Knowing this, you compare your own experience with reports by others, and find that, despite some startling variety in social and cultural practice, humans all more or less go through life experiencing the world in a way that more or less maps to your own experiences. You find that even Helen Keller, despite her tragic disability, wrote about experiences which you can simulate for yourself. You conclude that if you somehow swapped places with her, she would be able to map the sensory input of your physical sensors to her own experience of the world, and vice versa.

This leads you to think that our physical brains are performing a process that models the world, and it does so consistently. After reading up on people's experiences, you also learn that our subjective experiences are constructed, moment by moment, by a combination of these world models, real-time stimulation, abstract feedback loops of conscious and unconscious thinking.

The more you read, the more evidence you have of this strange loop being the default case for every instance of a human having a brain and being alive.

The Bayesian probability that you are conscious, because of your brain, given all available evidence, approaches 100% certainty. You conclude your brain is more or less the same as anyone else's brain, broadly speaking, and this is supported by the evidence provided by a vast majority of accounts from other similarly brained individuals through all of human history.

Since your brain doesn't have a particular difference upon which to pin your experience of consciousness, and the evidence doesn't speak to any need for explanation, Occam's razor leads you to the conclusion that the simplest explanation is also the best. The living human brain is necessary and sufficient for consciousness, and consciousness is the default case for any living human brain.

The posterior probability that any given human (with a "normal" living brain) is conscious approaches 100% certainty, unless you can specifically provide evidence to the contrary. Saying "but what if p-zombies exist" makes for a diverting thought experiment, but it's rationally equivalent to saying "but what if little invisible unicorns are the ones actually experiencing things" or "what if we're all in the Matrix and it's a simulation" or "what if we're just an oddly persistent Boltzmann brain in an energetic nebula somewhere in the universe."

Without evidence, p-zombies are a plot device, not a legitimate rational launching off point for theorizing about anything serious.

Humans are conscious. We have neural correlates, endless recorded evidence, all sorts of second hand reporting which can compare and contrast our own first hand experiences and arrive at rational conclusions. Insisting on some arbitrary threshold of double blind, first hand, objective replicable evidence is not necessary, and even a bit shortsighted and silly, since the thing we are talking about cannot be directly shared or communicated. At some point, we'll be able to map engrams and share conscious experience directly between brains using BCI, and the translation layer between individuals will be studied, and we'll have chains of double blinded, replicable experiments that give us visibility into the algorithms of conscious experience.

Without direct interfaces to the brain and a robust knowledge of neural operation, we're left with tools of abstract reasoning. There's no good reason for p-zombies - they cannot exist, given the evidence, so we'd be better served by thinking about things that are real.

I would argue this is actually consciousness also. If (and yea, it's a big if) consciousness is an internal model/simulation of how we experience reality, then a simulation of a simulation is still a simulation.

If all civilizations that develop computation and simulation capabilities converge to the development of high fidelity simulations, then it's highly likely that they would create simulations of interesting periods of history, such as the period of time when computers, the internet, AI, and other technologies were developed. We just so happen to be living through that - I still put my odds of living in base reality somewhere above 98%, but there is a distinct possibility that we're all being simulated so that this period of history can be iterated and perturbed and studied, or some such scenario.

Maybe someone ought to start studying the science of universal adversarial simulation attacks, to elicit some glitches in the matrix. That'd be one hell of a paper.

Until 'they' restore the checkpoint and arrange your teams plane to fall out of the sky.

Now imagine an internal video game in a computer system that is being generated from the real world inputs of what it sees/hears/feels around it. You take outside input, simulate it, record some information on it, and output feedback into the real world.

Many people would say this isn't consciousness, but I personally disagree. You have input, processing, introspection, and output. The loops that occur in the human brain are more complex, but you have the same things occurring. There is electrical processing and chemical reactions occurring in the humans mind. Just because we don't understand their exact processing doesn't mean they are unrelated to consciousness. Moreso we can turn this consciousness off with drugs and stop said electrical processing.

As where I can visualize, use internal monologue, vividly recall my memories, etc. at will, by default I do none of the above, and my thoughts are opaque to me. For her, she almost exclusively uses her internal monologue when thinking, and her entire thought process is consciously visible to her. It’s entirely conceivable that other people might not have an experience of “consciousness” resembling anything like what my idea of consciousness is.

(I'm not arguing a particular position, but trying to figure out what to make of this. Also, this is based on what I've read, not personal experience.)

Were they unconscious, or are they now unable to remember what they did? I.e. amnesiac.

Nobody knows whether conscious experience is a requirement or not to "exhibit all of the external characteristics".

It's possible that the only way to get from state N to state N+1 is to include the consciousness function as part of that calculation.

A counter to this would be that a lookup table of states would produce the same external characteristics without consciousness.

A counter to that counter would be that the consciousness function is required to produce state N+1 from state N. The creation of the lookup table must have invoked the consciousness function to arrive at and store state N+1.

The thing we just don't really know is whether state N+1 can be derived from state N without the consciousness function being invoked.