Western religions have rules. And Western religions, as a rule, have two levels of rules.
One level is scripture. If you aren't a liberal, this level always was inarguable. But in general, scripture itself doesn't give enough; it is necessary to add at least one layer of interpretation. Here I'm not so much interested in doctrine, but in praxis.
In Judaism, you get midrash and other things argued out by rabbis. In Christianity, if you're in an episcopal-polity church, you get canons and other forms of tradition.
Church canons bring out the Junior Lawyer in people, particularly the kind of people who spend a lot of time on-line. They particularly get the "church tradition is immutable!" people going, because they offer a great opportunity for Defending The Faith in a really hard-nosed and impersonal manner. Best of all, in Orthodoxy (and often in Catholicism) you don't even really have to know them all that well, because the volume of them and the obscurity of many means that it's hard for people to check up on you.
That brings us to the Seeing Eye Dog Controversy....