Justice as mutual advantage and the vulnerable

Since at least as long ago as Plato's time, philosophers have considered the possibility that justice is at bottom a system of rules that members of society follow for mutual advantage. Some maintain that justice as mutual advantage is a fatally flawed theory of justice because it is too exclusive. Proponents of a Vulnerability Objection argue that justice as mutual advantage would deny the most vulnerable members of society any of the protections and other benefits of justice. I argue that the Vulnerability Objection presupposes that in a justice-as-mutual-advantage society only those who can and do contribute to the cooperative surplus of benefits that compliance with justice creates are owed any share of these benefits. I argue that justice as mutual advantage need not include such a Contribution Requirement. I show by example that a justice-as-mutual-advantage society can extend the benefits of justice to all its members, including the vulnerable who cannot contribute. I close by arguing that if one does not presuppose a Contribution Requirement, then a justice-as-mutual-advantage society might require its members to extend the benefits of justice to humans that some maintain are not persons (for example, embryos) and to certain nonhuman creatures. I conclude that the real problem for defenders of justice as mutual advantage is that this theory of justice threatens to be too inclusive.