> I was speaking casually and using "fair" as slang for "helpful, reasonable, and widely-assumed".

I like the convenience of this wildcard, because it also applies to everything you say in this comment. It's a neat trick: anything I call you on "doesn't count", because you didn't intend it to be technically true, because that's "not realistic" and "not reasonable".

> And yes, "widely-assumed" is also cultural - but in this context, that _is_ relevant....

Let me guess: that which you perceive to be relevant "is" relevant, and that which is not, is not.

Am I close? Is this contrary to how your thinking works? Do you not have at least a tendency to agree with your own opinions?

> ...because I assume that those I'm speaking with are making common and reasonable assumptions within our shared culture...

Let me guess: the symbols you are using here ("reasonable") have no strict definitions?

> ...just like I assume that the words that I use mean (roughly) the same thing to me as they do to you.

Give up the cognitively magical "roughly" and where are you then?

> Otherwise, communication and collaboration are impossible....

Incorrect. Not only is there is no requirement for communication to be even remotely accurate, our culture is highly aligned against such communication. Take your comment for example: you are literally defending speaking deceptively, and describing accuracy in a pejorative manner!

> ...unless we construct language from first principles in every discussion.

Its an interesting idea!

>> without it, any discussion will founder > Good!

I'm gonna reinstate the full context, lest others be misled by your reductive (thus deceptive) framing:

>> ...since, without it, any discussion will founder

> Good! Our never ending mass self-deception during our oh so enjoyable (mandatorily so) conversations is the problem.

Carrying on...

> If you think is is preferable to have discussions that go nowhere and yield no helpful outcome in order to remain _technically_ (not-in)correct, vs. taking a small number of reasonable assumptions as axioms ("our perceptions are _probably_ not hallucinations most of the time") which allow us to reach helpful conclusions that increase human happiness, then you and I will never be able to reach agreement on basically anything.

I like this because you are framing the situation as being that attention to accuracy/truthfulness will necessarily yield failure. Considering the site we're on, I'm gonna go out on a limb and assume that your feelings on the matter change when it comes to things like science, engineering, programming, etc. I bet that in these domains, you not only believe the opposite of what you're saying here, I bet you praise these disciplines for the very thing you are criticizing here. (I wonder how far back in your history I'd have to go to find evidence).

There is a whole load of other things here that could be critiqued with ease, but I've gt a busy day ahead of me so will have to pass.

>> Is "human history is vanishingly-short on a universal scale" the(!) point of contention here (in the opinion of all participants)

> I don't know - if I try to put myself in your position, it seems to be that I cannot assume or know anything....

Your problem is this: you are not trying to put yourself in my position, you are trying to put yourself in the position of your subconscious mental model of me. It's a very common error, due to it being fundamental to the culture we've been raised in.

> and thus that I cannot make any claims about the opinions of any participants (or even that they exist), and thus banana wombat elaborate polyhedron.

Ah, here you seem to be leveraging humour, a very popular technique in both rhetoric and culture/perception. I am duly impressed, though not so persuaded.