Why is the Hard Problem of Consciousness so hard? I found myself nodding at Wayfarer’s take on all this above:
“[N]o objective description of brain-states can convey or capture the first-person nature of experience. The kind of detailed physiological understanding of pain that a pharmacologist or anaestheologist has, is not in itself pain. Knowing about pain is not the same as being in pain.”
It’s really the difference between “explanation” and “experience.”
When we see a red apple and ask, “Why and how can this red apple be seen?” – and we want an explanation – then we can expound on all manner of material stuff (physics and neuroscience). That is, “red” is a certain wave length of light, and to see it requires retinal cone photoreceptors, a visual cortex, etc.
But if we ask the same question, “Why and how can this apple be seen?” – and we want an experience – then we must look at the apple and, assuming there is sufficient light and our eyes and brain are functioning normally, then we have a perception of a red apple. And the only way others can have this experience is for them to look at the apple too – where light is sufficient for them, and their eyes and brains are functioning normally.
Most notably: these conscious experiences – the perception of red apples – are private. No amount of explaining them physically and/or neuroscientifically can do them justice. The fact is, explanations of phenomena – no matter how accurate – are not the same as the experiences of these same phenomena. Someone else, although able to have their own visual perceptions, are unable to have mine. Similarly, only they can actually feel their own physical pain, while I can only feel mine. Again, we can explain how these perceptions and feelings occur via physics, neurochemistry and neurophysiology, but knowing about these explanations are not the same thing as having them (to paraphrase Wayfarer above).
And by the way, this is not to imply that there is something mystical going on here, or that consciousness is necessarily some sort of spiritual or immaterial substance. Maybe it's just a fact of biological existence that experience (consciousness) is private, whereas explanations of experience are (or can be) public. (?)
In any event: explanation is not experience.