Consciousness as the ability to observe refers to the phenomenon of consciousness not its function(Block, 1995), so being an observer doesn’t require any sense, thought or feeling. We need a visual cortex for visual consciousness but if damage to it causes blindness, consciousness doesn’t stop. No one brain area has been identified as the seat of consciousness, as it persists even when the cerebellum, amygdala, hippocampi or cortex fail, so people with locked in syndrome can still be conscious. The ability to observe is simply there in a way that doesn’t require any particular brain function. It can apply to any sense, memory or feeling, even those with no past precedent. James concluded in 1892 that consciousness is a fundamental fact:
“The first and foremost concrete fact which everyone will affirm to belongs to his inner experience is the fact that consciousness of some sort goes on.” (James, 2019)
In scientific terms, this fact is valid because anyone can confirm that they observe and it is reliable because others can repeat and report their experience. That we each observe differently is irrelevant to the fact that we do observe.
If I separate what I know from what I assume, I know I observe reality but I assume there is a physical world out there. We only truly know that we observe phenomena, not that they represent the world as it really is (Kant, 2002). The only thing we know with absolute certainty is that we observe reality. Everything else is just assumption, or as science says, theory.
In an observer-observed reality, an observer is needed for a thing to be observed. There must always be a viewer if reality is a view. Without an observer there is no first person, so we would say “It is red” rather than “I see red”. To say I see or I hear implies an observer. Scientists can observe this or that fact but the ability to observe is the first fact because without it, there are no other facts. Science needs observation because there is no knowledge without a knower, so it must accept the first fact because it can’t exist without it.