What constitutes science? You must be able to predict events from a theory and you must be able to reproduce them. But there's a third, implied tenet that most people forget about: anyone performing the experiment must come to a consensus on the results of the experiment.

For me, "experience" is easy -- it's the most "real" thing in my reality. Vision, hearing, taste, smell? Those could all be faked some day with advanced enough neural manipulation.

Let me attempt to clarify.

Suppose you have a hypothetical person who sees an apple floating everywhere in front of him. He tells everyone that he sees this apple, but everyone else says "No, you're crazy. There is no apple there." So he takes a photograph of the apple. He prints it out and says "Look! Right here in this photograph is the apple!" Again, everyone says "I see no apple." He can consistently, predictably, see this apple. He decides to even paint exactly what he sees. And when he looks at his painting, he sees an apple, but everyone else sees empty sky.

Is this person crazy? Well, if science is determined by consensus (which it is), then yes, the majority of people would say that he is crazy. But now instead of just this one guy with an apple, let's say that everyone sees a piece of fruit in front of them. But it's a different type of fruit for each person. And they all try to tell each other that there is clearly, obviously, unmistakably a fruit floating right there in front of them, but everyone thinks everyone else is crazy because they can't see other people's fruit -- only their own.

So eventually, they decide to just forget about the fruit. Maybe it's not actually real if everyone else can't see it? (Would a person in a computer simulation see this fruit?) And so, despite everyone obviously having their own fruit hanging right in front of them, they have all decided to say that there is instead no such thing as floating fruit, since no one can come to a consensus about everyone else's fruit existing.

So there you go. That's how I view consciousness. Although I should tweak that slightly -- "consciousness" perhaps isn't the right word. Consciousness can be manipulated with drugs and sedatives. What I am really referring to is the act of "experiencing" something.

First: 'Science' does not embody the whole of human knowledge, not at all. That's not even what it's for. It is a true thing that 1+1=2 (with standard definitions, Peano arithmetic, etc), but science has nothing to say on this matter.

Second: The fact that other people talk about this fruit they see, and you yourself have this fruit that you see, is very strong evidence that people have fruits, even if, with our current understanding, we can't verify it from physics.

Third: I do believe consciousness exists. I think (in fact it seems self-apparent to me) that consciousness is a property of processes or algorithms. Can I explain how exactly it arises? No, but then for virtually all of human history we had no idea how, say, biology or magnets or fire could come out of physics either.

Fourth: Just because a process has some property doesn't mean we'll ever understand it in a satisfying way - even very simple processes (care to explain how the current best-candidate for BusyBeaver(6) works?) This is not the same as that property not existing.

Finally: This was in my original post as well, was in fact the entire point of said post, and I can't seem to find a response in your post. If you accept (as is a part of the p-zombie postulation) that the reasons you say things like 'I am conscious' are entirely because of physics, do you think that this means your consciousness has nothing to do with your claim to be conscious? That seems absurd to me, and to me it seems that the conclusion must be, given the above, that consciousness does in fact fall out of physics.

For clarity, here's that final argument spelled out again.

1. My claim to be conscious does have to do with the fact of my consciousness. (Agree?)

2. My claim to be conscious is completely determined by physics, since I would also make it in p-zombie world (that is, the world which is by hypothesis completely determined by physics). (Agree?)

3. Therefore, the fact of my consciousness must fall out of physics. (Agree?)

Or in set-theoretic terms, because that's how I think:

fact-of-consciousness \subset reasons-for-claim-to-be-conscious \subset physics implies fact-of-consciousness \subset physics.

Do you disagree?

First: Yes, I agree.

Second: Hmm... I don't know. People talk about ghosts a lot as well. There are many people who claim that they see ghosts. But I don't think that is strong evidence that ghosts exist.

Third: We need a consistent definition of consciousness here. It would waste a lot of time if it turned out we were debating different concepts. I believe your idea of consciousness is that it is an emergent phenomenon that arises from simpler processes, much like how biology arises from the simple laws of QM. Is this correct? If so, then with that definition of consciousness, I agree with you. And we will learn more about it as time goes on.

Fourth: Yes, I agree. Chaitin's constant is my favorite exemplification of that idea.

Finally: "Do you think that this means your consciousness has nothing to do with your claim to be conscious?" Yes, that is exactly what I think. Although replace "consciousness" with "the act of experiencing existence" and that is a much closer semantic match to what I am attempting to convey.

> 1. My claim to be conscious does have to do with the fact of my consciousness. (Agree?)

No, for the simple reason that you can write a computer program that prints out "I am conscious." Its claim of consciousness is only due to a program that someone wrote.

> 2. My claim to be conscious is completely determined by physics, since I would also make it in p-zombie world. (Agree?)

Yes, I agree with that.

> 3. Therefore, the fact of my consciousness must fall out of physics.

Were 1 and 2 true statements, they would indeed imply 3. But since I don't agree with 1, 3 also doesn't seem to be true.

I wouldn't call that a definition. Here's a working one: my consciousness is the part of me which thinks and feels, which enjoys music and mountains and friends and so forth. Computers as of now can take input, but can't experience input the way I do; the gap is what I call consciousness. (To this definition your above description does apply.)

> "Do you think that this means your consciousness has nothing to do with your claim to be conscious?" Yes, that is exactly what I think. Although replace "consciousness" with "the act of experiencing existence" and that is a much closer semantic match to what I am attempting to convey.

This is the bit I'm having trouble with. For me, I experience things, and then state that I experience things. The relationship is direct and causal. From what I understand you experience things and then state that you experience things, and these facts are completely unrelated? I'm pretty sure Occam had something to say about that.

"Causation from particle-wave interactions". What do you mean by this? If you're referring to determinism, that's already been ruled out by HUP (unless you support superdeterminism, although few scientists do; t'Hooft is a notable exception).

Valid data type? When did the discussion switch to type systems? I'm sorry, you'll need to clarify what you are trying to convey.

I'm sorry your highness. I didn't realize I'm speaking to an authority here.

>Causation from particle-wave interactions". What do you mean by this?

I mean saying firing of neural circuitry X correlates to experience of Y. Given the right tools you might be able to do that and create a valid mapping of causation.

>Valid data type? When did the discussion switch to type systems?

What you can't do is capture experience in formal language. We'd like to symbolically capture the experience of "seeing blue" for example but no data type maps onto qualities beyond nominal signifiers of our own personal experience.