For those who don’t know, Reconstructionist Polytheism is a category of Polytheism which strives to recreate pre-Christian religions as closely as possible, based on surviving information regarding beliefs, religious practices, and social customs. Reconstructionist Polytheists tend to maintain that their form of religion and all its subsequent beliefs and practices are more “true” and “valid” than other types of Polytheism, because Reconstructionist Polytheism adheres most closely to tradition.
ARGUMENT — Simply because a belief or practice is established as “traditional”/”historical” does not mean it is also ethically valid and permissible. Belief may be genuine, in that the believer is certain of his/her own convictions, and these convictions may have historical precedent, but the convictions themselves may not be objectively, ethically permissible and valid.
EXAMPLE — Many cultures, pre-Monotheist and Monotheist alike, have engaged in the practice of slavery. Slavery is an institution thousands of years old. “Underground” slave-trades still exist today. Does the age and establishment of slavery make slavery objectively, ethically permissible and valid?
For the sake of argument, we accept that all human beings have equal access to a set standard of “human rights,” and have free will. Slavery violates the rights and free will all human beings possess and are entitled to. If a religion or society professes to be free and equal (Just), and consents to the existence of the individual free will of every human being, it cannot ethically engage in the enslavement of other human beings, regardless of who those human beings are.
This, of course, begs the question as to whether or not “human rights” are in fact “Just,” and what “Just” actually means. But if “human rights” are in fact “Just” and coincide with “True Justice” (going by the premise of the “external ethic”), slavery is incompatible. If slavery is incompatible with what is objectively “Just,” slavery is not ethically permissible and is not valid.