I try not to open my mouth unless I'm reasonably sure I'm right. That doesn't guarantee new information won't prove me wrong but I start from the point of my own convictions and research.
As usually happens when an idea or thesis is presented, someone believes differently based on their research and experience.
Awesome! and the dialogue can begin. But how do you handle it when you've got to convince someone to see matters your way?
The surest way to persuade someone to listen to your point of view is to first show them you care about theirs.
Most folks are not as hung up about being "right" as they need to feel heard. That goes beyond listening, nodding and then jumping in with your perspective on where their logic fails. Many folks will concede a point if you first show you've understood it before you replace it.
Go beyond listening - passively standing there waiting for your turn to speak - to hearing what the other person is saying. Ask for clarification. Repeat a salient point. Summarize. Get their agreement that what you are echoing back to them is, in fact, what they are trying to say. Thank them for thoughtful research, brave ideas, candidness, etc.
Then ask if you can offer a different perspective.
This sounds easy but is actually hard. The more rushed we are, the less time we spend listening.
Actually, it is the most effective way I have found to connect with my family - especially my brothers! I've known they're often wrong since the day they first invaded my playroom. We have better conversations about contentious issues when I hear what they're saying before I tell them how off the mark they might be.
You might know you are right; others believe that they are. Persuading someone to see a different view is about collaborating before pronouncing the final verdict.