Sorry, seems like you're either in over your head here or misunderstood what I said. Both deontology, utilitarianism and all other major schools of ethics* are

Sorry, seems like you're either in over your head here or misunderstood what I said. Both deontology, utilitarianism and all other major schools of ethics* are justified a priori. This is common, introductory, knowledge in philosophy. Virtually nobody considers ethics an empirical science. That being said, descriptive and experimental ethics have made tiny inroads very recently. * It doesn't really work like that today anyway; it's a decision tree of "schools."