Abstract: Many social practices treat citizens with cognitive disabilities differently from their nondisabled peers. Does John Rawls's theory of justice imply that we have different duties of justice to citizens whenever they are labeled with cognitive disabilities? Some theorists have claimed that the needs of the cognitively disabled do not raise issues of justice for Rawls. I claim that it is premature to reject Rawlsian contractualism. Rawlsians should regard all citizens as moral persons provided they have the potential for developing the two moral powers. I claim that every citizen requires specific Enabling Conditions to develop and exercise the two moral powers. Structuring basic social institutions to deny some citizens the Enabling Conditions is unjust because it blocks their developmental pathways toward becoming fully cooperating members of society. Hence, we have a duty of justice to provide citizens labeled with cognitive disabilities with the Enabling Conditions they require until they become fully cooperating members of society.