On the three body problem, I withdraw while you explore the subject with Doctor Stochastic.
You assume most people are conscious because they have language. For those who do not have language, you assume they are conscious because "they have language capability". An interesting assumption, but at least in the case of the deaf, a false one. I specifically asked, in the case of the deaf, how you would classify them if they were not taught language. This is not a trivial or trick question, because prior the the invention of sign language, "deaf and dumb" people were warehoused with the profoundly retarded. By the way, are the profoundly retarded conscious?
The profoundly retarded are conscious in my view - as are the ones who have never attained the ability to communicate.
In my view the brain is a transmitter/receiver for the spirit and not the spirit itself. Thus, in the same way a broken radio does not mean that the "signal" is impaired - a broken body or brain does not mean the spirit is impaired.
In fact, I would not at all be surprised to discover that the very ones we consider to be mentally retarded in this physical realm are not far better developed in the spiritual realm - simply because their worldview might not be as tainted by physical experiences.
So is it the physical form of the brain that gives it that capacity, or is it simply axiomatic that humans are different from other animals?
Are apes having sign language conscious? Chomsky says no, and his views are golden on this forum. ;^)
Is there some test, even a hypothetical one, that could settle the issue?