Survival of the Fittest
Safety in Numbers
Hunting in Packs
Fights for the Right to Lead
Territorial Warfare
Borders
Social Structure
Ownership
Us versus Them
Hereditary
Fight for the Right to Rule
Nobility
Laws
What is Law?
It is a tool of a sovereign govt to enforce order. To avoid disorder, the govt will pander to what is socially acceptable & what is not. Social acceptance is usually conceptualised as morality.
Once, not so long ago, it was socially acceptable to not allow women to go out of the house; socially acceptable to have slaves; acceptable to treat children as chattel.
Once, not so long ago, it was socially unacceptable for peasants to own land; socially unacceptable for women to work; unacceptable to commit adultery; or to be homosexual.
But society changes; attitudes change; acceptability changes. For most of the modern world, the big change in attitude was during WWII when men were at war; then women had to work in factories; youth had to be conscripted to join the military to die for their country. We sometimes think of this as liberalism... but it was basic survival...
Law and how it evolves is just another reflection of social acceptance. If Law does not evolve with society, it will fade away to a point where it only becomes relevant if it is enforced by the threat of violence. Same with Religion.
Religion needs to evolve with what is socially acceptable. If not, Religion too will fade away -or- exist only by threat of violence.
Governments often re-write Law (and Religion) to keep themselves in power. Threats of violence are quite normal for governments but there comes a point where society fights back. Evolve or be replaced.
Barter Trade
Money = Store of Value
Money = Medium of Exchange
Money = Value because I said so