Now as for the implication that anesthetics sedating plants has ANYTHING to do with this/whether or not they are conscious: no. No sorry, not buying it. Need more science.
This just suggests we may have similar inhibitory biochemical responses to certain organic compounds.
That's not surprising since were all made out of hydrocarbons & many anesthetics have relatively simple structures.
The definition must apply to humans. It must not apply to rocks. It should probably not apply to plants, fungi, bacteria, and worms. It will probably apply to dolphins, dogs, and pigs. Will it apply to companies, robots, cities, ant swarms, chicken, or fish?
I'm reminded of the xkcd comic about making a computer out of tons of rocks in the desert[1]. Sure, one rock is crystalline (enough) and has essentially no stimulus-processing power. But a pile of rocks, arranged just so, can be set up so as to respond to certain stimuli that, to an outside observer, seems like thought/consciousness. This is the Chinese room problem[2] recast.
By approaching it in this way, we are forced to reconsider: what's so special about humans that makes how you define consciousness more applicable to them than a rock or plant? Why exclude rocks at all?
I'm firmly in the camp that any attempt to quantify consciousness will necessarily be a matter of degree, with no system exhibiting zero consciousness except a perfect crystal (i.e., zero entropy).
Alternatively are you implying that human consciousness is meta physical in nature?
How about - ability to adapt to environment and select good actions depending on situation, learning from reward/loss signals.
The dictionary I have close at hand claims:
consciousness |ˈkɒnʃəsnɪs|
noun
1 [ mass noun ] the state of being aware of and responsive to one's surroundings: she failed to regain consciousness and died two days later.
2 a person's awareness or perception of something: her acute consciousness of Luke's presence.
If a bacteria senses a change, say in salinity, and moves away, can we say the bacteria is / was aware of the change.
What does awareness mean. It sounds at least as slippery as conscious.
That seems closer to the everyday definition of consciousness most people operate by, than to the hopelessly bikeshed attempts at making it a uniquely human thing.
Consciousness, like Artificial Intelligence, is a slippery concept. They both tend toward being unattainable by anything-other-than-human:
i. As we implement progressively more abstract concepts in computers, those layers of abstraction become mundane things that computers can do.
ii. As we learn more and more about how non-robot-like other organisms are we can quite easily push consciousness further in to the human-only corner by just adjusting the definition of consciousness.
Insofar as consciousness can be defined as the state of being aware of and responsive to one's surroundings the yes, plants certainly are conscious.*
Do they posses self-awareness?
My favourite definition for consciousness is the following:
If it is something to be like a particular thing, then that thing is conscious.
If it is something to be like a bat, then a bat is conscious. If it isn’t something to be like a bat - the “lights are off” so to speak - then it’s not conscious.
Edit: clarity
At least as you've stated it, that's a circular definition.
I guess I'm focusing more on the "lights are off" part, although that's just an aside. "Conscious" and "lights are on" seem like alternate ways of saying exactly the same thing.
Nagel's "is it like something to be" terminology has always struck me as wilfully contorted and confusing, but amounting to the same thing again -- you're conscious if you're conscious. It doesn't help us explain consciousness and it doesn't even help figure out what things are conscious and which aren't. Is a plant conscious, or a rock? Writers can certainly imagine what it might be like to be those things.
After you are yourself again you'll need to interpret the acquired memories. You remember echolocview of the room (bats have memory, it's testable), hunger, disorientation and some other sensations. Does it mean that bat is conscious? What will you remember differently if bat wasn't conscious? You'll remember nothing? But memories are there and you should have access to them. The lack of self-awareness? But you don't know how you would remember the presence of self-awareness in a bat.
Nothing is really static in life. So nothing ever really is always just a thing, it was one thing, now it's a slightly different thing.
It is like something to be a human. But the conscious experience of a bat (if it exists) may be completely alien to us in every way. That’s not relevant to what it is to be like a bat. The only important thing is if it is like something to be a bat.
It is based on our illusion of understanding what it is like to be a human, but upon closer inspection it bears no real content.