Think about a disagreement you've recently had with someone.
One that you felt quite strongly about... Why did you
disagree? Why did you feel so strongly about it? You've
just identified your perspective on that situation.
Whenever you disagree with someone, it's because you have a different perspective from them. And it's usually about how important a thing, activity or situation is, what it's meaning or purpose is. In other words, you decide what's inside or outside the system depending on what you feel is relevant or of interest to you about it.