Come to think of it, why can't ANYTHING be legal and allowable? After all, somewhere in the world is someone who wants to do something - let it ALL be legal. No rules at all, ever - isn't that what every 12 year old would like?
That depends... It could be the perfect libertarian state or total anarchy.
The problems arise when your rights impede on my rights.
How do we decide those issues?
They are both one in the same.
Selfishness is thine name, Liberaltarian.
It would be total anarchy, leading to totalitarianism. No doubt about it.
How do we decide what is legal/illegal?
There are moral absolutes, universal to every monotheist religion (and some that aren't, like Buddhism) since the dawn of history. That's a start. Blackwell allowed that the 10 Commandments are the foundation of laws, at least in the western legal tradition.
People like to spout "you can't legislate morality" as though it meant something. All laws are legislating morality. Usually people who recite that mean there should be no laws impinging on sex acts. But society has a strong interest in controlling sexual behavior, which is a long topic in itself.
The only way a society could exist without laws would be if every citizen were a living saint.
Ha ha.