Consciousness has, since humans first contemplated the issue, been a confusing concept which results in endless debates. Consciousness has variously been associated with ‘soul’ and ‘spirit’ in earlier times and ‘thought’, ‘self’, ‘cognition’, ‘perception’ and other cognitive processes in more recent times. Typically, a scientific discipline, religious or philosophical position, medical requirement or folk interest, selects some property of consciousness of greatest interest to them and then define consciousness by that one property alone. For instance, in medicine the greatest need of the concept is to determine the normal state of consciousness and return a patient to within that normal spectrum so ‘coma’, ‘persistent vegetative state’ and other variations on normal functioning form a loose scale with ‘normal’ being the desired point on that scale, usually defined by the state that was normal for a particular patient before some kind of medical event altered that state.
Taking the most general view possible, we note that in the living being consciousness serves the brain, that is, it is a process that interacts with other brain functions.
Science contrasts with folk interest, philosophy and religious concerns in that science tries to define only the objective indications of consciousness whereas the others mentioned are more likely to begin with the subjective experience of consciousness and work outward from there. Neither approach has ever reached the other side. Objective approaches cannot differentiate between a highly advanced automata having no inner life or experience and only responding by memory or learned response and subjective models have never managed to make a flowchart for a subjective experience so that perceiver and the perceived are independently accounted for in a consistent and convincing way.
A further dimension to consider is the question of who has consciousness, particularly when contrasting humans with non-human species. Even if we allow consciousness for our primate cousins, do we include, for instance, bacteria as being conscious to some degree? Is language a prerequisite? Is the Earth or the entire universe conscious as is popularly believed by many? Where is the border between those species that are conscious and those that are not or, indeed, between the adult human and the freshly fertilised egg: at what point does consciousness begin and is it continuous?
Is it possible, then, to define, characterise or describe consciousness in a way that is consistent with all the above approaches? Considering that religions include disembodiment of consciousness, artificial intelligence researchers believe that the brain is just nature’s way of making a computer and so is not essential for consciousness; and the many cognitive and biological approaches, this would, at first glance, seem to be somewhat unlikely.
Taking the most general view possible, we note that in the living being consciousness serves the brain, that is, it is a process that interacts with other brain functions. The brain is the one organ of the body that cannot be momentarily removed or disabled and consciousness continue. The brain is an organ that became important in multi-celled species and its role is to serve the body, to be a tool the body can use to achieve specific survival ends. The body, whether multi-celled or single, has the sole identifiable purpose of preserving life both individually, colonially and generationally. We can now reverse this regressing and see that life itself is identified at the cellular level by life preservation processes such as metabolism, self-repair and homeostasis, colonially by responding to the environment including conspecifics, and generationally through reproduction.
Increasingly, sophisticated species achieve these same basic goals through a variety of biological tools made up of specialised organs, limbs, and inherited information. The brain is one of these organs and consciousness is one of the tools the brain utilises to achieve those same ends.
Subjectively, and staying on this same theme, we ask what it would be like if life itself could rise up through the body, via the brain, and speak with us directly. This is, of course, what consciousness is. Just as each of the organs behaves in a particular way when alive, the brain is a conduit for life itself and shares the same basic functions identified above. If we accept that each of the cells of the human body and brain are independently alive even if they cannot survive independently, and that the human is also alive, then we must accept that the organs are also in some sense alive as they certainly can die. Just as the alive body moves, the alive heart beats: the alive brain thinks, perceives, initiates behaviour and harbours life in the form of consciousness.
The weakness of this argument is that we don’t know what life actually is beyond the behaviour of living organisms. The strength of this argument is the smooth transition between the first living things and the highest of most advanced forms of consciousness as seen in humans, they all being expressions of what is essentially the same thing. Subjectively, the self we experience is the latest ember of a living fire ignited with the first spark of life some billions of years ago here on Earth, an idea nicely dovetailing with religious conceptions of a self, shared with all others and the living planet that, like the cell or body, is the vehicle capable of harbouring the life whose original source we all share.
Consciousness, like the emotion ‘love’, life and the physical phenomena of ‘time’ and temperature, has the unnerving property of disappearing when examined at the finest scale. Further, each of the properties we can associate with consciousness (or life or time or temperature or love) can independently be removed for some interval and the phenomena being examined remains present.
Each of the properties of consciousness can also be emulated independently, such as in computers, but not life or consciousness itself. That consciousness has the same broad functions we ascribe to life (e.g., homeostasis, self-maintenance, response to the environment) should be of no surprise. The ‘self’ and our self-perception are an inevitable consequence of a cognitive manifestation of homeostasis and so we can expect some kind of analogue in all species with brains, but even for those without brains, homeostasis is a feedback process by which life has some awareness of its own existence.