Miller's Rule states that whenever a person is advocating a position that appears to be irrational, you should try to conceive of what reality would have to be in order for that position to be rational. By understanding the other person's reality, you can better determine whether or not perceptions can be changed and agreement reached.
A simlar quest can be taken when resolving problems or conflict. If person A is taking a position that seems to be irrational, rather than dismissing it as foolish or unrealistic, person B might explore (1) what would have to be done to that position to make it rational and workable and (2) is that change within our grasp?
That is how alliances are made between dreamers and pragmatists.