Michael Engor points out that there are two types of problems related to human consciousness, these are what David Chalmers calls the easy problems and the hard problem. The easy problems are not called that because they are easily solved but rather because we can see how they may yield to future scientific research:
The easy problems are the sort treated routinely by neuroscientists. These are problems such as 'what is the neuroanatomical correlate of arousal?' or 'which neurotransmitters are associated with depression?' Of course, these questions are not easy in a scientific sense, but they are tractable by the methods of science, which are, for the most part, methodologically materialistic.
The hard problem is much different. There seems to be no way of solving it. It appears to be intractable:
The hard problem is this: why are we subjects, and not just objects? Why do we have subjective experiences? Descriptions of neurophysiology are all third-person - neurons do this, serotonin does that. Yet consciousness is experienced in the first person - 'I,' not 'it.' How is the 'third person' matter in our brains related to our actual first person experiences? The easy problems of consciousness relate to objective phenomena - neurotransmitters and action potentials. The hard problem of consciousness is qualitatively different - it's the problem of subjectivity. As Chalmers explains, the hard problem "persists even when the performance of all the relevant functions [e.g. neurochemistry] is explained."
In other words, we have certain subjective experiences which, if we are simply material beings, seem to be inexplicable. How, for example, does matter produce any of the following: self-awareness, appreciation of beauty, gratitude, disappointment, regret, resentment, a wish, a hope, a desire, a doubt, a belief, an intention? How does matter, a series of chemical reactions in the brain, result in understanding, frustration or boredom?
Engor points out that dualistic views are not without their problems:
Indeed, dualism has plenty of problems of its own, and dualists are honest about the problems. For example, how do the mind and brain actually interact?
This is indeed a puzzling question but it should not stop anyone from believing that they somehow do. After all, materialists believe that matter can warp space but I daresay no one knows how it does it. Nor does anyone know how gravity exerts its pull on objects or how similarly charged particles repel each other. The fact that we don't know how mind and matter can interact is no reason not to think that they do.
RLC