Belief.

Seth Godin has a great post on judgment. His argument is that having perspective of a person's beliefs can help you deal effectively with conflict. He aims to explain a marketing position, but I think it translates just as well to personal relationships.

He says:

If I believed what you believe, I'd probably be acting exactly the same way you are right now.

Our beliefs, at their core, are really just dispositions to seeing something a certain way. If we better understand what other people believe, right or wrong, we have a chance to "put ourselves in their shoes."

Why is this perspective important? Seth goes on to say:

If I can help change what you believe, I bet I can change your actions as well.

We want our relationships to work. So, when conflicts arise -- generally always related to someone's belief about some thing -- our best interest is to alter a belief (in ourself, or the other person).

By putting ourselves in their position, we have a much greater chance of remaining patient, understanding the overall situation, and eventually effectively reaching our desired conclusion.