Critical thinking has long been a goal of social studies education, and its importance has been reiterated in documents delineating standards for the social studies. Yet, teaching critical thinking is problematic because there are competing definitions and practices and many barriers to its implementation (Wright 1995; Onosko 1989). In this article, the author briefly outlines several approaches to the teaching of critical thinking and develops more fully one recent approach that relies on the use of critical challenges.