In Roper v. Simmons, the Court unequivocally affirms the use of comparative constitutionalism to interpret the Eighth Amendment. It does not, however, provide an obvious theoretical basis to justify the practice. This Article searches for a theory...

Constitutional comparativism—the notion that international and foreign material should be used to interpret the U.S. Constitution—is gaining currency. Yet proponents of this practice rarely offer a firm theoretical justification for the practice...