il en comportera une infinité d’autres qui rendront également bien compte de toutes les particularités révélées par l’expérience.
Source: Science and Hypothesis (1901), Ch. XII: Optics and Electricity, as translated by George Bruce Halsted (1913)
Context: Of course, we must avoid postulating a new element for each new phenomenon. But an equally serious mistake is to admit into the theory only those elements which can now be observed. For the purpose of a theory is not only to correlate the results of observations that we already know how to make, but also to suggest the need for new kinds of observations and to predict their results. In fact, the better a theory is able to suggest the need for new kinds of observations and to predict their results correctly, the more confidence we have that this theory is likely to be good representation of the actual properties of matter and not simply an empirical system especially chosen in such a way as to correlate a group of already known facts.
“When all else fails, admit you’re an idiot.”
Part 2 “Mission to a Cold World”, Chapter 3 (p. 82)
A Million Open Doors (1992)
2000s, Is Diversity Good? (2003)
Context: To allow slavery to be introduced into free territories, where it had not hitherto existed, was, Abraham Lincoln held, a very bad thing. His opponent, Stephen A. Douglas, held that it was a sacred right, belonging to the people of each territory, to decide for themselves whether or not to have slavery among their domestic institutions. According to Douglas, Lincoln wanted to destroy the diversity upon which the union had subsisted, by insisting that all the states ought to be free. But for Douglas himself, the principle of 'popular sovereignty' did not admit of exceptions. There was to be no diversity, no deviation from the right of the people to decide. For Lincoln the wrongness of slavery meant that no one, and no people, had the right to decide in its favor. For Lincoln, the principle of human equality, "that all men are created equal", did not admit exceptions.
Section 10
Culture Industry Reconsidered (1963)
Context: The phrase, the world wants to be deceived, has become truer than had ever been intended. People are not only, as the saying goes, falling for the swindle; if it guarantees them even the most fleeting gratification they desire a deception which is nonetheless transparent to them. They force their eyes shut and voice approval, in a kind of self-loathing, for what is meted out to them, knowing fully the purpose for which it is manufactured. Without admitting it they sense that their lives would be completely intolerable as soon as they no longer clung to satisfactions which are none at all.
Source: A Mathematical Dictionary: Or; A Compendious Explication of All Mathematical Terms, 1702, p. 1, The Introduction; Lead paragraph
Pakistan or The Partition of India (1946)
Preface, p. 16, sentences 2,3.
The Christian Agnostic (1965)
Source: Sir William Herschel: His Life and Works (1880), Ch.4 "Life and Works" on his discovery of the infrared light.
