how Aquinas and Aristotle account for justice in human law?

Answer 1

Thomas Aquinas, like many philosophers, tries not to build castles in the sand. So he instead looks for primary causes - a sound base upon which everything else is built. Whether he succeeds is the subject of much of the later discussion about him.

To Aquinas, all laws flow (of course) from God. There are seven basic virtues, one of which is justice, and these are derived from God and apply to all things. This is 'eternal' law, in that the rules, like their source, never changes.

Knowing these seven virtues are established by God, we can reason about how justice applies to our actions, and this is what Aquinas called 'natural law'. Beyond and derived from 'natural law' is 'human law', distinct because it is imposed by temporal authority, limited, and not necessarily naturally flowing from inclinations to do good.

Human law, because it is derived ultimately from eternal law, which includes the quality of justice, must also be just and seeking the greater good. The dictates of governments that do not fulfil these qualities are not appropriately termed 'laws' under Aquinas' system. He refers to 'unjust laws' as "acts of violence", and quotes Augustine who says, "An unjust law does not seem to be a law at all."

Aristotle tends to take a more definitional view (not unusual to him). Justice is not just -A- virtue (as Aquinas would later claim), but is actually ALL virtues. And the greatest justice is that which is performed on neighbors rather than the self.

Aristotle overtly points out that most human laws are really enacted to benefit those in power. Like Socrates, however, he believes that it is almost always to the benefit of people in power (and society as a whole) to promote virtue, so almost all laws end up being just ones on this basis.

Injustice creeps in when things are unequal. Yet Aristotle doesn't mean inequality in a democratic sense that everyone should get exactly the same, rather he is referring more that people get an amount equal to what they deserve - some more, some less.

So both Aquinas and Aristotle associate justice with virtue, but Aquinas views it as just part of the picture while Aristotle suggests that justice IS the picture. Aquinas declares that justice is important because God says it is, and the human law is really only present to help people live virtuously and suppress excess vice. Aristotle, on the other hand, sees justice as a goal to be sought after by self-interested governments, mostly because of the benefits a just system would reap.

Hope that helps! (Link 1 is an excellent summary of Aquinas, link 2 covers Aristotle but verges to the obscure at times).