Best of Rationality Quotes
The most terrifying fact about the universe is not that it is hostile but that it is indifferent, but if we can come to terms with the indifference, then our existence as a species can have genuine meaning. However vast the darkness, we must supply our own light.
— Stanley Kubrick
... unfortunately, there is a flaw in the reasoning. ... [T]o say that each of two numbers cannot be bigger than the other is to repeat the statement that is to be proved. It is not correct in logic to prove something by saying it over again; that only works in politics, and even there it is usually considered desirable to repeat the proposition hundreds of times before considering it as definitely established.
— Carl E. Linderholm, "Mathematics Made Difficult"
(There are many more good quotes to be found in this book.)
You're only as young as the last time you changed your mind.
— Timothy Leary
Ralph: When's Bart coming back?
Lisa: He's not. He thought he was better than the laws of probability. Anyone else think he's better than the laws of probability?
(Nelson raises his hand.)
Lisa: Well, you're not!
— The Simpsons, Season 22, Episode 3, "MoneyBART"
Farnsworth: My god, is it possible?
Fry: It must be possible. It's happening.
— Futurama: "The Late Philip J. Fry"
Rationality quotes: almost everything from @BadDalaiLama on Twitter.
(Edit: there's also this handy archive.)
As the mind learns to understand more complicated combinations of ideas, simpler formulae soon reduce their complexity; so truths that were discovered only by great effort, that could at first only be understood by men capable of profound thought, are soon developed and proved by methods that are not beyond the reach of common intelligence.
Marquis de Condorcet, 1794
A universe that needed someone to observe it in order to collapse it into existence would be a pretty sorry universe indeed.
— Randall Munroe, xkcd – Mutual
My definition of a stupid person: A stupid person is a person who treats a smart person as though they're stupid.
(Clearly this isn't an actual definition, but it works pretty well if you reframe it as evidence rather than as a necessary or sufficient condition.)
"A witty saying proves nothing." -- Voltaire
I've always found that useful to keep in mind when reading threads like this.