I learned a good way to stop—or prevent—arguments.
Did you ever notice it takes at least two people to argue? If someone tries to lure you into a fight simply refuse to participate. When you do not fight back the other person will at first feel very frustrated and maybe even angrier than before. And then they have to stop the fight because no one is fighting back.
The very valuable lesson in this method is to note all the things the angry person yells at you. Take mental notes of everything for which he blames you. What he reveals with his outburst is exactly what is really going on inside him.