**This is the second in a series of responses to Oona Hathaway and Scott J Shapiro's recent article, Outcasting, which appeared in the November issue of YLJ. For Joshua Kleinfeld's response, see here.**

This Essay argues that we have been undergoing a profound sociocultural transformation over the last several centuries, which relates to the emergence of international law. This transformation is every bit as fundamental as those we once went through when transitioning from hunter-gatherer forms of life (which did not yet have legal systems or engage a distinctive sense of legal obligation) to more sedentary forms of agricultural life (with larger population densities, incipient domestic legal institutions, and—ultimately—an emergent distinction between morality and law). The primary mechanism that has been supporting this transformation is “outcasting”—as Oona Hathaway and Scott Shapiro have recently defined the term in their Yale Law Journal article of the same name. This Essay argues that outcasting provides the evolutionary stability conditions for a distinctive and emergent sense of international legal obligation in us. This shared sense of obligation is one of the basic preconditions for a genuine de facto system of international law—a fact that has important normative implications for how to evaluate international law.

In view of the billions of dollars and enormous effort that might otherwise be wasted, the public interest will be best served if the Supreme Court of the United States reaches the merits of the present challenges to the Patient Protection and Affordable Care Act (ACA) during its October 2011 Term. Potentially standing in the way, however, is the federal Tax Anti-Injunction Act (TAIA), which bars any “suit for the purpose of restraining the assessment or collection of any tax.” The dispute to date has mostly turned on the fraught and complex question of whether the ACA’s exaction for being uninsured qualifies as a “tax” for purposes of the TAIA. We argue that the Supreme Court need not resolve this issue because the TAIA does not apply for a distinct reason: the present challenges to the ACA do not have “the purpose” of restraining tax assessment or collection. In order for the TAIA not to bar refund suits, the TAIA must be read to bar suits with the immediate purpose of restraining tax assessment or collection. The present challenges do not have such an immediate purpose because the very authority to assess or collect will not exist until long after the litigation is concluded. Among other virtues, this resolution of the TAIA question does not predetermine whether the tax power justifies the minimum coverage provision.