Why do civilization have laws?

I think civilization have laws to make the everyhing in control and to make people do the right things. However if the people don't follow them, there will be a problem so there are laws that we have to follow. I learned some laws and punishments which were made by Hammurabi and one of it was 'If a son strikes his father, his arm shall be cut off.' This one was given by Mr.McQueen and he told us to write on a postit if we agree or disagree. I chose both of them because first you can't hit your own father and that is like changing places so the son would be the father and the father wouldbe the son. You can't change that so this is expaination of why I agreed. I disagree also because if the father cut off his son, the son can't help his father when he is sick and needs help. We also some questions that were at the back of the paper. One of the questions was Why do you feel your punishments are appropriate? and I said I think my punishments are appropriate because it has my thoughts in it and it is not too harsh, it is just right for me.