We cannot discuss international law and its possible evolution towards a new international law of development without briefly reminding ourselves of what law is and how it emerges. What makes law, in other words? Law, a legal system, first of all presupposes a community. In the international case this is a community of autonomous states. Next—to achieve an effective system—there must be consensus on both the means and the ends of regulation of relations within that community or an authority with power to execute the rules of that system. At the end of the day the international community has depended, and continues to depend, on a blend of consensus and authority. Next, there must be structure, an organised network of institutions for the determination of rules (“sources”), for the resolution of conflicts and for the carrying into effect of decisions on those rules and conflicts. Thus law cannot exist without purpose; the law embodies goals which may be limited or extensive in their reach—the law is for something, some end. Lastly, of course, there must be rules which specify how the system is to work, and the actual content of the relations prescribed. In the evolution which we have witnessed since the Second World War international law has moved in all these respects; and this movement is quite vital for the theme of international law and development.