The learner and teacher are constituted by social, political, and economic
bounds, and yet the twenty-first century polis is increasingly a world
without boundaries. This is a perilous and exciting time to teach and learn.
As agents of terror have shown, political boundaries are uncomfortably
permeable. Economically, culturally, and religiously, globalization has
reduced the power of nation-states and threatened erasure of their
boundaries. Isolated identities—nationalistic, religious, linguistic, sexual—
are under siege. Nothing is immune from alteration by these large-scale
forces. Plato’s insight is that the pressures and possibilities, which determine
the larger context of life, reside in a condensed form in the classroom.