A list of references and resources for LW

Updated: 2011-05-24

  • F = Free
  • E = Easy (adequate for a low educational background)
  • M = Memetic Hazard (controversial ideas or works of fiction)


Do not flinch, most of LessWrong can be read and understood by people with a previous level of education less than secondary school. (And Khan Academy followed by BetterExplained plus the help of Google and Wikipedia ought to be enough to let anyone read anything directed at the scientifically literate.) Most of these references aren't prerequisite, and only a small fraction are pertinent to any particular post on LessWrong. Do not be intimidated, just go ahead and start reading the Sequences if all this sounds too long. It's much easier to understand than this list makes it look like.

Nevertheless, as it says in the Twelve Virtues of Rationality, scholarship is a virtue, and in particular:

It is especially important to eat math and science which impinges upon rationality: Evolutionary psychology, heuristics and biases, social psychology, probability theory, decision theory.




This list is hosted on LessWrong.com, a community blog devoted to refining the art of human rationality - the art of thinking. If you follow the links below you'll learn more about this community. It is one of the most important resources you'll ever come across if your aim is to get what you want, if you want to win. It shows you that there is more to most things than meets the eye, but more often than not much less than you think. It shows you that even smart people can be completely wrong but that most people are not even wrong. It teaches you to be careful in what you emit and to be skeptical of what you receive. It doesn't tell you what is right, it teaches you how to think and to become less wrong. And to do so is in your own self interest because it helps you to attain your goals, it helps you to achieve what you want.


Why read Less Wrong?

A few articles exemplifying in detail what you can expect from reading Less Wrong, why it is important, what you can learn and how it does help you.

Artificial Intelligence

Let an ultraintelligent machine be defined as a machine that can far surpass all the intellectual activities of any man however clever. Since the design of machines is one of these intellectual activities, an ultra-intelligent machine could design even better machines; there would then unquestionably be an "intelligence explosion," and the intelligence of man would be left far behind. — I. J. Good, "Speculations Concerning the First Ultraintelligent Machine"


Friendly AI

The AI does not hate you, nor does it love you, but you are made out of atoms which it can use for something else. — Eliezer Yudkowsky, Artificial Intelligence as a Positive and Negative Factor in Global Risk

Machine Learning

Not essential but an valuable addition for anyone who's more than superficially interested in AI and machine learning.

The Technological Singularity

The term “Singularity” had a much narrower meaning back when the Singularity Institute was founded. Since then the term has acquired all sorts of unsavory connotations. — Eliezer Yudkowsky

Heuristics and Biases

One of the painful things about our time is that those who feel certainty are stupid, and those with any imagination and understanding are filled with doubt and indecision. — Bertrand Russell

Ignorance more frequently begets confidence than does knowledge. — Charles Darwin

The heuristics and biases program in cognitive psychology tries to work backward from biases (experimentally reproducible human errors) to heuristics (the underlying mechanisms at work in the brain).


Learning Mathematics

Here's a phenomenon I was surprised to find: you'll go to talks, and hear various words, whose definitions you're not so sure about. At some point you'll be able to make a sentence using those words; you won't know what the words mean, but you'll know the sentence is correct. You'll also be able to ask a question using those words. You still won't know what the words mean, but you'll know the question is interesting, and you'll want to know the answer. Then later on, you'll learn what the words mean more precisely, and your sense of how they fit together will make that learning much easier. The reason for this phenomenon is that mathematics is so rich and infinite that it is impossible to learn it systematically, and if you wait to master one topic before moving on to the next, you'll never get anywhere. Instead, you'll have tendrils of knowledge extending far from your comfort zone. Then you can later backfill from these tendrils, and extend your comfort zone; this is much easier to do than learning "forwards". (Caution: this backfilling is necessary. There can be a temptation to learn lots of fancy words and to use them in fancy sentences without being able to say precisely what you mean. You should feel free to do that, but you should always feel a pang of guilt when you do.) — Ravi Vakil




Probabilities express uncertainty, and it is only agents who can be uncertain. A blank map does not correspond to a blank territory. Ignorance is in the mind. — Eliezer Yudkowsky

Math is fundamental, not just for LessWrong. But especially Bayes’ Theorem is essential to understand the reasoning underlying most of the writings on LW.

Bayes' theorem



All the limitative theorems of metamathematics and the theory of computation suggest that once the ability to represent your own structure has reached a certain critical point, that is the kiss of death: it guarantees that you can never represent yourself totally. Gödel’s Incompleteness Theorem, Church’s Undecidability Theorem, Turing’s Halting Theorem, Tarski’s Truth Theorem — all have the flavour of some ancient fairy tale which warns you that “To seek self-knowledge is to embark on a journey which … will always be incomplete, cannot be charted on any map, will never halt, cannot be described.” — Douglas Hofstadter 1979


Decision theory

It is precisely the notion that Nature does not care about our algorithm, which frees us up to pursue the winning Way - without attachment to any particular ritual of cognition, apart from our belief that it wins. Every rule is up for grabs, except the rule of winning. — Eliezer Yudkowsky

Remember that any heuristic is bound to certain circumstances. If you want X from agent Y and the rule is that Y only gives you X if you are a devoted irrationalist then ¬irrational. Under certain circumstances what is irrational may be rational and what is rational may be irrational. Paul K. Feyerabend said: "All methodologies have their limitations and the only ‘rule’ that survives is ‘anything goes’."

Game Theory

Game theory is the study of the ways in which strategic interactions among economic agents produce outcomes with respect to the preferences (or utilities) of those agents, where the outcomes in question might have been intended by none of the agents. — Stanford Encyclopedia of Philosophy


With Release 33-9117, the SEC is considering substitution of Python or another programming language for legal English as a basis for some of its regulations. — Will Wall Street require Python?

Programming knowledge is not mandatory for LessWrong but you should however be able to interpret the most basic pseudo code as you will come across various snippets of code in discussions and top-level posts outside of the main sequences.


Python is a general-purpose high-level dynamic programming language.


Haskell is a standardized, general-purpose purely functional programming language, with non-strict semantics and strong static typing.


Computer science

The introduction of suitable abstractions is our only mental aid to organize and master complexity. — Edsger W. Dijkstra

One of the fundamental premises on LessWrong is that a universal computing device can simulate every physical process and that we therefore should be able to reverse engineer the human brain as it is fundamentally computable. That is, intelligence and consciousness are substrate-neutral.

(Algorithmic) Information Theory


A poet once said, "The whole universe is in a glass of wine." We will probably never know in what sense he meant that, for poets do not write to be understood. But it is true that if we look at a glass of wine closely enough we see the entire universe. — Richard Feynman


General relativity

You do not really understand something unless you can explain it to your grandmother. ~ Albert Einstein

Quantum physics

An electron is not a billiard ball, and it’s not a crest and trough moving through a pool of water. An electron is a mathematically different sort of entity, all the time and under all circumstances, and it has to be accepted on its own terms. The universe is not wavering between using particles and waves, unable to make up its mind. It’s only human intuitions about QM that swap back and forth. — Eliezer Yudkowsky

I am not going to tell you that quantum mechanics is weird, bizarre, confusing, or alien. QM is counterintuitive, but that is a problem with your intuitions, not a problem with quantum mechanics. Quantum mechanics has been around for billions of years before the Sun coalesced from interstellar hydrogen. Quantum mechanics was here before you were, and if you have a problem with that, you are the one who needs to change. QM sure won’t. There are no surprising facts, only models that are surprised by facts; and if a model is surprised by the facts, it is no credit to that model. — Eliezer Yudkowsky



(Evolution) is a general postulate to which all theories, all hypotheses, all systems must henceforward bow and which they must satisfy in order to be thinkable and true. Evolution is a light which illuminates all facts, a trajectory which all lines of thought must follow — this is what evolution is. — Pierre Teilhard de Chardin


There is no such thing as philosophy-free science; there is only science whose philosophical baggage is taken on board without examination. — Daniel Dennett, Darwin's Dangerous Idea, 1995.
Philosophy is a battle against the bewitchment of our intelligence by means of language. — Wittgenstein


The Mind

Everything of beauty in the world has its ultimate origins in the human mind. Even a rainbow isn't beautiful in and of itself. — Eliezer Yudkowsky


Levels of epistemic accuracy.



General Education


Not essential but a good preliminary to reading LessWrong and in some cases helpful to be able to make valuable contributions in the comments. Many of the concepts in the following works are often mentioned on LessWrong or the subject of frequent discussions.


Elaboration of miscellaneous terms, concepts and fields of knowledge you might come across in some of the subsequent and more technical advanced posts and comments on LessWrong. The following concepts are frequently discussed but not necessarily supported by the LessWrong community. Those concepts that are controversial are labeled M.


Relevant websites. News and otherwise. F

Fun & Fiction

The following are relevant works of fiction or playful treatments of fringe concepts. That means, do not take these works at face value.

Accompanying text: The Logical Fallacy of Generalization from Fictional Evidence

Memetic Hazard




A popular board game played and analysed by many people in the LessWrong and general AI crowd.


This list is a work in progress. I will try to constantly update and refine it.

If you've anything to add or correct (e.g. a broken link), please comment below and I'll update the list accordingly.