Fortunately, most things don't fall into that nebulous category. In fact, if someone in a discussion is trying to shove something into that "who knows what's true or not" category, the proper response is skepticism. Don't discard common sense either. It's your brain working things out before you have a chance to tell it that Heisenberg means nothing is certain.

In short, you don't need to get philosophical to declare confidently that an elephant has more mass than a hummingbird, and a surprising number of answers are that obvious.

Nowadays, "sufficient data" is a lot easier to come by, and I can find most answers in a short time on the internet (and no, not from Fox News or CNN) that would have taken a day or two in several libraries not that long ago.