What do you mean by rationalism?

http://lesswrong.com/lw/31/what_do_we_mean_by_rationality/

What Do We Mean By 'Rationality'? (as linked below by saturn) is a good place to start, and it makes an important point: "We are not here to argue the meaning of a word, not even if that word is 'rationality'." (Or "rationalism".) That page describes the basic things-we're-trying-to-do on Less Wrong, and "rationality" is the shorthand we use to refer to those things; roughly speaking, a "rationalist" is a person who aspires to improve both their epistemic rationality and instrumental rationality (as described on that page), particularly by improving their awareness of the threats posed to their rationality by things that human brains do by default, such as the many cognitive biases and fallacies.

(And nobody here will claim that that's the One True Meaning of "rationalism"; again, with the conceptual associations it has here, it should be taken mostly as local shorthand. Many of us would argue that it's among the best of all the various things people have called "rationalism", but we know quite well that this is a claim that cannot be supported just by giving a definition.)

Off the top of my head, a few more interesting discussions on the subject of rationality as an "ism":

• Rationalists should beware rationalism
• A rational identity
• Rationality is systematized winning

I doubt "socially awkward" is used as a part of a definition of "rationalist" by anybody.

The word "rationalist" is thrown around here a lot in various contexts. There have been complaints about this before, though I am not quite sure how to locate them quickly (obviously searching the site for "rationalist" turns up quite a few results.) Here is an old discussion.

Here are a couple:

• A "rationalist" could be someone who regularly reads and/or participates on this site. A clearer term might be "LessWronger." This category of people is often intelligent, socially awkward, well educated, and has a particular techno-liberaltarian slant. Things vary but these are good guesses.
• A "rationalist" could be someone who believes in the virtues of rationality and wishes to improve themselves. This seems like an appropriate noun form of rationalist to me, although "aspiring rationalist" is a nice term I've heard.
• A "rationalist" could be someone with a specific goal, which they are concerned with pursuing as effectively as possible. A clearer term might be "rational actor."
• "Rationalist" is often used as an adjective describing arts, such as in "rationalist!fanfiction." In this context I usually interpret it to mean arts which glorify the virtues of rationality, by having heroes succeed and be awesome via planning and cross-domain thinking.

As for the statement "unencumbered by education," there are two possible interpretations I have: First, the man who started the site, Eliezer Yudkowsky, is an autodidact. References to knowledge without schooling may refer indirectly to him. Second, there is a significant and hopefully healthy amount of disrespect for authority on this site; including for academia and modern schools.

I am about 80% confident that someone has already composed this sort of a list, and that theirs is better than mine.

(I prefer to avoid the term 'rationalism' whenever possible and stick to 'rationality'. Mostly because 'rationalism' has been taken already, we have largely opposing views to that philosophy, and '-isms' should be kept narrow lest they become tainted by their weakest points/members. Buddhism, Hinduism, and libertarianism, for examples.)

Good question. But it should be answered by someone who has been here longer than I.

You are correct that it doesn't refer to rationalism vs empiricism - we tend toward the empiricist side of that debate. It is not really a philosophical position - more of an aspiration.

For me, rationalism corresponds to what I call "correct reasoning". Correct reasoning is any reasoning you would eventually perform if your beliefs were continually and informatively checked against your observations, starting from a belief set of arbitrarily large wrongness.

For example, if you believed that you should observe {X} as a result of employing reasoning mechanism {Y}, and you happened to get good tests of {Y} (i.e., highest possible surprisal value, -log p({X}|{Y}) ), forcing you to use a different {Y} until you found a {Y} that correctly predicted {X}, then the reasoning mechanism in {Y} is what I count as "correct reasoning".

Starting with this general principle, one can derive several heuristics to use when forming useful models of the world, and these form the ontology assumed by CLIP (the Clippy Language Interface Protocol).