The hard problem (Chalmers, 1996) is a conflict between current science and our experience, so one or the other must be wrong. That we consciously experience the world is hard for science to explain, but for most people it is simply self-evident, so why is it hard for science?
We see one light frequency as red and another as blue because neurons in our retina respond to them differently, but why is red this experience, and blue that one? Nothing in neuroscience requires the brain to produce experiences, so what creates redness and blueness? This problem is hard for science because in physical terms, there is no red or blue, just different light frequencies.
Imagine a scientist who knew all the facts known about blue from a monochrome screen, such as how neurons analyze blue light frequencies (Jackson, 1982). Yet if she then sees blue for the first time, it’s a new experience, so what does she now know that she didn’t before? This question is also hard for science because the facts of blueness don’t explain the experience of seeing blue.
Equally hard is that the experience of consciousness isn’t based on any specific brain function, of sense, thought or feeling (Block, 1995). For example, a person who can’t speak or move except to blink can still be conscious, as shown by locked in syndrome. Consider the thought experiment of the Islamic scientist Avicenna, of a man floating in a void with no awareness of his arms, legs, heart, or any body part, but he still knows that I Am, that I exist, even with no sensations. It is then hard for science to explain why the observer experience remains despite sensory-deprivation.
Visual cortex damage causes blindness but doesn’t stop consciousness, and even those born with no cortex evidence consciousness (Merker, 2007), so it can’t depend on a cortical area. No brain area has been identified as the seat of consciousness, as it persists even when the cerebellum, amygdala, hippocampi or cortex fail. Consciousness seems to be just there, in a way that can apply to any sense, memory, or feeling, so James concluded in 1892 that it 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).
Consciousness is the first fact because it precedes all other facts. As Kant concluded, a posteriori facts occur after the observer experience, and a priori facts before it (Kant, 2002), so I know that I observe but what I see is just a premise, or as science says, a theory. It follows that consciousness isn’t an a posteriori observational fact but an a priori experiential fact.
The hard problem assumes that science can’t accept experiential facts but actually it does, as fields like psychology and sociology accept them based on observer reports in questionnaires and surveys. Consciousness then is valid fact because subjects report it, and it is reliable because others report the same, so science can study it. Yet after centuries of discussion, the hard problem remains, as “The question of how matter gives rise to felt experience is one of the most vexing problems we know of.” (Brooks, 2020).
Why then are we conscious in a body made of matter?