Critical-thinking skills are crucial for social life, especially for those in academic and professional disciplines. For this reason these skills are indispensable for undergraduate studies as a foundation for future work. The critical thinker brings reasoned and analytical skills to his or her endeavours. Moreover, acquiring habits of mind such as being fair and just, open-minded, and so on, he or she is oriented towards the goal of being a reasonable person.This Unit is intended to provide a basic understanding and training of critical thinking to students. It starts with (1) a reflection on critical thinking itself (in order to remove relevant misunderstandings and to raise students’ awareness of its importance). This is followed by (2), an introduction of the elementary subject matters of informal logic (including how to attain clarity in language use, how to identify, analyze, construct, and evaluate arguments, etc.), and (3), a discussion of the central barrier of critical thinking, namely, biases. Our introduction of the generic critical thinking skills will be further extended to cover topics which include, moral reasoning, problem-solving, decision-making, metaphorical thinking, and creative thinking.