Since one of the major aim of A Theory of Justice was to argue for the stability of a well-ordered society, I this paper I discuss the importance of the sense of justice to achieve that stability. I analyse the interpretation of our moral psychology in order to show its importance in the justification of the principles of justice that would promote social stability. Such analysis allows me to conclude that the search for natural bases to found moral feelings constitutes for Rawls an alternative to any deductive and metaphysical justification of our social practices