Five Rules to Govern Any Society

If you could only pick five, what would they be?

I did not sleep well last night. My brain was obviously playing around with a question, because I kept waking up looking for answers. At first the question was,

If I could only come up with one rule for a society, what would it be?

Note that this would not be a rule for all the different ways in which people should treat each other. Be nice. (But to what …