This paper articulates and defends two theses due to Richard Paul and Linda Elder. First, creative thought and critical thought cannot be separated. Second, the intellectual traits constitutive of critical thinking are interdependent. The twin theses combined with certain impact studies show that study abroad enhances both creativity and criticality. The primary value of such gains resides in their potential to realize not only the Socratic ideal of rationality but also the Diogenean ideal of cosmopolitanism. The former consists in the cultivation of fair-minded, creative, and critical individuals and societies, whereas the latter consists in the cultivation of citizens of the world and the single community to which they belong. Since study abroad can lead to intellectual growth in participants, this paper recommends certain policies and practices to help ensure the desired gain.