Well, the biggest change in language was that words became defined rather than "named".
So in the Good Old Days, every noun was a sort of Linnaean taxon ─ you couldn't say 'rose', you said 'Rosa glauca', or 'Rosa palustris', right? You couldn't say 'rock', you said 'solid granite' or 'solid basalt' or whatever. You couldn't say mother, you had to say 'homo sapiens mother' and so on. Is that the idea?
I don't know why you'd praise such a clumsy arrangement, free of metaphor, nuance, humor, poetry.
Everybody now must deconstruct sentences on a real time basis and no two individuals take the exact same meaning.
How could that have been different in the Good Old Days? Each listener would bring his or her own understanding to the words (even if they were 'Rosa palustris) because we're always our own interpreter ─ interpretation is a task that can be shared, but not delegated.
Besides, if what I want to say is capable of precise meaning, I dare say I can say it precisely. Usually near enough is close enough ─ 'Is this the train?' ─ but I can say 'Is this today's 11:23 express to Smallville?' if need be. As long as I understand what facts I want to communicate, I can precisely communicate them, so I don't see a problem.
They invited the listener into their brain to see their "thoughts".
Who are 'they', exactly?
And how do you know they 'invited the listener into their brain to see their thoughts'?
If you were keeping pace with brain research, you'd know that would be a pointless exercise. Thoughts don't exist in words until we express them. If you could read my brain you still wouldn't know what the next word in this sentence would be till I'd typed it, not least because my conscious brain wouldn't know either.
it's impossible to say anything that can't be deconstructed because that's how modern language works.
You can deconstruct anything, even 'This plant is an example of Rosa palustris'. Whether you'd be better off doesn't matter ─ you could do it. Or I could, anyway.
Ancient Language was logical and it couldn't be deconstructed or it lost its meaning.
Since, as I said, any coherent statement can be deconstructed, you haven't said anything that suggests to me that your statement is true. Derrida and friends invented a game, the great majority of uses of which were trivial.
The brain is the generator of awareness and sense of self, but it's not a 'life force'. There's no single life force: human life is the result of a complex set of biological functions working cooperatively. Loss of effectiveness of even one essential function can result in death.
the same natural logic that governs reality (what we naively call the "laws of nature").
The consistencies of behavior of objects in reality and their relationships are something we observe and seek to understand; but our equations are models, not reality. The map is not the territory. and all conclusions of science are tentative.
It can be quite difficult to tell if any individual sentence is Ancient Language or not.
Didn't you just say that if you can't deconstruct it, it's Ancient Language? What's an example of an undeconstructible but coherent factual statement (now that I've said there aren't any)?