This article suggests that philosophy courses could play a key role in teacher education courses as a means of developing the critical thinking skills teachers need in the 21st-century classroom. The authors focus on: (1) Shifts in Education Standards; (2) The Value of Philosophy; and (3) Paths to Implementation. Five paths to implementation include: (1) Socrates and classroom discussion; (2) Descartes and skepticism; (3) Jean-Paul Sartre and inquiry; (4) John Dewey and experiential learning; and (5) Cornel West and civic engagement. The authors discuss how the ideas of ancient through contemporary philosophers can be applied to the different standards that dominate the pedagogical challenges faced by today's classroom teachers, and conclude that most teacher education programs are neglecting the "ancient paths" that lead to love of learning for learning's sake. They suggest that these very requirements have never been more necessary and practical for classroom teachers, and, in fact, they offer the skills that will give life to the kind of thinking teachers are working toward in the first place.