What makes society just?

The ruler in society is responsible for creating rules and regulations for society. Also I think the ruler is responsible for  society's rights, and how to make it's society happy and wealthy. The ruler has to just the society. I think people are not naturally born with good or bad. In my opinion, the government should control the taxes and economy. A society is just by law and equal rights, Everyone has to follow the law and that makes society just. Also equal rights are very important in ruling the society.