Anytime a people start grouping into a community for mutual protection and support, they invent a moral code.
People are pretty intelligent creatures. It does not take long for a thinking individual to come up with a set of laws which will make living together a lot more peaceable. Basically those rules always boil down to the golden rule. "Do unto other members of your tribe as you would have those other members do unto you. Any person or object not of the tribe is fair game."
Thousands of tribes through history and prehistory had never heard of the God of Abraham, yet those tribes developed moral codes and a system of jurisprudence.
A man alone has no ethics. A man alone is a predator, pure and simple. Morals/ethics come from the community's sense of self preservation, as a means to protect the community from that man alone.
People who choose to brew up their own storms bitch loudest about the rain.
