Science is better then this. We don't need to directly observe something, it's OK to be able to just indirectly observe.
So, let's assume that consciousness is only physical. What would be the implications of that? It would imply that other physical objects can interact with it. We see plenty of evidence of that, with victims of brain damage, or when using drugs.
Now, to assume that consciousness is not physical, not only you need a mechanism for it to interact with our physical world (since it can order our bodies to do stuff) but also for the physical world to act on it.
Hence, from a scientific perspective, it seems pretty clear that consciousness is physical.
You are thinking about consciousness as it's contents. Drugs or brain damage change its contents, but don't change the presence of consciousness. Therefore that only proves that the contents are physical.
If you consider sleeping or fainting as loss of consciouness, I wouldn't be sure that's the case. Perhaps what happens then is that we lose the perception of the objects of consciousness and we are conscious of a blank state, and as we have no point of reference and nothing to know we mistakenly think that we were 'unconscious', while we were conscious of nothing.
> It would imply that other physical objects can interact with it. We see plenty of evidence of that, with victims of brain damage, or when using drugs.
And our senses. Another personal favourite example: being bludgeoned into temporary unconsciousness.
> to assume that consciousness is not physical, not only you need a mechanism for it to interact with our physical world (since it can order our bodies to do stuff) but also for the physical world to act on it
I've seen this argument before - a variation of it ties in the physical principle of conservation of energy - but I'm not sure it really holds. It assumes a pretty 'strong' dualistic model.
Even if we take the starting assumption that the mind arises from the physical world, we could say that the mind exists in a mind space, rather than a physical one. I believe David Chalmers' theory of mind takes a similar line (disclaimer: I haven't read it). [0]
If a dualistic model really does propose a suspension of the physical order, well, they've already lost.
Related: I like the way Dan Dennett answers the question of Is the mind physical?: it's physical the way a center of gravity is physical. It's not a particle, or something you can touch, but it arises from the physical world.
> Science is better then this. We don't need to directly observe something, it's OK to be able to just indirectly observe.
Indirect observations involve forming a testable (and falsifiable) hypothesis. What you're doing above is more like an attempt at proof by contradiction...
But I can assume the contrary viewpoint and deduce as well. Suppose human consciousness is non-physical. From observation (as you said) we know it can be affected by physical things -- brain damage, drugs, etc. So it must have a physical/nonphysical interface, probably in our brains.
You might say Occam's razor rules non-physicality out, since such an interface is a bit much to assume. But given that we don't have a meaningful way forward assuming physical-only, perhaps admitting one further assumption can help our inquiry - perhaps physical-only is too simple an explanation. As Einstein said, "Everything should be made as simple as possible, but not simpler."
What do you mean we have no meaningful way forward? If anything, recent advances in deep learning (and even the older neural networks) show, that we have a pretty good mathematical explanation of what consciousness could be. O-o
Imagine, if you will that the brain is an antenna, and consciousness is a soulful radio wave. If you destroy/make inert the brain, consciousness is lost, what have you shown? You may be tempted to claim that you demonstrated the fact consciousness arises from the brain, but this isn't the case here: The consciousness radio-wave still exists, but it is not being received.
The problem is a hard problem which may or may not be ill defined.
> The consciousness radio-wave still exists, but it is not being received.
So when someone dies, their consciousness continues, but is unseated from their body?
Presumably temporary unconsciousness is explained the same way?
How do you explain population increases or population decreases? Is there an infinite pool of consciousnesses, and only an infinitesimal proportion of them are being received at any given time?
Do drugs affect the receiver, or the consciousness (transmitter) itself? If it's the former, you've just conceded that some fundamental aspects of our consciousness are contingent on the receiver, and are independent of the transmitter. You can't very well answer the latter, as drugs exist firmly in the physical domain.
You'll also need to account for wildly different forms of consciousness (animals), the split-brain phenomenon, and why certain arrangements of molecules and their associated processes (i.e. living brains) can act as receivers but other closely related arrangements do not (dead brains, and living brains subject to general anesthesia). To steal a word from Dawkins, the whole thing seems unparsimonious in the extreme.
To mirror lostmsu's comment, this is a truly extraordinary claim, made in the total absence of supporting evidence. I'm not convinced it's even a coherent model.
Popper concerns itself with test-ability, not truth. Something can be both untestable and true.
Occams razor says more about human psychology and beliefs than it does about reality.
In any case I was not arguing that this scenario represents the true state of the universe, but am arguing against grand parent's argument that we can conclude consciousness is physical without making certain assumptions about the nature and design of the universe, even if empirically it is our best guess.
I am not sure I'd care about the definition of "true", that does not fulfill the Popper criteria. That is the whole point of it.
Occams Razor is a tool people use to pick the best theory (in terms of size) among theories otherwise describing the same universe. These theories are otherwise identical.
The same applies to your last point: we simply pick the best theory at hand, and that argument does exactly that.
So, let's assume that consciousness is only physical. What would be the implications of that? It would imply that other physical objects can interact with it. We see plenty of evidence of that, with victims of brain damage, or when using drugs.
Now, to assume that consciousness is not physical, not only you need a mechanism for it to interact with our physical world (since it can order our bodies to do stuff) but also for the physical world to act on it.
Hence, from a scientific perspective, it seems pretty clear that consciousness is physical.