According to supernatural conceptions of the self, we’re not identical with the brain since we consist of a spiritual, immaterial and thus seemingly immortal substance. That substance portends an apocalyptic end of all of nature by a hidden, transcendent reality that’s thought of as the abode of the universe’s personal creator. The modern word for “spirit” is “consciousness,” since consciousness, too, seems like a ghostly presence, an invisible homunculi within the head. According to the science-centered view, though, the self is a congeries of programs computed somehow by the embodied nervous system; at any rate, the self is a natural thing or process, operating under physical laws. The opposition between these two conceptions sets up either the personal self or the natural body to be interpreted as an illusion subordinated to the other’s corresponding ontology.
But all of this is oversimplified. There clearly is a materialistic, animalistic, embodied self just as clearly as there is a subjective, personal, and thus potentially noble or transcendent thing as mind.
The Self’s Origin in Higher-Order Thought
Here’s how I see mind arising from mechanisms operating in the body. The brain evolved as a hodgepodge of modules, which are independent, specialized subsystems that carry out specific functions. Most animals receive inputs from one or another module and their training takes over, automating their behaviour. This is to say that they lack personhood, which is the awareness of being a self that processes perceptual inputs and can freely decide how to respond. Our species adapted to life after the eons in which dinosaurian might made right, by developing a capacity for high intelligence that’s generated by the cerebral cortex. Our Mesolithic and Paleolithic ancestors found themselves able to categorize phenomena to a high level of abstraction and to systematize their communications using the technology of linguistic symbols and rules. Instead of reacting automatically to stimuli, they could reflect and prepare their response, learning the most efficient techniques and preserving that information for future generations.
Consciousness arose as a special kind of higher-order thought. Picture a primate flooded with information from its environment which it could now customize by categories and access at will, thanks to its cerebral cortex which acts as a brain within a brain, detaching the emotion and motor centers from the environmental cues so that the primate’s behaviour needn’t be slaved to genetic programming. The primate could always investigate the outer world with its paws and outer senses, but now it could also organize the flood of data within its head. In short, it could think about its thoughts. For example, the primate could think roughly, “This pain feels bad, but it would be best not to wince, to avoid looking like a weakling.” Instead of being concerned just with modifying its outer environment, the sapient primate learned how to develop its cognitive capacities. It did so by rational detachment and by linguistic abstraction, which allowed for higher-order thoughts, which in turn enable the species to thrive and thus to continue to practice thinking in its free time.
But what is the self that is accomplishing these cognitive feats? There was no otherworldly monolith that intervened in the Stone Age and miraculously transformed animals into people, as in Kubrick’s film 2001. Instead, I think we should picture those early intelligent primates as being terrified of their cognitive powers and as inventing the self to manage that fear. Specifically, as their reasoning center gradually disentangled itself from the older neural subsystems, with the advent of their brain within the brain, and as those forerunners became more sophisticated in managing their thoughts, they would still have been exposed to fear of that enclosed inner space.