Rationality: From AI to Zombies is a 2015 ebook by Eliezer Yudkowsky on human rationality and irrationality in cognitive science.
The ebook can be downloaded on a "pay-what-you-want" basis from intelligence.org or viewed on the website readthesequences.com It is an edited and reorganized version of the Sequences, a series of blog posts published to Less Wrong and Overcoming Bias between 2006 and 2009.
Rationality: From AI to Zombies serves as a long-form introduction to formative ideas behind Less Wrong, the Machine Intelligence Research Institute, the Center for Applied Rationality, and substantial parts of the effective altruism community.