Updated 3 Nov 2021
Back in the day, thousands of years ago, primitive people made no distinction between consciousness and physical presence, even trees and mountains were assumed to have spirits. We knew very little about what our vital organs did. The heart was unique in being vigorously active throughout our life and stopping immediately when we die. It was a reasonable first guess that the heart was the source of our vitality, our "alive-ness". Nobody realised that the blood circulated, the heart was thought to push in all directions equally, spreading vitality with every pulse.
People seeking the seat of active consciousness assumed that it too lay in the heart, and even cut them open in the search for a "homunculus", a miniature human supposed to be the conscious self within the body. Others thought that the vital ingredient left through the lungs, next to the heart, in our last breath – "spiritus" is a Latin word for breath. Whatever it was, it was thought to be "atomic", an indivisible thing or atom of being in its own right, a spirit or soul capable of taking on a life of its own, travelling beyond the living body and of surviving its death.
Long before we learned that consciousness resides in the brain, the next great step in understanding was taken by Eastern philosophers. Around five hundred BC, thinkers such as the Taoist Lao Tzu and Siddhartha Gautama, better known as the Buddha, realised that the primitive idea of the atomic self was all wrong, we simply don't have one. The mind just processes information and builds an image of itself and its body to help it understand and control the world around it. As that image flickers in and out of activity, we gain and lose consciousness. On reawakening, the self must be rebuilt from memories and the latest sense impressions. We recreate our selves incessantly, fooling ourselves every waking moment that our existence is continuous day after day.
This rather begs the question, what exactly is fooling itself into believing that it is a "self"? If there is nothing there, then there can be nothing to fool itself into believing anything, that would be absurd. So just what exactly is being fooled? The mystic is tempted to see this as a direct refutation of the materialist position – there must be a self or something like it, in order to delude itself. Perhaps that is the role of the soul or spirit. The Buddha tended to adopt the word "dharma" for it, which some loosely translate as our "Buddha nature"; all in all, little more than a labelling exercise for the unexplained. But things are not quite that simple. One Indian guru I read described it as "the enjoyer of the self" and ascribed its identity to Brahma (effectively, God).
We can build a scientific, materialistic theory of a physical brain with memories and sensors and processing and control circuits, then set it processing information so that it seeks to understand and control the world around it. To help it do this it builds a model of an identifiable or "atomic" self and even builds the belief that it is that self. The latest work on artificial intelligence is even beginning to nibble away at building that model of the self. But it is not yet clear how everything fits together. In Seeing Myself (Robinson 2017), Susan Blackmore suggests that "It is models of self that are conscious, models of self that experience...". However I would suggest that, by contrast, the model of the self is rather just one part of the brain processing, information to be experienced rather than the entity which experiences it.
All the old mental elements, such as memory, personality and self-reference, remain necessary ingredients. Indeed, the many enduring qualities of these and other elements of brain structure would suggest that in these respects the self does endure from day to day after all. It persists for a lifetime but, unlike the primitive one that we once believed in, it is tied wholly to the brain which sustains it.
This idea of the self as an information construct has been increasingly supported by modern science and is now widely accepted in the West, as well as the East. But there are some minor variations which cause a good deal of confusion. Because the conscious model is just a processing construct, a constantly-changing block of information, people are fond of saying that it still does not, therefore, exist. In this sense, the relatively permanent parts of the self – memory, structural form, etc. are ignored. Frankly, that is like arguing that a piece of software does not exist until you run it on your computer. The technical term for this is an "instance" of the software, while the code itself very palpably exists in the computer's long-term memory. There is never more than one instance of any self, so the distinction becomes one of vapid pedantry. One might also enquire as to why AI researchers are beginning to develop the basic elements of the self, if no such thing exists.
This analogy with software (if it is an analogy) draws out another property of the modern idea of the self – it is in essence information. It draws on the brain as a kind of substrate to store and process the information, much as computer hardware stores and processes software, but it is quite distinct from the physical substance of the brain. That is why we can lose consciousness while the brain still exists unharmed, as when going to sleep. Many people who ought to know better still talk of the physical brain as a conscious thing and try to draw conclusions about the structure of the self from the structure of the brain. This is absurd, it is like arguing that a computer has a central processor, an input/output control subsystem and a reset switch, so the software it runs must be like that too. Oh, how I long for my computer's software apps to have a reset switch! No, the structure of the brain is a poor guide compared to the information encoded in its electrochemical signalling. The brain itself is not conscious, for that we must turn to the meaning carried by its ever-changing patterns of activity.
This brings us onto the other important confusion over the modern approach, though it is a much older one. There is no hint in the scientific model just described, as to what the busy brain construct, the self-model, might "feel like" to itself.
Zombies are often invoked to try and clarify this issue. But there are two kinds of zombie which people discuss, and sometimes confusion between them leads people astray. First, there is the utterly "mindless" zombie. It acts only through the wholly unconscious workings of the brain, such as coordinating walking or grasping at an object it sees. This is not unlike the current state of AI systems. But some philosophers propose an "intelligent" zombie, capable of rational thought; it is to all appearances indistinguishable from ourselves and can pass a Turing test without effort. Does its mind include a model of the self? Certainly, or it could not relate its thoughts to its senses and actions. But it has no inner experience, no "enjoyer of the self", it remains an unconscious machine. The question is, can such an intelligent zombie exist?
The answer to that depends on your beliefs about the nature of consciousness. According to IIT, if the complexity is there, be it a humanoid zombie or an AI system or an octopus, then consciousness arises. Any suggestion of such mental complexity without consciousness, then begs the question as to what the difference between the intelligent zombie and the sentient being must be. Do we have any evidence one way or the other, for or against its existence?
I would argue that it does imply one major behavioural difference. Ask a human and they will expand on their own consciousness at length. It guides much of their life. Ask an intelligent zombie and they will have no concept of what you are talking about. Yes, you could explain what you mean and something might possibly stimulate them to pretend they were conscious too. But, just as a blind person cannot convincingly bluff that they are sighted, nor a deaf person that they can hear, so too an intelligent zomble could not fool anybody into thinking they were conscious. A few parlour tricks perhaps, but no more. I am constantly unsurprised by the way really quite sensible and balanced people reject this analysis with much heat and little reason. The anthropomorphic arrogance that it is restricted to biological, or even human, brains remains pervasive among those who should know better. Unsurprised? yes, that's human nature for you; the atheistic materialst seems particularly blind to their own blindness when it comes to brain hardware.
No, there is something which fires up consciousness – sentience – in any sufficiently complex information processor, you and I and our kind are far from alone. What might it be? Other than finding it literally in our faces when we wake up every morning of our lives, can we say anything else about it?
What makes redness red, what makes pain painful? What, indeed, it is like to experience being an apparently atomic self? Such a sense impression is called a quale and they pour through us in an endless stream of qualia to create our subjective conscious experience. Where do qualia come from? How do we, the experiencers or enjoyers of those qualia, fit in to the picture? This question is so intractable to the materialist way of thinking that it has become known as "the hard problem" in the philosophical theory of mind. Frankly, we have made no real progress in the last two and a half thousand years. We still have no idea what it is that makes information at a certain level of complexity suddenly start consciously experiencing itself. There is an ancient mystical suggestion that it is the qualia stream, rather than the information it embodies, which is the conscious entity. Might this point the way to some other, independent level of being? I explore this further in Towards a Theory of Qualia and The Three Levels of Being.
I have argued that our idea of the self has changed over the years. So when somebody claims that the self does or does not exist, or is or is not a figment of the imagination, they need to be sure of the context for their judgement and the kind of self that is implied. The old atomic self, the new informational one, the mysterious enjoyer, with or without the physical brain, long-term memory function and/or the mystery of consciousness. In the end, whether or not the self exists depends very much on what you mean by "your self".