Theorizing about justice, equality and fairness has engaged moral and political philosophers for over two millennia. For Plato (1987), justice is a virtue which brings harmony both to the soul and to the state. Aristotle (1984) distinguishes commutative and distributive justice, according to whether it is a matter of punishments and compensation, or with proportional equality in the assignment of social benefits. For Aquinas (2006, II-II, 58, 1) it is justice which makes one render to another his due by a perpetual constant will, while Hobbes (1947) sees justice as strictly limited to the performance of valid covenants. David Hume deems justice to be an ‘artificial’ virtue that arises from convention for the common interest, to settle disputes between individuals fighting for resources in conditions of moderate scarcity (Hume, 1975,§257, p. 306). His contemporary, Adam Smith, defines justice as a minimal virtue, ‘of which the observance is not left to the freedom of our own wills, which may be extorted by force, and of which the violation exposes to resentment, and consequently to punishment’ (Smith, 1982, II.II.i.5, p. 79). Kant understands duties of justice as a subset of perfect duties toward others (prescribing or prohibiting certain specific actions always, with no exceptions), which can be legally enforced and the aim of which is to protect freedom (Kant, 1991, pp. 213 and 219). More flexibly, for John Stuart Mill, ‘justice is a name for certain moral requirements, which, regarded collectively, stand higher in the scale of social utility, and are therefore of more paramount obligation, than any others’ (Mill, 1991, p. 200). Following Marx in his rejection of justice as a bourgeois concept reinforcing inequality, Friedrich Engels discards it as a ‘social phlogiston’, a non-existent entity (Engels and Marx, 1973).