If we are take non-contradiction seriously than any moral statement should work like the "golden rule." If I say, "criminals should be prosecuted to the fullest extent of the law" it would be hypocritical of me to ask for a reduced sentence. I would in effect be saying, "this should be applied to everyone else but not me" and that is a contradiction. For certain things it would unreasonable for nearly everyone to be contradictory and therefore we could perhaps find a universal moral code for some things. For example, we might say, "is it ever right to kill yourself?" The person contemplating suicide would have to ask themselves whether it would be right for everyone in the world to kill themselves, if it wouldn't then they would contradicting themselves by saying, "it would be morally acceptable for me to kill myself."