This chapter considers the relationship between tradition and change. Tradition and change are often thought to be antagonists, and there certainly is a tension between them. Nevertheless, both changes from within a tradition (endogenous change) and changes from outside it (exogenous change) depend upon adaptation in the tradition or selection of a new tradition in order to be effective. This chapter selects a few legal examples to illustrate these mechanics. As to exogenous change in particular, it chooses the issue of discrimination on the basis of race and the Supreme Court’s decision in Brown v. Board of Education, which is sometimes taken to be the paradigmatic challenge to tradition in constitutional law. It then explains the relationship between reason and tradition.