Well epistemology is hard, which is why I said "believe".
However, the evidence for materialism is that many different consciousnesses exist, and seemingly come into being and cease during the temporal process of the physical world. That would seem to suggest that the consciousnesses are functions of the physical world, rather than vice versa. (Unless you're a solipsist?)
Perhaps I'm a solipsist, I generally agree with most of what's on the wiki description. I define consciousness as my feelings, perceptions, thoughts. We imagine other people have consciousness because they act like us. We could define consciousness in a non-solipsistic, objective way, but it would be a fundamentally different thing. Maybe one reason why the hard problem of consciousness is hard is because people hate that solipsism is part of the answer.
By the way, one important argument I forgot to mention that leads to a possible way to define the "third-party" / objective consciousness (in the last point):
- Consciousness is not physical.
- Physical brain can obviously affect the state of consciousness.
- Can consciousness affect the physical brain though? I believe yes, because otherwise we would not be talking about this, I would not write here about consciousness not being physical. However, I'm less convinced about this than the above.
- The consequence is that we should be able to observe something fishy going on in the brain, for example supposedly random quantum processes not being random, which would "break" current physical laws.
- Brains with this fishy behavior are conscious. A fun theory - most likely wrong though - is that you can "tune" / connect physical systems to a consciosness by arranging them in specific way or whatever. And during evolution, the brain has learned to do that, because it was evolutionary advantageous.
More generally, I believe your position is a form of Monism (the universe is made of one thing) called Idealism (that one thing is the mind). Other forms of Monism are Materialism (everything is matter) and Neutral Monism (both mind and matter are made of something else).
>We imagine other people have consciousness because they act like us. We could define consciousness in a non-solipsistic, objective way, but it would be a fundamentally different thing.
I think most people would say conciousness just refers to the experience of qualia, which doesn't require redefinition to allow other people to have it.
>Can consciousness affect the physical brain though? I believe yes, because otherwise we would not be talking about this
I don't think it's necessary. We could essentially be p-zombies, but with a mind along for the ride. We experience making decisions but that's just a projection of the physical brain's processes.
However, the evidence for materialism is that many different consciousnesses exist, and seemingly come into being and cease during the temporal process of the physical world. That would seem to suggest that the consciousnesses are functions of the physical world, rather than vice versa. (Unless you're a solipsist?)