Principles are ways of successfully dealing with reality to get what you want out of life.
Ray Dalio, one of the world’s most successful investors and entrepreneurs, cites principles as his key to success.
Being effective at thoughtful disagreement requires one to be openminded (seeing things through the other's eyes) and assertive (communicating clearly how things look through your eyes) and to flexibly process this information to create learning and adaptation.
I have found that most people have problems being assertive and open-minded at the same time. Typically they are more inclined to be assertive than open-minded (because it's easier to convey how they see things than to understand how others do, and also because people tend to have ego attachments to being right) though some people are too willing to accept others' views at the expense of their own. It's important to remind people that they have to do both--and to remember that decision making is a two-step process in which one has to take in information as well as decide. It also helps to remind people that those who change their minds are the biggest winners because they learned something, whereas those who stubbornly refuse to see the truth are losers. With practice, training, and constant reinforcement, anyone can get good at this.