Over the last several decades, science has developed a new picture of how we succeed or fail to seek true beliefs and achieve our goals. The heuristics and biases program in cognitive psychology has exposed dozens of major flaws in human reasoning, and along with them, insight into the mental processes that produce these flaws. Bayesian probability theory and decision theory have been used in increasingly powerful statistical methods and machine learning algorithms; I believe that they also provide a lens through which to view everyday life. Evolutionary psychology and social psychology are also telling us new and disturbing things about human nature – can we, now knowing, do any better?

The vast bulk of my writings on rationality are contained on the Less Wrong community blog – follow the link to see some of my recommended posts. Hopefully that corpus will be processed into wiki pages and e-books in the near future, followed by an introductory-level physical book – to be notified when (e-)books come out, follow the Subscribe link in the right-hand column.

Essays currently available:

Twelve Virtues of Rationality
The first virtue is curiosity. A burning itch to know is higher than a solemn vow to pursue truth. To feel the burning itch of curiosity requires both that you be ignorant, and that you desire to relinquish your ignorance.
Overcoming Bias
Cognitive Biases Potentially Affecting Judgment of Global Risks
Introduces the field of heuristics and biases (the experimental investigation of systematic human errors and what they reveal about human cognition) from the perspective of how known biases may throw off our reasoning about uncertain risks to the human species.
The Simple Truth
What is “truth”? It’s surprisingly simple.
An Intuitive Explanation of Bayes’ Theorem
Bayes’ Theorem for the curious and bewildered; an excruciatingly gentle introduction.
A Technical Explanation of Technical Explanation
More Bayes. Many of my other writings rely on this page.
(The Cartoon Guide to) Lob’s Theorem
Lob’s Theorem shows that Peano Arithmetic can never assert its own soundness. I prove this amazing theorem using the standard mathematical technique of cartooning.