Many people, for a long time, have thought that the function of consciousness was thought, all thought or just all rational thought, or control of action and decision making. Talk of the conscious mind and conscious will than imply to particular sort of consciousness. When thought and control turned out to be largely or wholly unconscious, there appeared to be no function left for consciousness. It might be just an interesting by-product of mental activity but not important to it. We could be zombies and it would make no difference. But no - just because consciousness is not the star does not mean it is not in the play. Just because it is not perception, cognition or action does not mean that it is not involved.
David Chalmers is probably the most prominent dualist philosophy today. He coined the notion of the ‘hard problem of consciousness’. It is explaining the phenomenal, the subjective ‘what is it like?’ of consciousness. He has put forward an argument based on a thought experiment: there could be physical duplicates of human beings that behave just like us but lacking qualitative experience/consciousness and because we can conceive of these ‘zombies’ they must be logically possible and because they are logically possible it follows that qualia and feeling are not wholly physical. Thought experiments are always suspect. I personally cannot conceive of someone behaving like a normal conscious human while lacking consciousness. That is ludicrous. Nor does conceiving of something make it logically possible. I can imagine flying without wings or effort but that does not convince me that it is possible. And finally why would logically possible zombies have to be other than physical? Every step of this argument is not convincing to me. Lets try the equally weak counter thought experiment it is not possible to conceive of a non-physical process therefore non-physical processes are not logically possible - consciousness is a process and therefore it is a physical process. Thought experiments are only as good as their premises. If you start with a dualist premise, you can come to a dualist conclusion and if you start with a non-dualist premise, you can come to a non-dualist conclusion.
So it seems that the problem for the dualist is the phenomenal experience, the qualia, and their seeming non-compatibility with a purely material brain. Not to be obtuse, I wonder, what would the experience of the world be expected to feel like in a physical brain? How would the nature of surfaces be rendered? How would we know how much light they would reflect? What wavelengths of light they absorb? How smooth they are? Etc? If someone has a better way than the one we experience normally, than they should say so. The evolutionary process has given us a very good way to experience the world, and we should not be surprised that it is impressive. We do not have a clear picture of how it is done but I can think of no reason why it cannot be a purely physical process.
There are wide and narrow definitions of consciousness. At its narrowest, consciousness is simply our experience of a construct of the world and us in it (working memory, attention and so on are not included). All sorts of processes are going to feed into that experience and all sorts of processes are going to use that experience. But the experience itself is essential to a great deal that goes on in the brain; it has functions, important functions. It is not a frill, spandrel, by-product or a recently emergent human only thingy.
The previous 10 posts in this series outline some possible functions that this construct, and our experience of it, provides. (1) The nature of the construction matches the nature of memory so that the contents of consciousness can be stored in declarative memory (episodic and semantic) and the construct can hold retrieved memories. It can also hold imaginings. This connection to declarative memory gives us our autobiographic narrative, our body of formal knowledge, the material and context we use to imagine and to update old memories. The connection to working memory allows System2 cognition, sequential procedures, use of language/math/logic, the learning of most skills. (2) The prediction of the sensory results of ongoing motor acts is displayed in the conscious construct and can be compared to in-coming sense information in order to monitor and correct movement. It also appears to tags actions according to how they were initiated, giving us a source of learning and a sense of responsibility. (3) The construction provides a sense of location for objects in a three dimensional space, of time, of a theory of mind, of a stable self, and probably other ‘frameworks’ that are ‘hardwired’. (4) The construction provides ways for the brain to communicate with itself. It is a place for attention to be registered which informs the whole brain of what is significant or priority. By the global awareness of the contents of consciousness, the brain can coordinate processes that do not ordinarily work directly together. And with internal speech, complex communication within the brain is possible by attention on words.
Consciousness does not ‘do perception’ but is necessary for many uses of perception. It doesn’t ‘do memory’ but is a necessary input/output for large parts of memory. It doesn’t ‘do cognition’ by facilitates an important style of cognition. It doesn’t ‘do movement’ but is part of the motor monitoring. It doesn’t ‘do learning’ but is necessary for all but the most simple learning. It is just a model. It does do awareness, experience, qualia, feeling. It is the model that we live our whole lives inside.
Here are the links to the entire series: