Law and order is necessary for a free society. In the 1960s, Jane Goodall was horrified to discover that her beloved chimps of Gombe were carrying out a genocidal war. We have known for many years the main cause of death of adult men in hunter-gatherer societies. When agriculture allowed for the building of villages, we find the first evidence of ancient massacres. The very first chapter of the Iliad deals with the rage of Achilles when Agamemnon took his captive girl, Briseis, from him. War is older than humanity. Violence is an essential part of human nature.
Left to our own devices, humans are selfish, aggressive creatures. We are constantly seeking our own advantage. How then are we to be protected from ourselves and each other?