I think that you are unintentionally conflating two very different questions:
1). What is the mechanism that causes us to perceive certain entities, including humans, as possessing consciousness ?
2). Let's assume that there's a hidden factor, called "consciousness", that is sufficient but not necessary to cause us to perceive humans as being conscious. How can we test for the presence or absence of this factor ?
Answering (2) may help you answer (1), but (2) is unanswerable if the assumption you are making in it is wrong.
I personally see no reason to postulate the presence of some hidden, undetectable factor that causes humans to be conscious. I would love to know how is it exactly that human brains produce the phenomenon we perceive as "consciousness", but I'm not convinced that such a feature could only have a single possible implementation.
This is indeed important with respect to morality:
I may consider it important to know (if only I could know), whether they really are happy or suffering, or whether they are just automata pantomiming the behaviors of happiness and suffering.
If the presence of consciousness is unfalsifiable, then you can't know, and you're obligated to treat all entities that appear to be happy or suffering equally (for the purposes of making your moral decisions, that is). On the other hand, if the presence of consciousness is falsifiable, then tell me how I can falsify it. If you hand-wave the answer by saying, "oh, it's a hard problem", then you don't have a useful model, you've got something akin to Vitalism. It'd be like saying,
"Some suns are powered by fusion, and others are powered by undetectable sun-goblins that make it look like the sun is powered by fusion. Our own sun is powered by goblins. You can't ever detect them, but trust me, they're there".
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A list of some posts that are pretty awesome
I recommend the major sequences to everybody, but I realize how daunting they look at first. So for purposes of immediate gratification, the following posts are particularly interesting/illuminating/provocative and don't require any previous reading:
More suggestions are welcome! Or just check out the top-rated posts from the history of Less Wrong. Most posts at +50 or more are well worth your time.
Welcome to Less Wrong, and we look forward to hearing from you throughout the site!
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