How do you know that?

That's one of the best questions you can ever ask another person. It get's right to the heart of the matter. It's also a question we need to be regularly asking ourself. Think of it as self calibration, and don't be alarmed if doing this throws up the occasional shock. To be honest, my life would have been very different had I applied these checks and balances consistently.  Not that I have many regrets, and in fact being wrong about one thing  in particular actually produced a vast quantity of good as a result.  But anyway, during this journey of ours we might sometimes hear somebody saying words to the effect of "I just know". Now for all I can tell they might be right, but by and large if people cannot give you a plausible explanation for something, you might want to reflect whether you should incorporate it into your cannon of knowledge. This of course leads to the next quandary; how do we figure out a good claim from a bad claim? Well the amount of work you put in probably needs to be proportionate to the gravity of the question. If it's something trivial then give it some slack, cos' there's no point in being obsessive. But for the bigger decisions, the one's that inform large swathes of your life, I'd suggest you need to put some additional mileage in. Is what that person says true? How do they know? Where did the knowledge come from? These are all useful considerations. One final idea, and I freely confess that this won't be for everyone, is that you actively seek out alternative opinions. I mean, if a good idea is a genuinely good idea it should be able to stand up to cross examination? And if not why not? Smell I rat? Perhaps that claim isn't such a good one? If that's the case then perhaps that's the  moment  when you nod politely and move the conversation onto pastures new.