I am not sure i've encountered the claim in the hard sense you imply. Maybe you could provide an example. If they do, then I would agree with you - no one can claim to 'know' (with respect to 100% proof) and it is logically questionable. However, this does not make it true or false - thats all i was adding.
I remember a poll on this board some time ago where people were asked how sure they were there was no life after death, and a high percentage were near certain, and the majority were very confident.
We could start a poll again, but I'm sure the results wouldn't have changed much. The consensus amongst skeptics is that there almost certainly isn't one. I'm wondering where this "almost certainly" is coming from, since it seems to be grounded in a confident belief that WYSIWYG as far as reality is concerned.
Again, to reiterate, I don't believe in one either.
I am still confused what you mean - but dont worry - its probably me. Anyone else get a handle on this metaphor?
Have you seen the Matrix films? It's just an example of what I'm talking about.
Otherwise, take dreaming and hallucinating as examples. Some dreams, hallucinations, and especially NDEs can seem incredibly real a lot of the time, especially while we are experiencing them, and they can seem perfectly normal, make sense, and we often don't even question the possibility that it might just be an illusion.
Where does our confidence come from that reality itself is not a dream, or a computer simulation?
How is brain science compatible with a notion of duality? Do you have any examples for us all to consider?
Not duality, that would imply a soul communicating with the brain, right? I'm talking about a different type of monism, involving consciousness, or in the case of a computer simulation, I've no idea what you would call that, but it isn't dualism.
As for examples, let's take the most simple example we have - whacking someone over the head. The fact people lose consciousness when this happens could imply that reality is created by the material brain, however, I think this notion is completely compatible with every other underlying reality example I have mentioned.
If reality is a computer simulation, we would expect this functionality to have been programmed in. I've had many dreams where shaking my head would cause me to lose dream consciousness, falling down would cause me to wake up completely, and hitting my head in the dream would certainly cause me to regain consciousness. If consciousness creates the material world, we would also expect it to have created the brain, and to utilize it. Therefore, we would expect playing with the brain to have the same affect as in a material reality.
None of these experiments seems to be more suited to materialism than its opposite, or illusionary reality hypotheses.
Is there some circularity here? - you say it 'should' make us prefer brain-based models (I totally agree). I have my reasons - what are yours? You will proabably find when you identify your reasons you will answer the second part of your question to some degree.
My reasons are mostly practical reasons, not evidence based. In order for us to conduct science successfully, we have to have faith to some extent that the Universe is predictable, consistent, explainable, sensical, and that attaining a theory of everything eventually is a likelihood.
However, if we accept any model other than materialism as an axiom, all that is thrown into doubt. We could have the urge to give up on a problem because it is fundamentally unsolvable, nonsensical, or just a weird computer glitch of some kind, or even something deliberately programmed in to baffle us forever.
Most people will now say that the fact science has been successful is proof that there is a consistent material reality, but by the same token, we can cite any current failures or lack of knowledge of science as evidence of the opposite - like QM.
Although this is an argument from ignorance, it does not mean it's likely that QM will ever be understood, or ever could be, because solving it seems the biggest challenege to science to date.
Could it be so difficult to understand because our underlying reality model is incorrect? It's certainly a possibility.