"A witty saying proves nothing." -- Voltaire

I've always found that useful to keep in mind when reading threads like this.

"As an adolescent I aspired to lasting fame, I craved factual certainty, and I thirsted for a meaningful vision of human life - so I became a scientist. This is like becoming an archbishop so you can meet girls."

-- M. Cartmill

No one has ever announced that because determinism is true thermostats do not control temperature.

Robert Nozick, Philosophical Explanations, qtd. in Daniel Dennett, Elbow Room

It is a profoundly erroneous truism, repeated by all copy books and by eminent people when they are making speeches, that we should cultivate the habit of thinking of what we are doing. The precise opposite is the case. Civilization advances by extending the number of important operations which we can perform without thinking about them.

Whitehead, Alfred North (1861 - 1947), An Introduction to Mathematics.

Better our hypotheses die for our errors than ourselves.

-- Karl Popper

I forget if I've posted this before, but:

"I've noticed that the press tends to be quite accurate, except when they're writing on a subject I know something about." -- Keith F. Lynch

Freedom is understood in contrast to its various opposites. I can be free as opposed to being presently coerced. I can be free as opposed to being under some other person's general control. I can be free as opposed to being subject to delusions or insanity. I can be free as opposed to being ruled by the state in denial of ordinary personal liberties. I can be free as opposed to being in jail or prison. I can be free as opposed to living under unusually heavy personal obligations. I can be free as opposed to being burdened by bias or prejudice. I can even be free (or free spirited) as opposed to being governed by ordinary social conventions. The question that needs to be asked, and which hardly ever is asked, is whether I can be free as opposed to being causally determined. Given that some kind of causal determinism is presupposed in the very concept of human action, it would be odd if this were so. Why does anyone think that it is?

-- David Hill

Consequentialism: The belief that doing the right thing makes the world a better place.

-- DanielLC

Alice came to a fork in the road. "Which road do I take?" she asked. "Where do you want to go?" responded the Cheshire cat. "I don't know," Alice answered. "Then," said the cat, "it doesn't matter." ~Lewis Carroll, Alice in Wonderland

Try looking at your mind as a wayward puppy that you are trying to paper train. You don't drop-kick a puppy into the neighbor's yard every time it pisses on the floor. You just keep bringing it back to the newspaper. So I keep trying to gently bring my mind back to what is really there to be seen, maybe to be seen and noted with a kind of reverence. Because if I don't learn to do this, I think I'll keep getting things wrong.

-Anne Lamott, Bird by Bird

I almost believe we are ghosts, all of us. It's not just what we inherit from our fathers and mothers that walks again in us - it's all sorts of dead old ideas and dead beliefs and things like that. They don't exactly live in us, but there they sit all the same and we can't get rid of them. All I have to do is pick up a newspaper, and I see ghosts lurking between the lines. I think there are ghosts everywhere you turn in this country - as many as there are grains of sand - and then there we all are, so abysmally afraid of the light.

-- Ibsen, 1881

Albert grunted. "Do you know what happens to lads who ask too many questions?"
Mort thought for a moment.
"No," he said eventually, "what?"
There was silence.
Then Albert straightened up and said, "Damned if I know. Probably they get answers, and serve 'em right."

-Terry Pratchett, Mort

"The account of perception that’s starting to emerge is what we might call the “brain’s best guess” theory of perception: perception is the brain’s best guess about what is happening in the outside world. The mind integrates scattered, weak, rudimentary signals from a variety of sensory channels, information from past experiences, and hard-wired processes, and produces a sensory experience full of brain-provided color, sound, texture, and meaning. ... Perception is inference."[emphasis added]

- Atul Gawande

There is no opinion so absurd that some philosopher will not express it.

-- Marcus Tullius Cicero

[ while in general I value philosophy, there is also much nonsense and, especially, little progress ]

[Mathematical methods of inference] literally have no content; long division can calculate miles per gallon, or it can calculate income per capita. The statistical tools of experimental psychology were borrowed from agronomy, where they were invented to gauge the effects of different fertilizers on crop yields. The tools work just fine in psychology, even though, as one psychological statistician wrote, "we do not deal in manure, at least not knowingly."

-- Steven Pinker, How The Mind Works

Our imagination is stretched to the utmost, not, as in fiction, to imagine things which are not really there, but just to comprehend those things which are there.

-- Richard Feynman The Character of Physical Law

There’s no sense in being precise when you don’t even know what you’re talking about.

John Von Neumann

There are hardly any excesses of the most crazed psychopath that cannot easily be duplicated by a normal kindly family man who just comes in to work every day and has a job to do.

-- Terry Pratchett, Small Gods

Your job as a scientist is to figure out how you’re fooling yourself.

Saul Perlmutter

Leibniz, Gottfried Wilhelm (1646-1716): Although the whole of this life were said to be nothing but a dream and the physical world nothing but a phantasm, I should call this dream or phantasm real enough, if, using reason well, we were never deceived by it.

In J. R. Newman (ed.), The World of Mathematics, New York: Simon and Schuster, 1956.

 It's great to be able to stop
When you've planned a thing that's wrong,
And be able to do something else instead

-- Fred M. Rogers, "What Do You Do?"

"It’s hard to argue with a counter-example."

-- Roger Brockett

I sure wished I knew what the hell I was talking about, but I'd picked up enough terms and felt the importance attached to them, so that I could use them properly without knowing what they meant. But they felt right, so very right...

-- Roger Zelazny, as Corwin ("Nine Princes in Amber").

Even if man really were nothing but a piano-key, even if this were proved to him by natural science and mathematics, even then he would not become reasonable, but would purposely do something perverse out of simple ingratitude, simply to gain his point.

—Fyodor Dostoyevsky, Notes from the Underground

(Self-promotion: this is the epigraph to the novella I'm working on, which is not really about rationality but is about what we're pleased to call "human nature", and which you may read the beginning of here if so inclined.)

Feedback phenomena and human intuition are uncomfortable bedfellows. When people dislike where an equilibrium argument takes them, it is therefore unsurprising that they invent simpler arguments that lead to more palatable conclusions. However, the first principle of rational thought is never to allow your preferences to influence your beliefs.

Ken Binmore

"If you’ve never missed a flight, you’re spending too much time in airports."

-- Umesh Vazirani (as quoted by Scott Aaronson)

True, it would be some kind of bland comfort if no one had any cause for which they would be willing to kill. It would be an unimaginable horror, though, if no one had a cause for which they were willing to die.

-- Tailsteak

"Most men are so thoroughly subjective that nothing really interests them but themselves. They always think of their own case as soon as any remark is made, and their whole attention is engrossed and absorbed by the merest chance reference to anything which affects them personally, be it never so remote: with the result that they have no power left for forming an objective view of things, should the conversation take that turn; neither can they admit any validity in arguments which tell against their interest or their vanity."

Arthur Schopenhauer (1788-1860)

Whenever you find yourself on the side of the majority, it's time to pause and reflect.

-Mark Twain

Believe those who are seeking the truth. Doubt those who find it. ~Andre Gide

The trouble was that he was talking in philosophy, but they were listening in gibberish.

-- Terry Pratchett, Small Gods

“To rationalize their lies, people -- and the governments, churches, or terrorist cells they compose -- are apt to regard their private interests and desires as just.”

--Wendy Kaminer (A woman social activist)

Do not believe in anything simply because you have heard it. Do not believe in anything simply because it is spoken and rumored by many. Do not believe in anything simply because it is found written in your religious books. Do not believe in anything merely on the authority of your teachers and elders. Do not believe in traditions because they have been handed down for many generations. But after observation and analysis, when you find that anything agrees with reason and is conducive to the good and benefit of one and all, then accept it and live up to it.

-Buddha

"It only stands to reason that where there's sacrifice, there's someone collecting the sacrificial offerings. Where there's service, there is someone being served. The man > who speaks to you of sacrifice is speaking of slaves and masters, and intends to be the master."

~ Ayn Rand, Atlas Shrugged

[ I'm actually not too fond of objectivism, but this quote is spot-on ]

In sane moments we regard only the facts, the case that is. Say what you have to say, not what you ought. Any truth is better than make-believe.

-- Henry David Thoreau, Walden

The problem with engineers is that they tend to cheat in order to get results.

The problem with mathematicians is that they tend to work on toy problems in order to get results.

The problem with program verifiers is that they tend to cheat on toy programs in order to get results.

the UNIX fortune-cookie program; original source unknown

[T]he dogmatist within is always worse than the enemy without.

-- Stephen Jay Gould

The study of mathematics cannot be replaced by any other activity that will train and develop man’s purely logical faculties to the same level of rationality.

Cletus O. Oakley

It cannot be that axioms established by argumentation should avail for the discovery of new works, since the subtlety of nature is greater many times over than the subtlety of argument. But axioms duly and orderly formed from particulars easily discover the way to new particulars, and thus render sciences active.

Francis Bacon

Whenever, then, anything in nature seems to us ridiculous, absurd or evil, it is because we have but a partial knowledge of things, and are in the main ignorant of order and coherence of nature as a whole, and because we want everything to be arranged according to dictates of our own reason; although in fact, what our reason pronounces bad is not as bad as regards the order and laws of universal nature, but only as regards the order and laws of our own nature taken separately.... As for the terms good and bad, they indicate nothing positive considered in themselves...For one and the same thing can at the same time be good, bad and indifferent. For example, music is good to the melancholy, bad to mourners and indifferent to the dead. ---Spinoza

From the story of philosophy by Will durant

"God ha' mercy! What cannot be racked from words in five centuries? One could wring, methinks, a flood from a damp clout!"

Shakespeare in the 20th century, as imagined by Isaac Asimov in "The Immortal Bard".

When even fourth grade starts looking good Which you hated And first grade's looking good too Overrated And you boys long for some little girl that you dated Do you long for her or for the way you were?

A verse from Jonathan Richman's song, "Summer Feeling," on memory.

Your strength as a rationalist is your ability to be more confused by fiction than by reality.

--Eliezer (http://lesswrong.com/lw/if/your_strength_as_a_rationalist/)

"Do not be too moral. You may cheat yourself out of much life. Aim above morality. Be not simply good; be good for something" Thoreau

A saint may fight against a knave. Alternatively, two knaves may fight. A dragon may be slain by St. George, or by another dragon. In the former case you are left with St. George, who deserves a reward for slaying his dragon. In the latter case you are faced with a dragon, which did only what dragons do. He was probably the bigger of the two, and now he is even bigger than that.

-- Mencius Moldbug, teaching us how to argue any point persuasively. (In this example he's talking about the Allies vs Nazi Germany.)

"Now we've got a truth to die for!" "No. Men should die for lies. But the truth is too precious to die for."

-- Terry Pratchett, Small Gods

More than ambition, more than ability, it is rules that limit contribution; rules are the lowest common denominator of human behavior. They are a substitute for rational thought.

Hyman G. Rickover

"You can't tell what someone is doing by watching what they're doing."

-- Richard Marken

"Action speaks nothing, without the Motive."

-- anonymous fortune cookie

Mencius said, "Whenever anyone told him that he had made a mistake, Tzu-lu was delighted. Whenever he heard a fine saying, Yü bowed low before the speaker. The Great Shun was even greater. He was ever ready to fall into line with others, giving up his own ways for theirs, and glad to take from others that by which he could do good."

"If two men are fighting and the wife of one of them comes to rescue her husband from his assailant, and she reaches out and seizes him by his private parts, you shall cut off her hand. Show her no pity."

-- Deuteronomy 25:11-12 (New International Version)

"We are not rational, we're rationalizing". (hope this is still in the spirit of the blog...i think)