[andyh2]

I believe the broadest consensus defines consciousness as having a subjective experience.

What's unclear, and some deem impossible, is how we can externally detect consciousness. A machine could act and respond in a manner indistinguishable from humans but still be unconscious.

[tim333]

>A machine could act and respond in a manner indistinguishable from humans but still be unconscious.

There are some types of behaviour that could make it clear a machine was conscious from a practical point of view. Say you had a robot teacher and threw something when it's back was turned and you tried to frame a fellow classmate but the robot saw through it and told you not to do that. It would be fairly clear it was conscious of what was going on from a practical point of view. You could of course say it's not real consciousness because it a robot but how do you know a human teacher is conscious beyond such behaviour?

A statement like "They've figured out what we're up to and are thinking how to stop us, though luckily they are not conscious." doesn't really make sense regardless of what the they is.

[dragonwriter]

> I believe the broadest consensus defines consciousness as having a subjective experience.

A useless definition from an empirical perspective.

> What's unclear, and some deem impossible, is how we can externally detect consciousness.

Defined that way, its impossible to objectively verify by definition.

[freshhawk]

So then define "subjective experience" without "it's that thing we have" (which thing?) or using the word subjective. This feels to me like replacing one undefined term with another.

Also Dennett has an excellent rebuttal to the concept of p-zombies (unconscious entities indistinguishable from conscious ones) imo.

[DonaldFisk]

And David Chalmers has an excellent rebuttal to Dennett's rebuttal. Different people take different sides, and I'm with Chalmers on this one.

The evidence for the conceivability of p-zombies is in your living room, if you have a television. You can see people on it and they behave intelligently. Are they conscious? Of course not, they're just red, green, and blue dots. Maybe we could make this a bit more realistic?

You're now in a very realistic virtual reality. Your character is conscious, because you are. So is the character being played by your friend over there (assuming he's not a p-zombie). But what about the characters next to you? Maybe Doug Lenat and Geoffrey Hinton collaborated and developed an AI as intelligent as a person, and that's what controls them. They can't be conscious, because they're just pixels like the dots on your flat-screen TV, so not conscious in the virtual reality, and they're not conscious in the real world either, because they're just software, which is an epiphenomenon, like wetness or tidiness. The computer which runs the VR, and the AIs, might be conscious but that would be a very different consciousness from yours. Maybe it senses voltage levels at its memory addresses, but it certainly wouldn't see you or the submachine gun you're carrying in the VR.

Maybe we already are in a virtual reality. Nick Bostrom thinks we might be. If it's sufficiently realistic, there might be no way to tell, and no way to tell whether everyone is conscious, or nobody is conscious except you.

[andrewla]

Ugh... replacing one vague and undefined word with three vague and undefined words (I'm including "having" because that's a hard one to nail down in context).

    function i_am_conscious(x) { return x + Math.random(); }

This function has a subjective experience.

To avoid any discussion of consciousness becoming a discussion of the meaning of the word "consciousness" we have to accept that consciousness (like everything else in the real world) is not a boolean property, but rather a subjective "I know it when I see it" sort of thing. Or in Bayesian terms, it's a weighted evaluation of evidence against a vast array of mostly unknown priors.

That's why I think it will sneak up on us; there will be systems that some very small group of people (mostly crazy) think are conscious, then systems that a slightly larger group of people (maybe more crazy, maybe less) think are conscious, until one day You wake up and realize that You are one of the crazy people.

But directed attempts to satisfy some definition of "consciousness" in a system will just result in a counterexample to that definition.

[joe_the_user]

I believe the broadest consensus defines consciousness as having a subjective experience.

I could go one further and say "I believe the absolute broadest consensus defines consciousness as having a conscious experience." and only say slightly less vague than your statement.

Conscious, subjectivity, awareness in some of their meanings are just synonyms for some internal experience or other. There's a sense that this internal experience reflects things in a unique way, that it's not controlled by outside constrains, that it reflects a person's unique choices not controlled by any fixed pattern or program. But it's just primarily an intuition.

[drabiega]

Not just a machine. I agree with definition of consciousness, but it's implication is that we can only ever be sure of our own present consciousness. The consciousness of other people and even our past selves can't be verified.