I've never considered humanity's distinctive feature critical thinking, because we do still run primarily on instinct and obey social constraints not exclusive to our species. I'd say the depth of communication is more unique, and what really separates humanity from (known) species. And because this sentence fits nowhere else in my post, not here either really, I know,and I don't feel like constructing some ham-fisted segue (like this): The computer emulates the human mind so superficially and with such a precise scope that any claims of intellectual infringement are baseless.
I've also never understood a fear of technology, computers specifically, because while it makes great science fiction, your thinkpad won't develop sentience on its own, or for that matter with even the most profound stimulation. The limits of such a system are clearly defined-there can be no 'machine revolution' because a machine does not have self-interest at heart. I suppose a machine could subjugate humans if it fulfilled its own programming, such as the loophole in Isaac Asimovv's 3 laws of robotics (a robot can not harm a human, a robot must obey a human unless obeying a human would violate the first law, a robot must protect itself so long as this is concurrent with the first two laws-the loophole is that robots believing humanity will destroy itself left unchecked can commit violence against humans as a preventative measure)...but honestly, even that is too far out there to warrant serious discussion because programming is so specific. Automated factories can also never displace humans from work on any relevant scale-it's simple economics, if you have machines to make consumer goods without a consumer base, you're running a doomed enterprise. Ignoring that, what about repairmen for machines? Or repairmen for the machines that repair broken machines? Etc.
And in response to PPA:
How are you defining nature? If you mean living organisms, it would require concerted effort to eradicate all life on a planet. If you mean the planet itself, I admit that
we are on our way. If you mean the universe, the concept of something completely untouched by humanity, that's going on independently.
Which brings me to another disjointed point: the conventional use of the word 'nature' makes no sense. It's defined by too many as being an area untouched by humans...another form of life. Does our sentience make us different, coopt natural processes? If it does, where do you draw the line-is a reef patrolled by dolphins, or a section of jungle where gorillas live, no longer 'natural'? They're smarter than other species, comparable to humans in that respect-so really, nature is being assessed as a matter of relative intelligence, and therefore the only nature that can exist is an area without any life at all.
To repeat: this will destroy itself before we have the chance, so stop condemning society for its supposed disrespect towards 'nature'...or at least get your terms straight.