And as to the spirit of party, which unhappily prevails amongst mankind, whatever are the distinctions which serve for a supply to it, some or other of which have obtained in all ages and countries; one who is thus friendly to his kind, will immediately make due allowances for it, as what cannot but be amongst such creatures as men, in such a world as this. And as wrath and fury and overbearing upon these occasions proceed, as I may speak, from men's feeling only on their own side; so a common feeling, for others as well as for ourselves, would render us sensible to this truth, which it is strange can have so little influence; that we ourselves differ from others, just as much as they do from us. I put the matter in this way, because it can scarce be expected that the generality of men should see, that those things which are made the occasions of dissension and fomenting the party spirit, are really nothing at all: but it may be expected from all people, how much soever they are in earnest about their respective peculiarities, that humanity, and common good will to their fellow creatures, should moderate and restrain that wretched spirit.
Joseph Butler, Fifteen Sermons, Sermon XII. It is indeed a little strange how we so often tend to treat disagreement as asymmetrical, when in reality we differ from others as much as they differ from us. It doesn't follow, of course, that the disagreement is insignificant; but it does show a way in which it is silly to be annoyed merely at the disagreement.