Great post on Reductionism over at Emil’s blog.
I wanted to respond to comments there by Peter and Brendan, and give my perspective on their points about solipsism, materialism, science, and how it all fits together for me. Turned out to be a long comment, so I thought I’d better post it here rather than intrude too much and go too far off-topic on Emil’s post. I’ve covered most of this before – links included below.
Peter asks, “How can anyone be sure that what they are experiencing, … In other words, what reason is there for me to refrain from becoming a committed solipsist?”
I’d say nothing is stopping you. I agree with Emil’s take on solipsism and other rationalist philosophies. But my personal perspective is that it boils down to a rational choice. Considering just solipsism v materialism, to some extent the choice is arbitrary. You could ask what the consequences would be in each case, comparing what is the case with what you think is the case:
1) Solipsism holds, and I choose to believe in solipsism. I’m not sure what I learn from this. It seems that I imagine the world, including you and this conversation. I acknowledge that it might be you that’s imagining me as part of your solipsistic experience, so that I’m a figment of your imagination. What I feel is me thinking is actually you thinking the thoughts in some subset of your solipsist consciousness. How do we tell which is which? Do we have any control over this? Instead of being a mind that imagines being a material life form on an imagined material earth, can I choose to switch arbitrarily to become a life form on the surface of the sun? I seem to be limited to imagine only the earthly being I appear to be. What if I walk in front of a bus. It’s only imagined, so will I simply continue as if I hadn’t? Our (mine or yours) solipsist experience seems to be limited by what seems like a material reality.
2) Solipsism holds, and I choose to believe in materialism. I can’t distinguish what actually happens here from (1), except perhaps I suffer less anguish over whether I am a constrained mind. Though I am a solipsist mind, I go along with the material illusion. Consequences?
3) Materialism holds, I believe in solipsism. Again, I’m not sure what the outcome might be. I could conceivably die trying to test my solipsist existence by attempting to defy gravity; or maybe I pick a fight in a dark alley somewhere. I’m not sure how I’d distinguish my mental experience here from being absorbed in a gaming system as some avatar. The physical reality might soon make itself known to my mental experience.
4) Materialism holds, I believe in materialism. No problem. Business as usual trying to figure out how all this works.
In the grand scheme of things it doesn’t really matter if you choose solipsism. You have to do an awful lot of work to get anywhere it seems with solipsism other rationalisms, idealism, transcendence or theism. Lots of inner contemplation, meditation and maybe praying. But it seems you still need to eat. It is sometimes claimed by theists that there are no atheists in foxholes. This is clearly untrue. I’m much more convinced that there are no solipsists at lunch time.
I don’t know any committed solipsists. If I did it might be worth a charge of assault to punch one on the nose. Dr Johnson’s “I refute it thus”, while not an actual logical refutation, I do find his kicking a rock is still pretty convincing. Peter, if you’re visiting this post, do you actually know any committed solipsists yourself? Are you personally persuaded? Your answers might in part answer your own original question.
My route from Cartesian doubt to empiricism, avoiding solipsism, is here and here. The material world is so persistently in-your-face. It seems more productive to try to understand it rather than persist too much with deep scepticism about it. If it turns out that I’m wrong and that I am a solipsist mind then I just hope it comes out in the wash. In the meantime I’ll enjoy that lunch.
Once you choose to accept materialism a lot of consequences follow.
Science (evolution, biology, etc.) tells us we are physical systems no different from the rest of the material world. We are just made up of stuff in some complex way, as Emil describes well as reductionism. From evolution and biology we learn we evolved from animals with much less capable brains, and even from animals with no brain at all.
Our ancestors were very clearly interacting with the rest of the world, of which they were simply components. This interaction was physical, chemical, electromagnetic: when microbes touch there is a greater or lesser degree of chemical interaction as their outer cells come into contact, with electromagnetic interaction of the individual atoms and molecules (the machinary of chemistry). This in turn caused physical and chemical reactions within the bodies, to greater or lesser extent: the touching body is an obstacle, food, or predator.
Neurons and simple nervous systems that don’t fit our loose definition of consciousness are owned by animals that interact with the environment with a greater degree of autonomous control. Memory becomes possible. See Kandel on Aplesia and other sources. More complex brains do more complex stuff, have more complex memories, can predict more about the environment, even if not consciously: a cheetah tracking prey that is trying to evade it.
Sadly we don’t have access to our ancestors in the process of becoming conscious as we are. But it’s not too much of a stretch to infer the following.
The lighting up of human consciousness may have been quick or slow, in terms of evolution, and in terms of generations – we don’t have the details. The species distinction doesn’t really matter here: in the trail back through our ancestors there is no point, we think, where a daughter is not of the same species as the mother; and yet, if these various ancestors could be brought together, they would be classed as one or more species different from us and each other.
As an analogy for the onset of human consciousness and self-awareness take an infant. It’s not clear that a new born has much of a conscious cognitive life. It can certainly respond with basic consciousness, as much as some animals can, but less than some adult animals. Do you remember your early infancy, your birth? Conscious self-awareness seems to creep up on us; and more advanced cognition comes from the physical experiencing development of the brain: learning. It’s hard to look back as an individual, and as a species, to see and acknowledge how conscious self-awareness emerged. There is a gap, and we have had the tendency to fill it with a soul of one sort or another. I feel this gap contributes to our special respect for our conscious mind, and our deification of it – at least to the extent that we think it a spark provided by a deity.
Then there is the physical sensibility of the brain, or lack of it. Though the brain can sense the outside world and something of the inner body, through sight, hearing, touch and the other senses, the brain can’t actually feel itself in the same way. There is no sense in which the brain ‘feels’ its neurons working away, as it can feel an arm moving or touching something. Introspection seems to stop at the mushy level of concepts, thoughts, internal images and sounds – but it can’t locate them. Do you feel neurons flashing in Broca’s area and Wernicke’s as you form and interpret speech? Can you feel in your brain where the concept, the thought, the conjured image of your grandmother is located? No, but neuroscientists can detect at least some of the neurons that are associated with that sort of perception (a summary article, a particular article, recent paper from Quiroga himself).
Our working brain, our conscious selves that are self-aware are only remotely self-aware. Our introspective brains build a vague concept of self the way they build vague concepts of anything else. Our brains even build a concept of mind. And it’s a detached mind, it appears, because of these limitations on our introspective capabilities. This is the nature of the illusion of consciousness. Yes we have consciousness, we experience it. The illusion is that the conscious self is a mind detached from the physical brain: dualism.
Emil said, “Dualism may represent the majority of the population, but certainly not the majority among scientists or philosophers.” I would be more inclined to say the among scientists or philosophers most are non-dualists, intellectually, but, as with visual illusions, none of us can overcome the mental illusion as we go about our daily lives – we feel like free-thinking minds somehow embodied yet not quite part of the furniture. We feel like dualists.
On top of this there is a massive cultural history from philosophy and theology that has constructed quite a different story; one in which the mind does exist as a separate special non-material entity, a soul in some stories. These are excusable stories from an excusably ignorant past. The excuse is wearing thin.
This ancient perspective, which still exists, mainly with theologians, but also with philosophers, particularly those that don’t follow neuroscience, biology generally, or evolution, is what I refer to as the problem of The Primacy of Thought – where they feel that our primary source of knowledge is our conscious mind. I agree that we perceive the world through our minds, but the evolutionary evidence is that we are primarily experiential animals with a brain upgrade that enables us to reason (an interesting process in itself). We and our world are physical, and even though our mental experience of that world goes on in the mind, that mind itself is actually the busy active dynamic brain.
We can infer all this empirically from what we know from science. We can’t prove it logically to the satisfaction of pernickety philosophers, but it’s a more fitting explanation that any fanciful philosophical ideas. All the evidence is not in yet. The hard problem of consciousness remains in the mind (brains) of many philosophers, and particularly theologians who desperately want there to be a soul. It’s not a complete story by any means.
It’s even a bit of a just-so story, though one that is consistent with all existing evidence. I’m sure philosophers that don’t like it would be quick to point that out. But it’s a damned site better than any other on offer, better than any theology or any of the non-materialist philosophies.
And of course, being an empirical perspective on materialism it not only all holds together, it is also open to adaptation in the face of new evidence. Even while waiting for more concrete evidence of physicalist accounts of consciousness all we would need to drop the idea would be some counter evidence. I don’t see any. Not a bit.
Personally I think the evidence is overwhelming already. As Emil puts it, “If you pay attention to the history of neuroscience, you would understand why physicalism has conclusively won the argument … “. Really, start looking at the evidence. Look at all the examples of how changes to the brain, drug induced or physical, including intercranial (open skull) probe sensing, and stimulation, show a direct cause and effect relationship between the physical brain and conscious experience.