I just posted the following on a comment thread about gay marriage, in response to a couple of people who made the usual arguments about gay marriage leading to polygamy and incest and such. My response:
Suppose the slippery slope argument is true? What if gay marriage *does* lead to legalization of polygamy, incestuous marriage, and so forth?
So what?
If you don’t have a good reason to ban polygamy, then polygamy should be allowed. Likewise for incestuous marriage.
My point is that if there *are* good reasons to ban polygamy and incestuous marriage, those reasons will still exist regardless of what happens with gay marriage.
Think about it.