When some physicalists talk about consciousness being an illusion, they're generally talking about the experience of being the centre of reality, they don't mean we don't have these experiences. They're addressing the fact that the brain isn't always conscious, that consciousness seems to go away completely in some situations, so for them it's not a permanent aspect of ourselves. That's all.

I prefer not to use the 'illusion' terminology because I think it's misleading. We do have a real experience of consciousness, just not always. For me Buddhism and panpsychism, and the idea of consciousness as being fundamental is a hierarchy inversion error.

If consciousness is a computation or an emergent phenomenon of brain activity processing information, then we are a kind of information system. It doesn't therefore follow that all information systems are in some way conscious. That's like saying horses are all animals, therefore in some way animals are all horses. Yes we have some things in common with all information processing systems, so we have some of the same features like persistent memory and such because we're members of the same conceptual category, but that doesn't make us the same thing.

I think consciousness is the more fundamental thing, because it’s the only thing I ever have experience of, and that everything else arises from that (including the physical world). To me that’s the simplest explanation

Taking a step further, I think neither consciousness nor physical reality really exists, it’s all emptiness (see Heart sutra)

I don’t see how that’s a simple explanation. We know we lose consciousness, totally, on a regular basis yet when we awake the world is still there. It’s always consistent and doesn’t radically change as our consciousness changes. We can set devices to record activity in the world while we are unconscious, and their recordings seem consistent. The simplest explanation seems to be that the world is real and persistent, but our consciousness is transient.

If the world arises from consciousness, we would expect that changes in conscious states would persistently alter consensus reality. But we never see that happen.

Again see the Heart sutra

> Occam's razor = the theory with the fewest parameters should be preferred, or often interpreted as the simplest theory.

> Do you think that humans universally or even have historically interpreted physicalism as a simpler theory than a non-materialist one? I don't think so

Backtracking a bit from that little word "theory", it's foremost about being able to formulate predictions about the real world. So, designing a suspension bridge over there, how much steel do use per cable? 1 ton? 2 tons? 42? Use the eight consciousnesses, sure, but get the answer, build the bridge, and be the first one to cross it.

If you don't have two competing theories that offer a prediction, there is nothing to apply the Occam's razor to.

A theory which is a mix of physics (for steel bridges, etc.) and Buddhism (for this or that domain) does work for many predictions. It is also inherently much more complex than "only use physics".

I think you are getting confused between the word theory and the word model, which are often interchanged in physics unfortunately.

A "model" is predictive, but a "theory" explains. A theory of consciousness has no need to predict the future. A model of consciousness would. This word has just been mixed up a lot in science. The reason is that theories in physics are almost always also predictive models. However, this is not usually explicitly the case in philosophy.

> A theory of consciousness has no need to predict the future.

If you don't feel the need to predict anything about consciousness in the real world, I'd say I won't be interested in such a "theory" (or "explanation"). But glad to see your take on the definition of the term.

Going back to Occam's razor, if you only apply it to get the simplest map (in some sense of "the simplest"), and abandon verifying whether it predicts the territory or not, it seems a blank map always wins.

>Do you think that humans universally or even have historically interpreted physicalism as a simpler theory than a non-materialist one?

To be fair with humans, the simpler theory is almost always "my neighbour is a witch, she did it"

Hand waving complexity as that thing you feel in your gut instead of having some proper definition for it was and still is the standard human experience

> To be fair with humans, the simpler theory is almost always "my neighbour is a witch, she did it"

Then why appeal to Occam’s razor?