Welcome, Christianity
“So in everything, do to others what you would have them do to you, for this sums up the Law and the Prophets.”
— Jesus of Nazareth, Matthew 7:12
Christianity states the Golden Rule in its active form: do good. The Ultimate Law states it in its passive form: do no harm. These are not contradictory — the passive form sets the floor that must never be broken, while the active form aspires to more. A Christian who follows "do no harm" has not abandoned Christ’s teaching; they have secured its foundation.
The Ultimate Law
Logic is the ultimate law.
Do not do to others what they would not want to be done to them, or you will be punished regardless of your will.
The purpose of punishment is to erase guilt, via retribution and restitution.
That is the entire law; it cannot be changed, all the rest is commentary.