>We're pretty clear on the distinction between a conscious and an unconscious human.
You are using unconscious as a synonym for asleep, which is not the same thing as having no conscious experience due to dreams. We are clear on the distinction between a dead human and an alive human however.
Unconsciousness is not the same thing as sleeping.
Im not sure where sleeping lies but it's probably somewhere between the consciousness and unconsciousness depending on which phase of sleep you are in and perhaps whether you are lucid dreaming.
Which is to say, this is still a mystery but it still isnt a definitional problem it's a regular old scientific mystery.