I am fascinated by the relationship between law and metaphysics. Specifically, how is it possible that a law can be called "unjust"?
Three examples Andy, Chris, Cliff and I talked about.
First, the Nuremberg war crime trials. How is it possible for one sovereign nation to call into question the laws of another sovereign nation? What is the legal justification for a "crime against humanity"? That is to say, why were the Nuremberg verdicts morally "right" in a way that transcends the criticism that the winners get to write the history books? More simply, were the Nazis "wrong" simply because they lost? Who gets to decide when two nations disagree about some moral truth?
Second, Martin Luther King Jr's "Letter from Birmingham Jail" where King calls attention to the injustice of Jim Crow segregation laws. In the eyes of the law, King was a law-breaker. And yet, we consider King righteous even though he sat in jail. The criminal can be morally correct.
Lastly, the "Higher Law" and the American abolitionist movement. Slavery was enshrined in the US Constitution. And yet, the American abolitionists pointed to a "Higher Law" that stood above and called into question the moral integrity of the Constitution. The US Constitution was morally wrong.
There are many other examples, but these cases illustrate the main point. There exists some moral vantage "beyond" the law that creates an ability to level moral criticisms against current legal arrangements, both within nation states and between nation states. There exists a transcendent vision of justice that cannot be reduced to the sovereign fiats of nation states. Laws can be unjust. The founding documents of sovereign nations can be morally wrong. Victory or loss in war doesn't give you the right to determine what is or is not a crime against humanity.
In short, we all live with the understanding that there exists a metaphysics of justice that transcends the law.