Only recently have world global institutions, like the United Nations Security Council, assumed the role of world legislator. The past few decades, however, have witnessed the appearance of grand normative theories of global law, the most significant recent example being John Rawls's The Law of Peoples (1999), in which Rawls applies many of the same (or similar) abstract, universalizable concepts that are found in his earlier works on political theory to global law and presents an "ideal theory" for a "Society of Peoples". Although I do not oppose full-blown theorizing about international lawmaking, I contend that a middle-range approach is a useful complement to a broad-range approach because of the incipient character of global law, and I further argue that Cicero's ius gentium, the law of nations, provides the basis for such a mid-range approach. Since ius gentium is connected to domestic law and values, it can accommodate the practical necessities of today's world legislation, i.e., necessities resulting from the absence of extensive, long-standing global legal norms and of international institutions to enforce world legislation. Ciceronian ius gentium, however, is not confined to domestic law. The link between Cicero's "law of nations" and his "natural law" points to the possibilities of a more progressive legal future, not yet realized.