The Greeks were taken over by the Romans. The Romans too many of the Greek gods and renamed them. Every god needs a story, right? The Romans took the Greek stories and made them their own.
The general thinking is that a law is unjust if it doesn't square with natural law. This is certainly the view that was put forth in Martin Luther King's Letter from Birmingham Jail.
So, a law that was passed that treated people differently wouldn't square with the natural law that all humans are equal. And thus, one would have the obligation to disobey that law.
A monster like Grendel is an antagonist from Beowulf. A hero must be courageous and kindhearted to be able to defeat a monster like him. One must also trust his or her own instinct. The calmness of the hero defeated Grendel who is filled with anger.
