the belief that there is an absolute 'right' position, and that those who hold it are obligated to bring those that do not hold it either 'into line' or 'into the light', depending on whether they intend to convert everyone by force or by example.

it is the nature of being human to react to differences, and at the most extreme level our reaction is to eliminate the 'other', that's why human history is littered with violence and hate. it is only culturally (and even then, only true of some cultures, at some points in history) that we try to work against this basic drive (and perhaps it is wanting to do so that makes us unlike other living things)

however, 'culture' is a new and artificial construction, relatively speaking, and we can't even agree on what this cultural standard is; all we've achieved so far is to create a whole new range of things to measure 'difference' by.

one view is 'accommodation' of the other, but, as i say, that goes against a deep human instinct.
the other view is 'isolation' from the other, but that only kicks the inviable conflict down the road

but, there is hope.

one day you die and it all goes away.