 To explain the distinctiveness of justice, Mill suggests that it designates moral requirements that, because of their very great importance to human well-being, people have a right to have discharged, and are therefore matters of perfect obligation. A person who commits an injustice is always liable to punishment of some kind, he argues. So he explains our sense of justice in terms of the resentment we feel towards someone who breaches these requirements. Sidgwick, who laid greater stress than Mill on the connection between justice and law, also underlined the relationship between justice and gratitude, on one side, and resentment, on the other, in order to capture the way in which our concern for justice seems to differ from our concern for utility in general.