The meaning relevant in this case is generally the community surrounding the LessWrong website and associated other communities (not necessarily exclusive to th

The meaning relevant in this case is generally the community surrounding the LessWrong website and associated other communities (not necessarily exclusive to those who have actually used the website LessWrong though.) (There's also a different older meaning in philosophy which is largely unrelated) a (joke) inductive definition: base case: Elizier Yudkowsky is a rationalist. inductive case: Anyone who frequently argues with rationalists is a rationalist. The community speaks a fair bit about how to deal with psychological bias, and also talks about Bayesian reasoning, decision theory, etc. Also talks about what conversational norms are helpful in facilitating productive discussion especially in the presence of disagreement, etc. There are also those who would be called "rationalist-adjacent" who, well, people who are socially-near "rationalists", but, fairly similar topics discussed. There have been some attempts to use the phrase "aspiring rationalist" rather than "rationalist", and to reserve the term "rationalist" to refer to hypothetical idealized practitioners of the ideas. Also, sometimes people shorten "rationalist" to "rat".