We have moralistic statements from the pre-modern period against slavery, against territorial expansion, against war of aggression, against outcasting, against imposing will and culture upon others, etc. We also have moralistic statements for all these things from the same time. We can say that people knew better than to do all these things, and that they didn't. It's not so easy to determine what code an individual followed by, and even if we are able to determine the code, what will our judgement be aimed at? Their success or failure to follow the code? The fact that they were subject to the right or wrong code? And where do we take the authority for such a judgement from?