(A little more on a theory of knowledge.) Some basic ideas of General Semantics are the map not being the territory, words being abstractions, and a dynamism when regarding truths (something called time-binding that humans are able to do, understand that we fit into a progression, "We can see our own organizations, our society as a whole, as in a stage of development"). Some more definitions of General Semantics reveals it to be a neo logical positivism -- and in terms of the theory of knowledge, it fits well with Popper.
As if to close more loops the Non-allness property of words in this theory means my comments about E-Prime driving closer to the is-ness seem pretty spot on. And Clay Shirky's pointer towards the world being divided between dynamists and statists is deeper than I first though: dynamists accept our ability to time-bind and, delving into Popper again, live with a time-evolving cultural knowledge. Statists don't. Fascinating.
Now I know (is that knowledge in World Two? Or Three?) that if you read my posts at the end of today, Monday, it'll look like I've been exploring just the one topic. But actually E-Prime and Popper, oh and the Long Now, all started independently, to be brought together just now. Synchronicitously.