As I already mentioned, one difficulty in assessing Hart’s analysis of justice as equality in
interpersonal allocation is that he fails to do much by way of identifying, let alone motivating,any competitor analysis. However, the more than two thousand year interlude betweenAristotle and Sidgwick discloses a salient rival. This is a view of justice encapsulated in what
might be called Justinian’s maxim. In Justinian’s
Digest,
it is affirmed that ‘justice is a
c
onstant and unceasing determination to render everyone his due’ [‘ius suum’].
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Of course,
what counts as each person’s ‘due’ is open to radically different formulations, but according
to one powerfully formative tradition, it refers to that to which each person has a (moral)right. The basic idea is that some moral obligations are perfect and others imperfect. Perfectobligations are owed to some ascertainable individual, the right-holder, whereas imperfectobligations have no counterpart rights. Hence, we can differentiate duties of justice, which
are owed to people as a matter of right from, say, reasons, or even duties, of charity, which arenot owed to anyone in particular.