It IS our fault that we're misunderstood before the explanation, but when people insist, AFTER the explanation that we mean Mary is equal to Jesus when we obviously don't mean anything of the kind, that's not reasonable”
I agree that it isn't reasonable to attribute meanings contrary to those already stated so let's see how this would work:
MD says I'm a vulgar pagan but he means I'm a common uneducated or unenlightened person. So I'll explain to MD that when I say he's an insane cur he shouldn't take the common meaning of my words but rather what I've said they mean and so should others, it's jargon.
It's not reasonable because it requires us to say a person doesn't mean what he has said he means. But neither is it reasonable for anyone to expect readers or hearers to be familiar with everyone’s meaning or solicit it when they use common English words with widely accepted meanings.
With or without explanations your use of an English word doesn’t change the meaning of that word. Nor does attempting to use an archaic sense.
If you say I'm a vulgar pagan I have every reason to take what it means in the language I speak no matter how many appeals to jargon are made. I...I don't speak your jargon and I feel it unreasonable to ask me to start using it by accepting its vocabulary.
Every group has a jargon to some degree but jargon is suitable for use only within that group. Patent means one thing within the medical profession and commonly another without for example.
Ahhh...co-pilot is still a pilot and must be able to perform all the flight operations of the pilot. And he may in fact assist in flying the plane when necessary. Otherwise he's just a passenger in the right seat.
I think that your emphasis on current common usage is treating a moving target as if it were fixed.
Groups have their dialects. If I wanted to talk to a Southerner I learned what he meant by "jitney", "carry", "poke", "buggy" and the rest. And after a while I found myself using the words as they did.
If I want to talk to a sailor, while he should know that what he calls a "line" is generally called a "rope", and "port" is not just an opening or a fortified wine but it is also a direction.
And here's an instance: TO me "mad dog" means a rabid dog. I took the name because I was exposed to rabies. But if you mean a psychotic dog, I can work with that. Just letme get a note from my pshrink.
I think there needs to be give and take. Part of that will be openness on the part of all parties to the idea that the other party was using "shop talk" wiuthoutmeaning to or knowing that he was doing so. I have NEVER (that I can recall) taken 'co-' tomean 'equal'. Even among co-authors usually one takes the lead. Put that on your ISP and save it.
And a co-pilot is still subordinate, is s/he not? He is not equal in rank or responsibility to the pilot, unless something happens to the pilot. If it comes to orders, the pilot gives them and the co-pilot takes them, is that right? I think it is.