The lowest hanging fruit in this regard is probably vocabulary that divides thingspace into more natural categories. See the whole Human's Guide to Words Sequence for more details.
Thanks, I'll spend some time groking these, but I have a feeling these won't quite dissolve my main concern, whether it's simply a confusion or a genuine issue. I'll try to more clearly state my question in some of the other comment threads.
Rationality requires intelligence, and the kind of intelligence that we use (for communication, progress, FAI, etc.) runs on language.
It seems that the place we should start is optimizing language for intelligence and rationality. One of SIAI's proposals includes using Lojban to interface between humans and an FAI. And of course, I should hope the programming language used to build a FAI would be "rational". But it would seem to me that the human-generated priors, correct epistemic rationality, decision theory, metaethics, etc. all depend on using a language that sufficiently rigorously maps to our territory.
Are "naturally evolved" languages such as English sufficient, with EY-style taboos and neologisms? Or are they sick to the core?
Please forgive and point me towards previous discussion or sequences about this topic.