Interested in improving your reasoning and decision-making skills? Then Less Wrong is for you. Less Wrong is a large, active website for people who try to think rationally.
A series on the use and abuse of words.
An introductory essay on rationality by Eliezer Yudkowsky.
Ethical injunctions are rules not to do something even when you believe it's the right thing to do.
A sequence on the ultra-high-level penultimate technique of rationality: How to actually change your mind.
A community blog devoted to refining the art of human rationality.
The first introductory sequence. A collection of posts dealing with the fundamentals of rationality.
What words like "right" and "should" mean; how to integrate moral concepts into a naturalistic universe.
The second introductory and first major sequence. How to see through the disguises of answers or beliefs or statements, that don't answer or say or mean anything.
How to take reality apart into pieces...