Harry Potter and the Methods of Rationality - Eliezer Yudkowsky ![rw-book-cover](https://images-na.ssl-images-amazon.com/images/I/513ex0KigYL._SL200_.jpg) ## Metadata - Author: [[Eliezer Yudkowsky]] - Full Title: Harry Potter and the Methods of Rationality - Category: #books ## Highlights - “World domination is such an ugly phrase. I prefer to call it world optimisation.” (Location 636) - But actually, since more than half the students didn’t finish by the time they were 99% sure they’d be done, reality usually delivers results a little worse than the ‘worst-case scenario’. It’s called the planning fallacy, and the best way to fix it is to ask how long things took the last time you tried them. (Location 696) - “I ask the fundamental question of rationality: why do you believe what you believe? What do you think you know and how do you think you know it? (Location 1208) - people form close friendships by knowing private things about each other, and the reason most people don’t make close friends is because they’re too embarrassed to share anything really important about themselves.” (Location 1226) - The same could be said of Draco’s clever use of reciprocation pressure with an unsolicited gift, a technique which Harry had read about in his social psychology books (Location 1230) - If magic is like casting Imperio on someone to make them do what you want, then science is like knowing them so well that you can convince them it was their own idea all along. (Location 1428) - So you have to learn how to admit you’re wrong, over and over and over again. It doesn’t sound like much, but it’s so hard that most people can’t do science. Always questioning yourself, always taking another look at things you’ve always taken for granted,” (Location 1464) - “What you’ve just discovered is called ‘positive bias’,” said the boy. “You had a rule in your mind, and you kept on thinking of triplets that should make the rule say ‘Yes’. But you didn’t try to test any triplets that should make the rule say ‘No’. In fact you didn’t get a single ‘No’, so ‘any three numbers’ could have just as easily been the rule. It’s sort of like how people imagine experiments that could confirm their hypotheses instead of trying to imagine experiments that could falsify them—that’s not quite exactly the same mistake but it’s close. (Location 1677) - That’s called consequentialism, by the way, it means that whether an act is right or wrong isn’t determined by whether it looks bad, or mean, or anything like that, the only question is how it will turn out in the end—what are the consequences.” (Location 1742) - “I’m afraid Time doesn’t like being stretched out too much,” said Dumbledore after the slight pause, “and yet we ourselves seem to be a little too large for it, and so it’s a constant struggle to fit our lives into Time.” (Location 3723) - “When we are young we believe that we know everything, and so we believe that if we see no explanation for something, then no explanation exists. When we are older we realise that the whole universe works by a rhythm and a reason, even if we ourselves do not know it. It is only our own ignorance which appears to us as insanity.” (Location 3836) - Nature isn’t a person, you can’t trick them into believing something else, if you try to tell the Moon it’s made of cheese you can argue for days and it won’t change the Moon! What you’re talking about is rationalization, (Location 5288) - When there’s a confusing problem and you’re just starting out and you have a falsifiable hypothesis, go test it. Find some simple, easy way of doing a basic check and do it right away. Don’t worry about designing an elaborate course of experiments that would make a grant proposal look impressive to a funding agency. (Location 5593) - it was simply a rule of how scientists operated that you had to try to disprove your own theories, and if you made an honest effort and failed, that was victory. (Location 5682) - And that recipe has two copies of everything, always, in case one copy is broken. Imagine two long rows of pieces of paper. At each place in the row, there are two pieces of paper, and when you have children, your body selects one piece of paper at random from each place in the row, and the mother’s body will do the same, and so the child also gets two pieces of paper at each place in the row. (Location 5910) ## New highlights added May 19, 2022 at 6:59 AM - “That your strength as a rationalist is your ability to be more confused by fiction than by reality,” (Location 6841) - The Rise and Fall of the Third Reich (Location 9283) - “The point of elections isn’t to produce the one best leader, it’s to keep politicians scared enough of the voters that they don’t go completely evil like dictators do—” (Location 9293) - if you came from somewhere that no-one had ever even heard of death, and I suggested to you that it would be an amazing wonderful great idea for people to get wrinkled and old and eventually cease to exist, why, you’d have me hauled right off to a lunatic asylum! So why would anyone possibly think any thought so silly as that death is a good thing? Because you’re afraid of it, because you don’t really want to die, and that thought hurts so much inside you that you have to rationalize it away, do something to numb the pain, so you won’t have to think about it—” (Location 10195) - “There is no justice in the laws of Nature, Headmaster, no term for fairness in the equations of motion. The universe is neither evil, nor good, it simply does not care. The stars don’t care, or the Sun, or the sky. But they don’t have to! We care! There is light in the world, and it is us!” (Location 10232) - your strongest virtue is curiosity, wondering and desiring to know the true answer. And this is not the only virtue a rationalist needs. Sometimes you have to work hard on a problem, and stick to it for a while. Sometimes you need a clever plan for finding out. And sometimes what you need more than anything else to see an answer, is the courage to face it… (Location 11080) - “I thought of my absolute rejection of death as the natural order.” (Location 11166) - Confirmation bias was the technical term; it meant, among other things, that when you chose your information sources, there was a notable tendency to choose information sources that agreed with your current opinions. (Location 11208) - “I have a dream,” said Harry’s voice, “that one day sentient beings will be judged by the patterns of their minds, and not their colour or their shape or the stuff they’re made of, or who their parents were. (Location 11779) - NEO: I’ve kept quiet for as long as I could, but I feel a certain need to speak up at this point. The human body is the most inefficient source of energy you could possibly imagine. The efficiency of a power plant at converting thermal energy into electricity decreases as you run the turbines at lower temperatures. If you had any sort of food humans could eat, it would be more efficient to burn it in a furnace than feed it to humans. And now you’re telling me that their food is the bodies of the dead, fed to the living? Haven’t you ever heard of the laws of thermodynamics? (Location 15778) - Many have stood their ground and faced the darkness when it comes for them. Fewer come for the darkness and force it to face them. It is a hard life, sometimes lonely, often short. I have told none to refuse that calling, but neither would I wish to increase their number.” (Location 16828) - Citing experimental results about keeping a gratitude journal as a strategy for improving life happiness didn’t seem like it would be taken well. (Location 17820)