Do we even have a consensus on which animals are conscious?
Thus, even if we cannot clearly state for any given animal whether it is or is not conscious, we can still clearly state that, say, a coffee maker is not conscious, even if it has rudimentary processing capability, or that a person is.
As I implied in another comment[0], I believe it would be both possible and valuable to construct a set of conditions that we collectively feel are necessary, if not sufficient, to define consciousness. That way, we could at least rule it out as long as no AI meets those minimum standards.
a coffee maker might include a temperature sensor (thermistor) and a heating element. does it predict the future? yes: it has an expectation of the future temperature given the current state. does it model itself as an agent? to a limited degree: it considers the future effects to the thermistor which its immediate control of the heater has, it might even run hypotheticals over a set of different heater controls. throw in a pressure sensor or a flow meter and some valves for more fun.
now, i haven’t read much literature post 90’s on this, but one of the more prominent components of consciousness seemed to be: modeling yourself as an actor within a larger setting, and using that to produce outputs based on predictions and thereby cause a specific future(*). does the coffee maker qualify?
also i don’t think many people think of consciousness in a binary sense. that grey area you describe may be less of “we don’t know if these are conscious (binary)”, but rather “we don’t know if these things have experiences which are relatable enough to our own to be worth considering in the motivating questions (i.e. ethics).” and the things at the bottom (the coffee maker) are more like “whatever experience this thing has is so far removed from our own that we’ll never be able to understand it in human terms (like pain and suffering or wants and desires).”
(*) though some people like Dennet argue that the conscious experience might not always be involved in the causal part of this loop.
If conscious is defined as “to have subjective experiences”, then I don’t believe “other people are conscious” is coherent.
The argument I hear usually is that other bodies are constructed like my body and I’m conscious therefore they are probably conscious too.
But I think this completely misses the point. The issue is the proposition itself. How can that proposition be translated into empirical claims? If the answer is just that other bodies are like my body, then conscious is just a fancy synonym of “is a human being”.
Coherent but about as likely as Last Thusdayism. You have to factor the probability and potential mechanisms of what might give rise to consciousness and if you do you should have a very low probability on other humans not having it, just as you have a low probability on a random human you meet physically not having a brain without having to confirm by looking inside their head.
But in principle, I could open someone’s skull and look for a brain. How would I examine another human body for consciousness?
I’m trying to question the coherence of the proposition itself, and not trying to refute an argument in favor of it.
> You yourself can also never physically check say Plato's skull either but I doubt that deters you from thinking he had a brain.
The Plato’s brain question (PB) confuses me, but here is my attempt at an analysis.
First, I think PB is tricky in the same way that all historical propositions are tricky. And I think this trickiness is different than the trickiness around the proposition “other people are conscious”.
Second, here is a scenario that I think is like PB. Consider the proposition, “The Great Wall of China exists.” I’ve never been to China, but say you go and tell me that you saw the wall. And in principle I could go see the wall for myself. But now what if the wall is destroyed before I go to see it? Was the proposition that, “The Great Wall of China exists”, coherent before the wall’s demise, but now incoherent?
But if you tell me, “I am having subjective experiences”, how can/could I ever in principle examine this for myself, as I could the Great Wall?
The point is that just because you can't prove something to yourself it doesn't make the belief incoherent. And you can use your other tools to arrive at likelihoods for said belief.
At any rate, there's plenty of things we believe about say quantum mechanics without being able to observe them directly by using theory and observing secondary effects.
In theory it's also possible to eventually have an exact definition of what we mean by consciousness, figure out which parts of the brain are relevant in what ways and observe secondary effects and use theory to confirm others have it same as with QM. It's all caused by physical effects and at a higher level than things we already reason about just fine.
If a proposition doesn’t make predictions about my empirical experience then what is it saying?
And if a proposition does make such empirical predictions, than it’s effectively just a name for those predictions.
That’s essentially the view I’m coming from.
> At any rate, there's plenty of things we believe about say quantum mechanics without being able to observe them directly by using theory and observing secondary effects.
I don’t know any physics so I can’t comment.
Why are propositions about consciousness different from propositions about faeries?
Ultimately they are not. It's just that the evidence points towards an extremely low chance of fairies being real and extremely high chance of others being conscious in a comparable manner to how you are conscious.
Every North American faerie weighs more than 10kg.
Every North American faerie weighs 10kg or less.
As another example, I suggest that “Every idea weighs more than 10kg” and “Every idea weighs 10kg or less” are both not meaningful, because it is not possible to measure the weight of a given idea.
And so consider a claim like, “Consciousness has property X”, how can I decide whether or not such a claim is true?
edit: That last claim should have been, “Some other person’s consciousness has property X”.