Actually, re 'beliefs define reality', Planescape seemed to handle this a lot better than 3e's take on 9-sided Alignment, which manages to contradict itself several times in the PHB alone. It doesn't help that 1e Gygaxian lapsed-Midwest-Catholic morality is incompatible with 3e WoTC-Seattle-liberal morality. I've now given up on it and have reduced Alignment back to just Law-Neutral-Chaos, with early-Moorcockian definitions (similar to OD&D) so that eg the Nazis are Chaotic, not Lawful.