By ‘peoples’, Rawls means “the actors in the Society of Peoples, just as citizens are the actors in domestic society” (L.P. p.23). Peoples share three features: a common system of government; what J.S. Mill called ‘common sympathies’ (XVI of Mill’s Considerations, 1862); and a moral nature. Although the Law of Peoples is supposed to be part of liberal foreign policy, the peoples Rawls talks about are not necessarily liberal. 'Decent hierarchical peoples' also feature as parties to the Law of Peoples, though burdened states, outlaw states and benevolent absolutisms do not. The inclusion of 'decent hierarchical peoples' is demanded by the notion of toleration: a notion Rawls sees as integral to liberalism. In part, the Law of Peoples is an attempt to show how far international toleration by liberal societies can reasonably be expected to extend.
By 'Law of Peoples’, Rawls means “a particular political conception of right and justice that applies to the principles and norms of international law and practice” (L.P. p.3). This political conception of justice is arrived at through the device of the 'original position' – a hypothetical arrangement whereby representatives of each of the peoples get together with the aim of determining principles that will govern the terms of their association. The principles yielded by this process make up the content of the Law of Peoples. The eight principles are:
The content-giving part of Rawls' thesis belongs to Ideal Theory, i.e., it is not supposed to reflect anything that has actually happened in the world. Nevertheless, it provides us with an (ideal) goal in international relations that can inform and give direction to our (non-ideal) foreign policy. Rawls refers to this ideal conception as a “realistic utopia”: realistic because it could and may exist; utopian because it “joins reasonableness and justice with conditions enabling citizens to realize their fundamental interests” (L.P. p.7). This is a continuation of Rousseau’s idea that any attempt to discover sure principles of government must take “men as they are and laws as they might be” (The Social Contract; opening passage). Thus, the Law of Peoples is realistically utopian: it is an attempt to show “how reasonable citizens and peoples might live peacefully in a just world” (L.P., Preface, p.vi).