This important volume examines the phenomena of cognition from an adaptive perspective. Rather than adhering to the typical practice in cognitive psychology of trying to predict behavior from a model of cognitive mechanisms, this book develops a number of models that successfully predict behavior from the structure of the environment to which cognition is adapted. The methodology -- called rational analysis -- involves specifying the information-processing goals of the system, the structure of the environment, and the computational constraints on the system, allowing predictions about behavior to be made by determining what behavior would be optimal under these assumptions. The Adaptive Character of Thoughtapplies this methodology in great detail to four cognitive phenomena: memory, categorization, causal inference, and problem solving.