 To be stable principles of justice should be realizable in a feasible and enduring social world. They need to be practicably possible given the limitations of the human condition. Moreover, this feasible social world must be one that can endure over time, not by just any means, but by gaining the willing support of people who live in it. People should knowingly want to uphold and maintain society’s just institutions not just because they benefit from them, but on grounds of their sense of justice. In choosing principles of justice, the parties in the original position must take into account their “relative stability.” They have to consider the degree to which a conception (in comparison with other conceptions) describes an achievable and sustainable system of social cooperation, and whether the institutions and demands of such a society will attract people’s willing compliance and generally engage their sense of justice.