The phrase "Hard Problem of Consciousness" was coined in 1994, and is the subject of no small controversy. It is something that I have attempted to create a satisfactory explanation for over most of my life, to constant frustration. I am writing this article now, not because I have solved the problem, but because I have failed to solve the problem enough times that I am confident I can clearly describe its exact nature. It is in this description of the very nature of the problem that many authors begin to introduce confusion; through a careful propositional structuring of my argument, I intend to avoid this error, and to then convince the reader that my specific interpretation of the hard problem is both the only reasonable belief, and intrinsically, fatally flawed. In doing so, I hope to enable the reader to share in my frustration as it concerns this unsolveable problem.
Defining consciousness is itself no easy task. The term has been used by various authors in various ways, and each of these definitions introduces additional ambiguity. To define exactly what I mean in referring to consciousness, we must first reach an understanding of the scope of the term. Consciousness, as I will use the term, appears to be closely related to the human brain--and so I say that its scope, as far as we are concerned, is limited to complex systems. A complex system may be described as any sufficiently large set of physical objects that interact frequently, and that have been designed, either by intention or by circumstance, to perform some task. In the case of the human brain, that task is of course reproduction and survival. To accomplish that task, the brain must receive sensory information, process it, and, based on the result of that processing, control the body. This process can be modelled at the highest level in psychology, at a lower level in biology, and at the lowest level by physics. At the lowest level, the brain is acting in a (excluding quantum nondeterminism) deterministic manner, defined by the basic interaction of carefully arranged molecules. It is the opinion of some authors that this description of the brain minimizes human agency. I reject this--human agency is itself a product of the process I have described, and cannot be minimized by a description of its origin. The reason for this concern can likely be ascribed to the long-standing belief in some form of soul, or other intangible, immeasurable entity separate from the mechanical processes of the brain. The brain evidently determines behaviour.
The soul, spirit, or anima is typically taken to be the entity which contains or defines a person's individual nature. The soul is necessarily quantized, perhaps being able to be created or destroyed but never subdivided, and non-fungible, each being unique in some form. While brain cells may die and the body may change, the soul is a persistent, non-mutable identity. The exact purpose, origin, and location of the soul varies by interpretation. Whether it is responsible for will, or godliness; created at conception, or repurposed, from some prior incarnation in rebirth; or whether it is located in the heart, or in the pineal gland--the soul is a concept that has been invented by multiple independant cultures over human history, and is deeply important to the philosophy and religion of a significant portion of those alive today. The specific reason for the prevalence of a belief in the soul is easily ascribed to humans' perception of ourselves as conscious, and a desire to understand the origin and nature of that consciousness. The soul evidently determines behaviour.
If the brain adequately explains human psychology, if thoughts are merely specific patterns of neurons firing, it seems that there is no place for the soul in modern science.
Consider reading my essay concerning analogies prior to continuing this article. Philosophers, and those experiencing existential crises, have frequently referenced a set of thought experiments concerning a common theme: that the consensus material world may not be real, or, more precisely, that it may not be the base stratum of objectivity. Possibly the first record of this concern was René Descartes's evil demon argument, which posits that one's senses may be an illusion created by some malevolent agent--an all powerful demon capable of inducing to you any sensory perception he chooses. A more modern phrasing is the brain in a jar scenario. In this case, some future technology enables the brain to be suspended and kept living inside of an artificial environment. This brain is precisely stimulated by computer, generating a simulated perception of a reality, which could be entirely different from the one the brain is located in. Other, analogous arguments include the Boltzmann Brain, the simulation hypothesis, and certain interpretations of hell, heaven, and purgatory.
Consider these arguments. They are irrefutable--we must live as though they are false, but we cannot prove that they are. We can, however, take one important point from them: regardless of what specific reality we may interpret, and what specific reality may truly exist, it is evident that we have an acute sense of our own existence as some form of entity; it is unclear whether we are being tricked, but it is clear that there is something to be tricked.
Suppose we had access to some form of device capable of precisely measuring the exact state of every neuron and neurotransmitter in some test subject's brain. Suppose that we could record this data over a few minutes, and run the tape in reverse, observing the cause of every effect. We would introduce some stimulus to the subject--say, a red cube--who would have been instructed to describe what he sees. We would observe his statement, "I see a red cube," and end the recording. We begin analyzing the data. First, we note which neurons were responsible for signalling the muscular activity required to create speech. We name this set N0. We record the set of all neurons whose axon terminals had interaction with any neuron in N0, and name these after the neuron with which they interacted. We iteratively perform this regress until we have a tree structure which contains every neuron involved in the signal processing from observation to statement.
The question is as follows: would, at any point in the recording, a neuron demonstrate behaviour not in line with the action potential model? Specifically, would a neuron ever fire without a measurable physical cause? In the case where this does occur, we have observed what appears to be something very strange--a physical effect without a physical cause. In the case where this does not occur, we have observed something perhaps stranger.