'“I believe specific things … and so I insist that you must do or not do specific things dictated by my beliefs “ — That’s the problem right there, this is the line they have crossed.'

I've been thinking lately that there is a problem with this stance (that a line has been crossed). Consider this: it is 1855 and an abolitionist says, "I believe that slavery is wrong, and so I insist that you must not own slaves." Would we consider this crossing a line? Many Southerners did because their economy was based upon slavery.

Personally I find the stance against slavery to be correct, but how do we distinguish this from other stances with which we disagree? I don't think it is as simple as declaring that all attempts to force people to abide by other people's beliefs can be dismissed as being wrong. I think other justifications must be offered.