Has the Law been made successively stricter through history? It seems that, prior to Moses, incest was acceptable (though, to my knowledge, not commanded). After Moses, incest became unlawful; but it seems that polygamy was still permitted (though again, I would argue, not commanded). By the New Covenant, though, polygamy (and, arguably, divorce) are both forbidden. Is this the case, or am I missing something? Thanks in advance.