Is There a Universal Standard of Justice?

Slavery was almost uniquely an american phenomenon, as opposed to the institution that has existed in a great many civilizations. Why is it that we focus only on the grievance and not on something that we can all agree was a wonderful thing and that we should all be happy about? Well, because we can't celebrate anything good coming from the european population, only the bad. You had to have some kind of sense that there are some things you can't do to other people,. There's one universal standard of justice, which is an idea that europeans had been pushing for quite some time.