Social cooperation has always been an important concept in Rawls’s political philosophy. In A Theory of Justice he conceives of society as “a cooperative venture for mutual advantage,” whose members acknowledge “certain rules of conduct as binding,” rules that “specify a system of cooperation designed to advance the good of those taking part in it” (TJ 4). In his later writings, however, social cooperation becomes even more central. The “idea of a society as a fair system of social cooperation over time from one generation to the next,” he tells us, is the “most fundamental idea” in his conception of justice as fairness (JF 5). Indeed, it is even built into his conception of political philosophy, whose first task is to narrow “the divergence of philosophical and moral opinion at the root of divisive political differences” so that “social cooperation on a footing of mutual respect among citizens can still be maintained” (JF 2).

Social cooperation is best seen by contrast to “socially coordinated activity – for example, activity coordinated by orders issued by an absolute central authority” (JF 6). The key point is that all social life involves a division of social labor, not merely in the narrowly economic sense epitomized by Adam Smith’s pin factory, but in a broader sense of differentiated social roles, each with its own responsibilities and powers.