Two people sit opposed to each other. In between them is a cup:
One person argues: the handle is on the left. The other argues: the handle is on the right. Even when talking about a cup there can be disagreement.
Disagreement often rises from different points of view. Only when two people share the same point of view we could establish if one of them is wrong.
This reminds me of the story of the Blind men and an elephant, they all touch the same elephant but claim different qualities. One feels its tusk and says it’s like spear, another touches its legs and says it’s like a tree trunk.
This alludes to the many possible perspectives that are available to look at the exact same thing. Every perspective though is true but partial.
Integral theory (Ken Wilber) makes the attempt to create a framework which incorporates different perspectives. Someone can be looking at an idea from the inside (subjective), another person could be looking from the outside (objective) – who is right? They both could be to a certain extent.
So when two people disagree, it does not necessarily mean that at least one person has to be wrong – both can be right at the same time.