Wow! The Crossroads is a hotbed of vehement cartographers! Wunnerful.

What this really speaks to is, IMHO, the wide catalog available to us of ways to know. How you treat proposed information from the world, how you filter events to turn them into perceptions, what you include and what you leave out, and what you deem significant and why, is the real study involved. You can call them "proven conclusions" or you can call them "beliefs" -- any "certainty" always looks different to those who don't share it. Personally, I like to cleave to what is "workable", a sort of engineering criterion. But I have found that even that can be tricky, as the full system-wide ramifications of a "workable" solution or action sometimes turn out to be quite undesireable!

A