The Mystery of Consciousness


How does the inanimate matter inside of our heads produce an experience? We all have this sensation of ‘being there’, the ‘lights are on’ in a way that we tend not to ascribe to other kinds of things. If we think about chairs for instance, very few of us suppose that chairs are having an experience, even though science tells us that chairs are made of the same basic components as humans. Chairs are merely combinations of atoms, albeit different combinations to ours, but still just atoms. There isn’t any unique feature of the individual atoms that comprise our bodies, no vital spirit giving life or consciousness. The relevant difference between us and a chair is that our atoms are arranged in a sufficiently complex manner so as to allow for the flow of information. Does this information flow and information processing account for consciousness? If so, are other information processors having conscious experiences? Most of us attribute consciousness to animals which are sufficiently similar to ourselves, however are hesitant to extend it to other information processors. Insects and plants engage in information processing of a kind, but we rarely consider them to be more sentient than the chair mentioned before. How about the great information processors that we created? Computers are capable of remarkable feats of information processing, that baffle us, however once again, very few of us grant them any subjective experiences. If it isn’t information processing that gives rise to consciousness, then what does? And can an explanation be found by using our traditional methods? A scientific explanation of phenomenal consciousness would be a remarkable achievement in human intellect, perhaps an achievement which will remain unattained.


What is consciousness?

In order to give a valid explanation of consciousness, we need to attempt to define it. The word consciousness has a number of meanings, some more mainstream than others. When a person is asleep, they are often considered to be conscious in a limited sense through dreaming. A person may be labelled as unconscious if they are unresponsive following the excessive consumption of drugs or a blow to the head. While sitting an exam, it is advisable to be conscious of time. Here, the word conscious could seamlessly be swapped with the word aware. Then there is a deeper level at which people talk about consciousness. The combination of sensory inputs, the ability to process information, thoughts, memories, emotions, beliefs and sensations are often considered to be the contents of consciousness. Interesting though these concepts may be, they aren’t what we are talking about here. We want to explain a more fundamental feature that is present in all of these concepts, and by extension all possible concepts. It seems that this is a point of division in the field. Many thinkers (Dennett, Churchlands, etc) believe that the combined explanations of these concepts would be an explanation of consciousness. However a number of philosophers find this unsatisfactory and believe there to be another problem which is being skirted by explanations of this kind. It seems that while these concepts would need to be accounted for to fully explain consciousness, they aren’t sufficient to explain it. There is something more about consciousness that needs explaining, the mysterious subjective nature of experience. Why should there be a subjective experience to any of these contents? The mere presence of these contents is insufficient to explain how and why they are experienced subjectively. The contents seem to be delivered to the cognitive subject in a way that the subject has an experience of them. There is such thing as a thought about a tomato and this thought has a corresponding neuronal activation pattern (brain activity) that can be studied scientifically, but there is also ‘something it is like’ for a cognitive agent to be having a thought about a tomato. It is the ‘something it is like’ that we are concerned with here (Nagel, 1974).


The Hard Problem of Consciousness

The philosopher David Chalmers came up with the term ‘The Hard Problem of Consciousness’ to draw a theoretical line in the sand between it and the so called ‘easy’ problems of consciousness. This wasn’t to downplay the difficulty of solving the ‘easy’ problems, which are sufficiently hard in their own right, it was to highlight the difficulty of the hard problem. He framed it as the mystery of how physical processes in the brain seem to give rise to a subjective experience (Chalmers, 1995). The concepts mentioned in the previous paragraph fall under the category of the ‘easy’ problems as they are objectively observable. The brain can be studied and the relevant concepts can be mapped onto specific activity in the brain. The ‘hard’ problem however concerns itself with why this activity should deliver an experience to the cognitive subject whose brain is engaging in the activity. This can lead us down another path, the path of trying to explain where these experiences are delivered to the self and by extension how do we locate the feeling of the self. The self is the feeling of being a distinct, separate entity, with a private mental world. Is the self just an illusion? Contemplatives throughout the ages have claimed that through extensive meditative practice it is possible to have experiences of selflessness, whereby they are able to merely observe the contents of consciousness. From such a position, all that remains is the subjective feeling of consciousness. This sensation of consciousness could be present even in the absence of all of the contents that we typically feel tied to. This is one way to visualise the difference between the ‘easy’ and ‘hard’ problems of consciousness and could possibly cause some philosophers to reconsider their dismissal of the ‘hard’ problem. The ‘easy’ problems are concerned with explaining the contents, while the ‘hard’ problem is concerned with explaining the raw feeling of subjective consciousness that lingers on in the absence of the feeling of the self (Harris, 2014). Regardless of whether this form of introspection is useful or not, the ‘hard’ problem remains. There is nothing about the physical structure of the brain, even in full swing, that would suggest an intricate world exists within. Even if we were able to ascribe every physical event in the brain to the relevant mental content, we wouldn’t have anything to say about why the event delivers a subjective experience. Why should neuronal firing pattern α, which delivers the mental content α, cause a subjective experience? Where in this hive of activity does subjectivity arise? What is it about this special combination of matter that causes an experience of the information being carried by it? This is the hard problem of consciousness and any valid theory of consciousness must be able to solve it.


Can Subjectivity be Objectively explained?

Scientific inquiry relies upon objectively measurable quantities. The science of the ‘easy’ problems of consciousness is quite well advanced. Many of the sensory inputs have been accounted for in terms of the relationship between the physical processes in the world and the subsequent representation of these processes in the relevant sensory systems. Sound is received by the eardrum as vibrations in the air, caused by some physical vibration of an object, these vibrations subsequently cause the eardrum to vibrate at a relative frequency. This vibration is coded into neuronal firings. This is the ‘easy’ part of the sound problem, then the magic happens, a cognitive agent has a subjective experience that he calls sound. The ‘easy’ problems of consciousness are scientifically observable phenomena. They are simply things that are happening in the world, objectively available to anyone with the sufficient technology to view them. The subjective nature of conscious experience however is not objectively observable. It doesn’t matter how advanced the technology, or how comprehensive the neuroscience/cognitive science is, we can’t observe anyone else’s subjective experience. To do this would require more than a mind reading device but a mind experiencing device. It could be argued that a completed theory of neuroscience/cognitive science combined with a perfect brain scanner would be a mind reading device. This device may produce output that directly matches the exact mental events happening in the subjects mind. However this still would not be an observation of the subjective nature of this person’s mind. The person isn’t experiencing a series of outputs, or even a string of thoughts, they are experiencing the totality of their conscious experience, moment to moment.

This problem goes to the heart of epistemology. What can be known about the nature of consciousness and how can it be known? It seems that no method of inquiry that relies upon objective observation can locate the subjective nature of consciousness. Is it more broadly true, that the objective can never explain the subjective? Possibly the only way that subjective experience can be explained is with reference to subjective experience and that furthermore one can’t have subjectivity or consciousness explained to them if they themselves lack the phenomenon. The only method we have for truly knowing whether a system is conscious is by being that system. We can’t rely on it’s responsiveness to stimuli, as many things that are likely to be lacking consciousness can react to the world around them. We can’t even really rely upon self report of consciousnesses. Most of us assume that everyone else has conscious experiences, but strictly speaking we have no way to be sure. More specifically, I have no way to be sure that anyone else is having conscious experiences in the way that I do. This can be illustrated by simply imagining a sufficiently well developed robot, that could pass the Turing test and hold a conversation and behave appropriately around people. This robot may be capable of speaking incisively about consciousness, without actually having consciousness itself. Perhaps it is relying upon a comprehensive database which includes all of the appropriate things to say about consciousness. If we can’t tell whether the robot is conscious, then strictly speaking none of us can be sure whether any other people are conscious. This would also require explaining why it is that you are different to everyone else and possess consciousness in the first place. The chances are that this is nonsense, but it is a useful example to illustrate the difficulty of locating subjectivity from an objective viewpoint.


Science and Consciousness

At this stage it would seem appropriate to survey the predominate scientific attempts to explain consciousness and see if they stack up against our requirement of solving the hard problem. “Consciousness thus appears unique and, to many minds, beyond scientific explanation. Or anyway, beyond purely physical explanation. Consciousness, it has been argued is essentially a subjective phenomenon, accessible only to the creature that has it, while anything that is truly physical – one’s brain activity for example is doomed to be objective in nature, that is, to be accessible to many people from many points of view” (Churchland, 1995). Churchland acknowledges the difficulty of explaining a subjective process in terms of objective phenomenon, however holds high hopes that science can overcome these difficulties. It is true that science has answered questions that once seemed beyond the scope of human observation, the location of the Earth in relation to the stars was declared by Ptolemy as inaccessible from our perspective. More recently, many people believed there to be some vital spirit giving life to creatures such as ourselves. With the aid of a thought experiment this was a well subscribed to belief. Suppose we were shrunk down to the size of an atom and placed inside the human body, it seems that we could travel around the various compartments of the body without coming across anything that would resemble life. There would be no reason to associate the strange structures you encountered and the activities they were engaged in, with the living being that you were internally exploring. The claim then goes that with both of these examples, it was merely a lack of imagination that restricted people from grappling with the true location of the Earth or with modern molecular biology. These questions have since been answered, so why shouldn’t a science of the future explain consciousness in the future. Well, the stark difference between these examples and the difficulty of consciousness is clear. The location of the Earth and the intricacies of molecular biology are both objectively observable phenomena, whereas the subjective experiences had by conscious creatures are not.


Previous research in neuroscience has suggested that consciousness may arise from certain oscillations in the cerebral cortex, which become synchronized as neurons fire 40 times per second (Crick and Koch, 1990). This may be useful for explaining how different inputs of a single object (its colour and shape, for example), are unified into a coherent whole. In this theory, two pieces of information become bound together precisely when they are represented by synchronized neural firings. Fascinating as this theory may be it still only refers to the easy problems and says nothing about why this synchronization of neuronal firing should deliver a subjective experience. Would the researchers suppose that a perfect replication of this would produce consciousness?


Similar complaints can be made about the work of Dennett, who puts forth a model of consciousness involving multiple layers. These layers are the result of inputs to the brain which have arrived at different times, which gives rise to a successive narrative prone to change as each input takes forefront. Thus it is analogous to ‘multiple drafts’ of a story. Both Chalmers and the philosopher John Searle take issue with Dennett in similar ways. Chalmers believes that Dennett addresses only the ‘easy’ problems of consciousness and has nothing to say about the hard problem of subjectivity. This seems a valid criticism, Dennett’s ‘multiple drafts’ theory may be entirely correct as to how information is integrated and processed by the brain, however it doesn’t explain why well explained integrated information should produce a subjective consciousness. Searle, an old sparring partner of Dennett’s is more abrasive in his response:

“Dennett denies the existence of the data. To put it as clearly as I can: in his book, Consciousness Explained, Dennett denies the existence of consciousness. He continues to use the word, but he means something different by it. For him, it refers only to third-person phenomena, not to the first-person conscious feelings and experiences we all have. For Dennett there is no difference between us humans and complex zombies who lack any inner feelings, because we are all just complex zombies” (Searle, 1995). It seems that Searle’s main criticism is similar to that of Chalmers in that he accuses Dennett of ignoring the ‘hard’ problem of consciousness. The subjective, ‘what it is likeness’ of conscious experience. Dennett is happy to go along with the concept of the human zombie, a being that is for all intents and purposes identical to a human, in that it is capable of all the same thought processes and behaviours but it lacks any subjective experiences. To swap places with the zombie would be synonymous with the ‘lights going out’.


The neuroscientist Sam Harris follows Chalmers down the path of the intractability of the ‘hard’ problem of consciousness by scientific methods. “The idea that consciousness is identical to (or emerged from) unconscious physical events is, I would argue, impossible to properly conceive—which is to say that we can think we are thinking it, but we are mistaken” (Harris, 2011). The very idea of unconsciousness being involved in consciousness seems paradoxical. The two concepts seem entirely antithetical to one another. Either an object has consciousness or it doesn’t. The lights are on, or they are off. There is nothing to be gained by postulating a gradual increase in consciousness from primitive to advanced, if we want to actually explain consciousness. The important step is from no consciousness to some consciousness, and it seems that this change would have to occur in one increment.



A science of subjectivity, a theory of consciousness, would have to demonstrate in objective terms how something which is unconscious can create something which is subjectively conscious. A feat which science, as it is currently understood, has little hope of achieving. We may be left with the unsatisfactory conclusion that consciousness, like space, time and matter is a fundamental feature of the universe in which we live.




















Chalmers, D. (1995). The Puzzle of Conscious Experience. Scientific American, 273(6), pp.80-86.


Chalmers, D. (1996). The Conscious Mind. 1st ed. New York: Oxford University Press.


Churchland, P. (1996). The engine of reason, the seat of the soul. 1st ed. Cambridge, Mass.: London.


Dennett, D. (1991). Consciousness Explained. 1st ed. New York: Little, Brown & Company, pp.1-65.


Harris, S. (2004). The End of Faith: Religion, Terror, and The Future of Reason. 1st ed. New York: The Free Press, pp.204-223.


Harris, S. (2011). The Mystery of Consciousness. [Blog] Sam Harris. Available at: [Accessed 20 May 2017].


Harris, S. (2011). The Mystery of Consciousness II. [Blog] Sam Harris. Available at: [Accessed 20 May 2017].


Harris, S. (2014). Waking Up: A Guide to Spirituality without Religion. 1st ed. New York: Simon & Schuster.


Searle, J. and Dennett, D. (1995). ‘The Mystery of Consciousness’: An Exchange. [online] The New York Review of Books. Available at: [Accessed 16 Jun. 2017].