1. Marriage has not been a static institution for 1000s of years. Read a book on the topic if you don't believe me. I would recommend Marilyn Yalom's _A History of the Wife_. 2. There are lots of traditions that we change because they are incompatible with civil liberties. For example, there is a long, many thousand year old tradition of denying the full personhood of women. But we have tried to change that, why? Because just because something is a tradition doesn't make it good.