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The second volume of the Less Wrong book Rationality: From AI to Zombies. This book would not have been possible without the help of our Kickstarter backers.
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"A curious aspect of the theory of evolution," said Jacques Monod, "is that everybody thinks he understands it." A human being, looking at the natural world, se
Followup to: An Alien God The wonder of evolution is that it works at all. I mean that literally: If you want to marvel at evolution, that's what's marvel-wor
Followup to: An Alien God, The Wonder of Evolution Yesterday, I wrote: Science has a very exact idea of the capabilities of evolution. If you praise evolutio
"The laws of physics and the rules of math don't cease to apply. That leads me to believe that evolution doesn't stop. That further leads me to believe
Followup to: Evolutions Are Stupid It is a very common misconception that an evolution works for the good of its species. Can you remember hearing someone tal
Before 1966, it was not unusual to see serious biologists advocating evolutionary hypotheses that we would now regard as magical thinking. These muddled notion
Followup to: Fake Justification, The Tragedy of Group Selectionism I've previously dwelt in considerable length upon forms of rationalization whereby our beliefs appear to match the evidence much more strongly than they actually do. And I'm not overemphasizing the point, either.
"Individual organisms are best thought of as adaptation-executers rather than as fitness-maximizers." -John Tooby and Leda Cosmides, The Psychological F
Followup to: An Alien God, Adaptation-Executers not Fitness-Maximizers Like "IRC chat" or "TCP/IP protocol", the phrase "reproductive organ" is redundant. All
Followup to: Adaptation-Executers not Fitness-Maximizers, The Evolutionary-Cognitive Boundary "In a 1989 Canadian study, adults were asked to imagine the death
At least three people have died playing online games for days without rest. People have lost their spouses, jobs, and children to World of Warcraft. If people
Followup to: An Alien God, Adaptation-Executers not Fitness-Maximizers, Evolutionary Psychology Before the 20th century, not a single human being had an explic
Previously in series: Expected Creative Surprises Since I am so uncertain of Kasparov's moves, what is the empirical content of my belief that "Kasparov is a
Followup to: The Psychological Unity of Humankind Many times the human species has travelled into space, only to find the stars inhabited by aliens who look r
Lest anyone get the wrong impression, I'm juggling multiple balls right now and can't give the latest Singularity debate as much attention as it deserves. But lest I annoy my esteemed co-blogger, here is a down payment on my views of the Singularity - needless to say, all this is coming way out of order in the posting sequence, but here goes...
Followup to: The Ultimate Source, Passing the Recursive Buck People hear about Friendly AI and say - this is one of the top three initial reactions: "Oh, you c
On a purely instinctive level, any human planner behaves as if they distinguish between means and ends. Want chocolate? There's chocolate at the Publix superm
Followup to: Terminal Values and Instrumental Values Are apples good to eat? Usually, but some apples are rotten. Do humans have ten fingers? Most of us do
Followup to: The Tragedy of Group Selectionism, Fake Optimization Criteria, Terminal Values and Instrumental Values, Artificial Addition, Leaky Generalizations
Followup to: Humans in Funny Suits, The Tragedy of Group Selectionism The core fallacy of anthropomorphism is expecting something to be predicted by the black
It was in either kindergarten or first grade that I was first asked to pray, given a transliteration of a Hebrew prayer. I asked what the words meant. I was t
Once upon a time, there was a court jester who dabbled in logic. The jester presented the king with two boxes. Upon the first box was inscribed: "Either this
Followup to: The Parable of the Dagger "All men are mortal. Socrates is a man. Therefore Socrates is mortal." - Aristotle(?) Socrates raised the glass of hemlock to his lips... "Do you suppose," asked one of the onlookers, "that even hemlock will not be enough to kill so wise and good a man?"
Followup to: Words as Hidden Inferences "What is red?""Red is a color.""What's a color?""A color is a property of a thing." But what is a thing? And what's a property? Soon the two are lost in a maze of words defined in other words, the problem that Steven Harnad once described as trying to learn Chinese from a Chinese/Chinese dictionary.
Followup to: Extensions and Intensions Once upon a time, the philosophers of Plato's Academy claimed that the best definition of human was a "featherless biped". Diogenes of Sinope, also called Diogenes the Cynic, is said to have promptly exhibited a plucked chicken and declared "Here is Plato's man."
Followup to: Similarity Clusters Birds fly. Well, except ostriches don't. But which is a more typical bird-a robin, or an ostrich?Which is a more typical cha
Followup to: Typicality and Asymmetrical Similarity The notion of a "configuration space" is a way of translating object descriptions into object positions. It may seem like blue is "closer" to blue-green than to red, but how much closer? It's hard to answer that question by just staring at the colors.
Followup to: The Cluster Structure of Thingspace Imagine that you have a peculiar job in a peculiar factory: Your task is to take objects from a mysterious co
Followup to: Disguised Queries In Disguised Queries, I talked about a classification task of "bleggs" and "rubes". The typical blegg is blue, egg-shaped, furred, flexible, opaque, glows in the dark, and contains vanadium. The typical rube is red, cube-shaped, smooth, hard, translucent, unglowing, and contains palladium.
Followup to: Neural Categories "If a tree falls in the forest, and no one hears it, does it make a sound?" I remember seeing an actual argument get started on
Followup to: How An Algorithm Feels From Inside I have watched more than one conversation-even conversations supposedly about cognitive science-go the route of
Followup to: Disputing Definitions When I hear someone say, "Oh, look, a butterfly," the spoken phonemes "butterfly" enter my ear and vibrate on my ear drum, being transmitted to the cochlea, tickling auditory nerves that transmit activation spikes to the auditory cortex, where phoneme processing begins, along with recognition of words, and reconstruction of syntax (a by no means serial process), and all manner of other complications.
Followup to: Feel the Meaning Part of the Standard Definitional Dispute runs as follows: Albert: "Look, suppose that I left a microphone in the forest and recorded the pattern of the acoustic vibrations of the tree falling. If I played that back to someone, they'd call it a 'sound'!
Followup to: The Argument from Common Usage Consider (yet again) the Aristotelian idea of categories. Let's say that there's some object with properties A, B, C, D, and E, or at least it looks E-ish.
Followup to: Empty Labels In the game Taboo (by Hasbro), the objective is for a player to have their partner guess a word written on a card, without using that
What does it take to-as in yesterday's example-see a "baseball game" as "An artificial group conflict in which you use a long wooden cylinder to whack a thrown spheroid, and then run between four safe positions"?
Followup to: Replace the Symbol with the Substance "The map is not the territory," as the saying goes. The only life-size, atomically detailed, 100% accurate map of California is California. But California has important regularities, such as the shape of its highways, that can be described using vastly less information-not to mention vastly less physical material-than it would take to describe every atom within the state borders.
Followup to: Fallacies of Compression Among the many genetic variations and mutations you carry in your genome, there are a very few alleles you probably know-including those determining your blood type: the presence or absence of the A, B, and + antigens.
Followup to: Categorizing Has Consequences Yesterday, we saw that in Japan, blood types have taken the place of astrology-if your blood type is AB, for example, you're supposed to be "cool and controlled". So suppose we decided to invent a new word, "wiggin", and defined this word to mean people with green eyes and black hair- A green-eyed man with black hair walked into a restaurant.
Followup to: Sneaking in Connotations "This plucked chicken has two legs and no feathers-therefore, by definition, it is a human!" When people argue definition
Followup to: Arguing "By Definition" The one comes to you and says: Long have I pondered the meaning of the word "Art", and at last I've found what seems to m
Followup to: Where to Draw the Boundary? Suppose you have a system X that's equally likely to be in any of 8 possible states: {X1, X2, X3, X4, X5, X6, X7, X8.
Continuation of: Entropy, and Short Codes Suppose you have a system X that can be in any of 8 states, which are all equally probable (relative to your current state of knowledge), and a system Y that can be in any of 4 states, all equally probable.
Followup to: Mutual Information, and Density in Thingspace Thingspace, you might think, is a rather huge space. Much larger than reality, for where reality only contains things that actually exist, Thingspace contains everything that could exist.
Followup to: Searching for Bayes-Structure Previously I spoke of mutual information between X and Y, I(X;Y), which is the difference between the of the joint probability distribution, H(X,Y) and the entropies of the marginal distributions, H(X) + H(Y).
Followup to: Conditional Independence, and Naive Bayes (We should be done with the mathy posts, I think, at least for now. But forgive me if, ironically, I en
Followup to: Words as Mental Paintbrush Handles Albert: "Every time I've listened to a tree fall, it made a sound, so I'll guess that other trees falling als
Followup to: Just about every post in February, and some in March Some reader is bound to declare that a better title for this post would be "37 Ways That You
Bayes' Theorem for the curious and bewildered; an excruciatingly gentle introduction.
In L. Sprague de Camp's fantasy story The Incomplete Enchanter (which set the mold for the many imitations that followed), the hero, Harold Shea, is transported
Followup to: Universal Fire Antoine-Laurent de Lavoisier discovered that breathing (respiration) and fire (combustion) operated on the same principle. It was
Followup to: Beautiful Math, Expecting Beauty Yesterday I talked about the cubes {1, 8, 27, 64, 125, ...} and how their first differences {7, 19, 37, 61, ...}
Followup to: Beautiful Math, Expecting Beauty, Is Reality Ugly? Should we expect rationality to be, on some level, simple? Should we search and hope for under
"Outside the laboratory, scientists are no wiser than anyone else." Sometimes this proverb is spoken by scientists, humbly, sadly, to remind themselves of thei
Followup to: Superexponential Conceptspace, and Simple Words The first law of thermodynamics, better known as Conservation of Energy, says that you can't crea
Followup to: The Second Law of Thermodynamics, and Engines of Cognition Yesterday's post concluded: To form accurate beliefs about something, you really do h
Followup to: Perpetual Motion Beliefs"Gnomish helms should not function. Their very construction seems to defy the nature of thaumaturgical law. In fact, the
Followup to: How an Algorithm Feels From the Inside, Feel the Meaning, Replace the Symbol with the Substance "If a tree falls in the forest, but no one hears i
Followup to: Dissolving the Question, Mysterious Answers to Mysterious Questions Where the mind cuts against reality's grain, it generates wrong questions-ques
Followup to: How an Algorithm Feels from the Inside, Dissolving the Question, Wrong Questions When you are faced with an unanswerable question-a question to wh
Followup to: How an Algorithm Feels From Inside In the dawn days of science fiction, alien invaders would occasionally kidnap a girl in a torn dress and carry
Followup to: The Mind Projection Fallacy Yesterday I spoke of the Mind Projection Fallacy, giving the example of the alien monster who carries off a girl in a
Followup to: The Mind Projection Fallacy, Probability is in the Mind In classical logic, the operational definition of identity is that whenever 'A=B' is a theorem, you can substitute 'A' for 'B' in any theorem where B appears.
Followup to: Probability is in the Mind, The Quotation is not the Referent I suggest that a primary cause of confusion about the distinction between "belief",
Whenever I hear someone describe quantum physics as "weird" - whenever I hear someone bewailing the mysterious effects of observation on the observed, or the bi
I was recently having a conversation with some friends on the topic of hour-by-hour productivity and willpower maintenance-something I've struggled with my whol
Followup to: How An Algorithm Feels From Inside, Mind Projection Fallacy Almost one year ago, in April 2007, Matthew C submitted the following suggestion for a
Followup to: Reductionism, Righting a Wrong Question John Keats's Lamia (1819) surely deserves some kind of award for Most Famously Annoying Poetry:
Followup to: Explaining vs. Explaining Away, Fake Explanation There was an awful rainbow once in heaven: We know her woof, her texture; she is given In the du
Followup to: Explaining vs. Explaining Away "Poets say science takes away from the beauty of the stars-mere globs of gas atoms. Nothing is "mere". I too
Followup to: Explaining vs. Explaining Away ...Do not all charms fly At the mere touch of cold philosophy? There was an awful rainbow once in heaven: We know her woof, her texture; she is given In the dull catalogue of common things. -John Keats, Lamia "Nothing is 'mere'."
Followup to: Joy in the Merely Real "Newton was the greatest genius who ever lived, and the most fortunate; for we cannot find more than once a system of the
Followup to: Joy in the Merely Real So perhaps you're reading all this, and asking: "Yes, but what does this have to do with reductionism?" Partially, it's a matter of leaving a line of retreat. It's not easy to take something important apart into components, when you're convinced that this removes magic from the world, unweaves the rainbow.
Followup to: Explaining vs. Explaining Away, Joy in the Merely Real Most witches don't believe in gods. They know that the gods exist, of course. They even
Followup to: Joy in the Merely Real, Joy in Discovery, If You Demand Magic, Magic Won't Help As you may recall from some months earlier, I think that part of t
Facts do not need to be unexplainable, to be beautiful; truths do not become less worth learning, if someone else knows them; beliefs do not become less worthwhile, if many others share them... ...and if you only care about scientific issues that are controversial, you will end up with a head stuffed full of garbage.
So you're thinking, "April 1st... isn't that already supposed to be April Fool's Day?" Yes-and that will provide the ideal cover for celebrating Amazing Breakthrough Day. As I argued in " The Beauty of Settled Science", it is a major problem that media coverage of science focuses only on breaking news.
Followup to: Bind Yourself to Reality For many years before the Wright Brothers, people dreamed of flying with magic potions. There was nothing irrational abo
What follows is taken primarily from Robert Cialdini's Influence: The Psychology of Persuasion. I own three copies of this book, one for myself, and two for loaning to friends. S carcity, as that term is used in social psychology, is when things become more desirable as they appear less obtainable.
Followup to: Is Humanism a Religion-Substitute? So I was reading (around the first half of) Adam Frank's The Constant Fire, in preparation for my Bloggingheads
Followup to: Joy in Discovery, Bind Yourself to Reality, Scientific Evidence, Scarcity Sometimes I wonder if the Pythagoreans had the right idea. Yes, I've wri
The torches that lit the narrow stairwell burned intensely and in the wrong color, flame like melting gold or shattered suns. 192... 193... Brennan's
Followup to: Reductionism, Explaining vs. Explaining Away, Fake Reductionism Back to our original topic: Reductionism, which (in case you've forgotten) is par
Followup to: Hand vs. Fingers Fundamental physics-quarks 'n stuff-is far removed from the levels we can see, like hands and fingers. At best, you can know how
Followup to: Angry Atoms After yesterday's post, it occurred to me that there's a much simpler example of reductionism jumping a gap of apparent-difference-in-
In an amazing breakthrough, a multinational team of scientists led by Nobel laureate Santiago Ramón y Cajal announced that the brain is composed of a ridiculously complicated network of tiny cells connected to each other by infinitesimal threads and branches.
Followup to: Humans in Funny Suits, Brain Breakthrough It turns out that most things in the universe don't have minds. This statement would have provoked incredulity among many earlier cultures. " Animism" is the usual term. They thought that trees, rocks, streams, and hills all had spirits because, hey, why not?
See also: Comments on "How to Convince Me That 2 + 2 = 3" Traditional Rationality is phrased as social rules, with violations interpretable as cheating: if yo
Followup to: Reductionism, Explaining vs. Explaining Away, Hand vs. Fingers, Heat vs. Motion The reductionist thesis (as I formulate it) is that human minds, f
Your "zombie", in the philosophical usage of the term, is putatively a being that is exactly like you in every respect-identical behavior, identical speech, ide
Continuation of: Zombies! Zombies? I'm a bit tired today, having stayed up until 3AM writing yesterday's >6000-word post on zombies, so today I'll just reply t
Followup to: Zombies! Zombies? "Each problem that I solved became a rule which served afterwards to solve other problems." -Rene Descartes, Discours de
Followup to: The Generalized Anti-Zombie Principle In "The Unimagined Preposterousness of Zombies", Daniel Dennett says: To date, several philosophers have to
Followup to: The Generalized Anti-Zombie Principle One generalized lesson not to learn from the Anti-Zombie Argument is, "Anything you can't see doesn't exist.
FADE IN around a serious-looking group of uniformed military officers. At the head of the table, a senior, heavy-set man, GENERAL FRED, speaks. GENERAL FRED:
Followup to: Reductionism, Anthropomorphic Optimism Occasionally, you hear someone claiming that creationism should not be taught in schools, especially not as
Followup to: Excluding the Supernatural Yesterday, I wrote: If the "boring view" of reality is correct, then you can never predict anything irreducible because
I think I must now temporarily digress from the sequence on zombies (which was a digression from the discussion of reductionism, which was a digression from the
Previously in series: Quantum Explanations So the universe isn't made of little billiard balls, and it isn't made of crests and troughs in a pool of aether...
Previously in series: Configurations and Amplitude The key to understanding configurations, and hence the key to understanding quantum mechanics, is realizing
Previously in series: Joint Configurations Yesterday's experiment carried two key lessons: First, we saw that because amplitude flows can cancel out, and because our magic measure of squared modulus is not linear, the identity of configurations is nailed down-you can't reorganize configurations the way you can regroup possible worlds.
Previously in series: Spooky Action at a DistanceFollowup to: Decoherence is Simple, Falsifiable and Testable Back when people didn't know about macroscopic d
An epistle to the physicists: When I was but a little lad, my father, a Ph.D. physicist, warned me sternly against meddling in the affairs of physicists; he sai
Continuation of: Decoherence is Simple The words "falsifiable" and "testable" are sometimes used interchangeably, which imprecision is the price of speaking in
Suppose that the police of Largeville, a town with a million inhabitants, are investigating a murder in which there are few or no clues-the victim was stabbed t
Followup to: Many Worlds, One Best Guess Some commenters have recently expressed disturbance at the thought of constantly splitting into zillions of other peop
Followup to: Bell's Theorem "Does the moon exist when no one is looking at it?" -Albert Einstein, asked of Niels Bohr Suppose you were just starting t
Followup to: Collapse Postulates, Decoherence is Simple, Falsifiable and Testable Not that I'm claiming I could have done better, if I'd been born into that tim
Followup to: Distinct Configurations Looking back on early quantum physics-not for purposes of admonishing the major figures, or to claim that we could have done better if we'd been born into that era; but in order to try and learn a moral, and do better next time-looking back on the dark ages of quantum physics, I say, I would nominate as the "most basic" error...
Followup to: Dissolving the Question, Hand vs. Fingers, Timeless Causality, Living in Many-Worlds Three months ago-jeebers, has it really been that long?-I pos
Previously in series: Collapse PostulatesFollowup to: Bell's Theorem, Spooky Action at a Distance, Quantum Non-Realism, Decoherence is Simple, Falsifiable and
Followup to: Initiation Ceremony, If Many-Worlds Had Come First This time there were no robes, no hoods, no masks. Students were expected to become friends, a
Followup to: If Many-Worlds Had Come First, The Failures of Eld Science "Eli: You are writing a lot about physics recently. Why?" -Shane Legg (and sev
Followup to: The Dilemma: Science or Bayes? Scott Aaronson suggests that Many-Worlds and libertarianism are similar in that they are both cases of bullet-swall
Followup to: Science Doesn't Trust Your Rationality, My Wild and Reckless Youth Once upon a time, a younger Eliezer had a stupid theory. Let's say that Elieze
Followup to: When Science Can't Help Once upon a time, a younger Eliezer had a stupid theory. Eliezer18 was careful to follow the precepts of Traditional Rati
Followup to: Science Isn't Strict Enough poke alleges: "Being able to create relevant hypotheses is an important skill and one a scientist spends a great deal
Followup to: Science Doesn't Trust Your Rationality, Do Scientists Already Know This Stuff? I don't ask my friends about their childhoods-I lack social curiosi
New Scientist on changing the definition of science, ungated here: Others believe such criticism is based on a misunderstanding. "Some people say that the multiverse concept isn't falsifiable because it's unobservable-but that's a fallacy," says cosmologist Max Tegmark of the Massachusetts Institute of Technology.
Followup to: Science Doesn't Trust Your Rationality, Einstein's Arrogance I sometimes say that the method of science is to amass such an enormous mountain of evidence that even scientists cannot ignore it; and that this is the distinguishing characteristic of a scientist, a non-scientist will ignore it anyway.
Followup to: Faster Than Science Yesterday I argued that the Powers Beyond Science are actually a standard and necessary part of the social process of science.
Followup to: Einstein's Speed Imagine a world much like this one, in which, thanks to gene-selection technologies, the average IQ is 140 (on our scale). Poten
Followup to: That Alien Message When I lecture on the Singularity, I often draw a graph of the "scale of intelligence" as it appears in everyday life: But thi
Followup to: Einstein's Speed, My Childhood Role Model, Timeless Physics There is a widespread tendency to talk (and think) as if Einstein, Newton, and similar
Followup to: The Failures of Eld Science, Einstein's Superpowers "Do as well as Einstein?" Jeffreyssai said, incredulously. "Just as well as Einstein? Albert
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