The goal of this paper is to show the basis of justice considerations that flow from the concept of the person of John Rawls' political theory, its limits and possibilities. To do so I will start by detailing justice as fairness' construction procedure to then show how the main aspects of its concept of persons derive from it. Later I will list the main characteristics of such a concept, showing how the complete idea of citizenship to Rawls is more complex that it at first appears, although the requisites to the attribution of rights to an individual are very few. Finally, I will argue, although it defends values that we should not easily give up, it is still a inadequate basis for justice. That is so because, by insisting in a vindication of the considerations of justice founded in individual rationality, it deny them to the groups who do not have it, what makes it blind in the theoretical level and, unable to provide an effective protection of such groups in the practical one.