This document provides definitions of critical thinking from Edward Glaser, Michael Scriven and Richard Paul, and Richard Paul and Linda Elder. It introduces the topic of critical thinking and asks students to reflect on what they know about it. Key points introduced include that critical thinking involves considering problems thoughtfully using logical reasoning methods, actively applying and evaluating information to guide beliefs and actions, and overcoming biases by imposing intellectual standards. Students are then asked to demonstrate their understanding through an exercise and reflection.