This article seeks to explain how the fact that we have conscious experiences pretty well proves that it's impossible to explain the entire universe in terms of physics.
Let's get a simple point out of the way first. The word "consciousness" is an abstract noun. I have come across stubborn skeptics who try to shelter behind the grammar of the word itself. When asked how their world-view accommodates consciousness, their reply is "What is consciousness? Can you show me a consciousness? How's your consciousness today? Ha ha ha!" The implication is that these rhetorical questions have no answers and thus the very concept of consciousness is meaningless.
Behind this casual dismissal of the matter lies an important point - one which will ultimately betray those who use such arguments. It is very true that you cannot put consciousness onto the lab bench, but the reason is not that it's an abstract word. In fact, the difficulty of defining "consciousness" objectively is the principle reason why consciousness doesn't fit into science. We should therefore follow the skeptic's comments to their logical conclusion: We should examine firstly whether there actually is such a thing as consciousness and secondly whether it can ever be amenable to objective study. Obviously if it exists but cannot be studied by science then science is doomed to be an incomplete description of the world for ever - and one's philosophy needs to be based on something other than scientific reductionism. That's enough to set the alarm bells ringing for most atheists!
Does consciousness exist? Let's avoid specious arguments based on grammar and re-phrase the question: Is it meaningful to say, "This creature is conscious?" Gilbert Ryle, in The Concept of Mind, tries to tackle consciousness. He comes up with a dozen or more common shades of meaning - such as the ones used in "I was conscious of a noise" or "He lost consciousness". Clearly those don't touch the core of what it's like to be conscious - and neither do his other examples. For a non-conscious being the question "What's it like to be you?" doesn't arise. Consciousness implies experiences. The issue is not what sort of experiences exist but the fact that experiences exist at all.
Of course we may also ask why anything exists. Even if we say "God made it all" it immediately raises the question "Who made God?" Theologians tell us that God is self-existent: the infinite regress of makers is buried within the singular nature of God. However, this only makes sense in the context of the ultimate (or first) cause; it is not a good answer to "Where do cars (or babies) come from?". It can't even be applied to the universe as a whole - as Steven Hawking famously remarked, "What breathes fire into the equations?" We may soon understand the fundamental workings of matter, but why should it exist? Why should anything exist? Here, though, we are concerned with just one thing: consciousness. Can its existence be explained in the same way as the existence of a car or a baby, or do we have to give up and say "It just is"?
To proceed we need to be sure what it is we are dealing with - which brings us back to the skeptic's question "What is consciousness?" Sometimes people try to define "consciousness" as "awareness of self". This is ambiguous since it can mean either knowledge of one's own existence or knowledge of one's own psychological self-hood. "Knowledge of one's own existence" doesn't seem to have any explanatory power: a creature, let's call it a "computer", may very well have a knowledge of its own existence without any experiences at all. "Knowledge of one's own psychological self-hood" sounds more promising but only because it's easy to imagine oneself inspecting one's own mind and seeing that it's conscious. However, it still doesn't explain why the "psychological self" should be conscious in the first place.
Mystics tell us that consciousness does not require a sense of self at all. Whether peddlars in the ineffable can be relied upon in such matters is moot but, a priori, there is a logical possibility of consciousness without self-hood. Perhaps the association of conscious mind with self-hood is so familiar that people assume that where one is there is the other. There are two reasonable ways forward. One is to accept that we all have experiences. The other is to deny that anybody has them, there is no such thing. I have talked with atheists who, I suspect, see the Argument from Consciousness (which I'm not going to define!) coming and accordingly take the position that we do not actually have experiences at all, consciousness is an illusion with some survival value but no reality. It's difficult to persuade someone who has convinced himself that he has no experiences that he has really. How can you describe "what it's like" except to someone who already knows?
Most people by now will have heard of a book called "Consciousness Explained" by Daniel Dennett. Of course the existence of a book with such a promising title is no guarantee that the problem has actually been solved. I can do no better than to quote Wikipedia which says: The matter of consciousness is, of course, under constant and heated debate, and there is no firm agreement on the validity of Dennett's arguments. Critics of Dennett's approach, such as David Chalmers and Thomas Nagel, argue that Dennett's argument misses the point of the inquiry by merely re-defining consciousness as an external property and ignoring the subjective aspect completely. Dennett and his supporters, however, respond that the a forementioned "subjective aspect" as commonly used is non-existent, and that his "re-definition" is the only coherent description of consciousness. This is the essential problem - how should we determine whether the subjective aspect of consciousness actually exists and needs an explanation? However, the debate is usually confused by insistence from one side on only using objective criteria to prove existence; the possibility that we might know that some things exist without being able to demonstrate it objectively is ignored or impatiently dismissed. Because it is true that we cannot prove, say to a particularly clever linguistic computer, that we talking about anything at all.
Naturally, this is eagerly seized upon by skeptics as a weakness in their opponent's philosophy: "Well if you can't even say what you're talking about, how do you expect us to give you a scientific explanation?" But by now the flaw in this logic should be glaringly obvious. Consciousness exists and is familiar enough to all of us that we know what the word means without having a scientific definition. The problem is not for the man-in-the-street who naively believes that his thoughts are conscious, nor for the religious apologist who wants to make the point that science can never provide a complete framework for understanding the world. The problem is for the materialist who thinks that science can (in principle) explain all. This seems an extravagent claim given that no-one has an objective definition by which science can recognise consciousness - whether on the bench or in someone's head. And without a means to recognize it, science is going to have to introduce an ad-hoc law at some point " ... this phenomenon doesn't just look and behave like a living, waking brain, it is actually conscious as well". And no doubt it will be correct in saying so, but merely to assert the fact is not to explain it. In fact such a theory is vulnerable to Occam's Razor. Science explains how the brain works without introducing consciousness: consciousness is a superfluous entity in the picture, it should therefore be omitted.
I am sufficiently confident that consciousness cannot be explained scientifically that I'm making a little offer.
If anyone can explain consciousness scientifically then I will send the first person to do so a crate of champagne, withdraw this article and say exactly why.
By "explain", I mean "explain within the current reductionist paradigm of science". (A philosopher might object that science is not defined as reductionist, but, in practice, it is, even by those who knowingly tell us that materialism in philosophy is defunct.)
You win the champagne if you:
Note that the following are not winning answers for what should be obvious reasons:
My decision is final.
Science does its best to explain complex things in terms of simpler objects put together. Thus psychology boils down to biology which boils down to chemistry and thus to physics. Biology has removed the Life Force from life, everything it now studies can manage perfectly well with just chemistry and physics. A biologist is quite entitled to have a personal opinion that the animal has conscious feelings, but they are represented in the biological model by "states of the nervous system". Biology may therefore be expected to explain consciousness in the sense of describing what conscious beings do. However, in everyday usage it refers to what it's like to have conscious experiences. Thus a proper explanation of consciousness needs to justify equating consciousness-as-understood-by-biology with consciousness-as-experienced-in-everyday-life. Ultimately, the biologist's "explained consciousness" boils down to particles moving about: brain chemicals, electrical forces etc. So the problem is now to reduce everyday-consciousness to particles moving about: observable behaviour, appearence etc. Only then will we be able to say that the two are the same thing. It's what always happens in science. Lightning is now known to be a big electrical spark. We had an everyday description which was physical: the flash and the bang. If lightning had been defined as being an invisible jellyfish living beyond the edges of the universe, it would have been impossible to explain by science. But if popular culture merely believed it to be a jellyfish but meant the flash and the bang when it used the word, science could have proceeded and debunked the folk-myth. In the case of consciousness, there is no obvious way to describe it objectively. Doing so in order to allow science to deal with it is not the biologist's job. It is the job of the philosopher, the person who takes everyday concepts and analyses them. What does a conscious individual look like? What does he do? Until the simple problem of distinguishing a non-conscious being from a conscious one is solved, consciousness can never be said to be explained - by science or any other objective discipline.
For an interesting "near-miss" on this problem, I have a short article on a philosophical concept called the "p-zombie" here.
Perhaps this would be a good point to mention a curious theory due to Roger Penrose, in which quantum effects are credited with being able to create mental effects that Newtonian mechanics cannot. Quantum effects could certainly relieve the brain of having to run on a pre-programmed course: they could provide randomness which might be interpreted as free-will. They might also allow quantum parallel computing so that a relatively small brain can do an immense amount of thinking. None of this, however, explains the qualitative transition from the purely physical to a subjective world of experiences. Some people have taken it a step further, as in this analysis of the Matrix in which the author claims that because quantum effects make the brain unpredictable, they may allow the brain to produce non-physical things like experiences. The logic is cute: you would never predict a brain to be conscious so an unpredictable thing like quantum mechanics is a candidate explanation of how it does it.
Some people are liable to protest at this point that "science might simply stretch a bit so that consciousness gets tacked onto brains". However, this isn't very satisfactory because it implies that the universe is ultimately constructed from four physical forces, quantum mechanics, relativity and an extra "effect" which causes large, highly evolved, living brains to have experiences. One might reasonably wonder what mind was doing for the 11-14 billion years since the Big Bang before sentient animals turned up on planet Earth. We are talking about a major paradigm shift here - not least because reductionism shouldn't have to stretch to accommodate something it can't even talk about objectively.
It should be understood that getting rid of the Life Force from biology also required a major paradigm shift. Sometimes this is cited as evidence that paradigm shifts can occur and science still carries on, rather better for the change. However, this seems unlikely in the case of consciousness. The Life Force was abandoned because there was no discernible difference between something that had "Life" and a merely "living" creature. The Life Force seemed necessary when people couldn't see the mechanics of cells, but it was redundant once they could and it was consigned to the scrap heap. Now that we have consolidated science - it no longer has mysterious Life Forces wafting about - it is obvious that living things are "mechanical", so why introduce a non-physical force? This is the current scientific paradigm, the system that included ghosts in the machine was not properly scientific: there was never any public data to suggest the existence of a Life Force.
The same principle applies to consciousness but with the opposite result. The scientific paradigm does not include subjective entities which have no visible effect on the system. If it did, the way forward would be to remove them just as the biologists got rid of the Life Force. Here, however, we are faced with having to add an invisible "effect" that doesn't actually do anything concrete at all. A paradigm shift to incorporate "soul" or "mind", into science would not be an advance - it would destroy the objective nature of science altogether.
However, we still have consciousness! Unlike the Life-Force, which was invoked as an unseen explanation of things seen, consciousness just plain exists, like it or not. Our everyday thinking readily accepts it and our philosophy must do so too, leaving the scientific method free to investigate objective things objectively. Unfortunately for materialism, philosophers and laymen have been racking their brains for centuries trying to put their fingers on what we really mean when we talk about consciousness. In neural science it's called the "hard" problem, a wry understatement given that the "easy" problem is unravelling the entire workings of the brain.
The only way out will be if the division between private experience and public (objective) observation can be blurred. We can, of course, imagine a "psychescope" that allows us to view other minds, but the problem here is that such a device does not yet exist, so any such invention would have to be verified. The theory of the psychescope must rest on an objective theory of consciousness, so it can hardly be used to verify the very theory it relies on. The psychescope doesn't solve anything. We will be no better off than relying on our individual opinions as to whether a being is conscious or not. Of course we might discover a psychescope without knowing how it works, but then our theory of consciousness would always be incomplete and our primary instrument for detecting it would be a mystery. This just moves the scientific problem away from our brains and into the occult workings of the psychescope. It also raises the question "How do we know it works anyway?" We would be reliant on human beings to say whether a person or animal is conscious in order to see whether the psychescope is responding properly. So our scientific world-view would then be contaminated not only with a mysterious device but also with human pronouncements that cannot be verified.
We therefore need some sort of techno-psychic ability to discern consciousness "directly" so that we can validate the device. If you are wedded to a pantheistic view of reality then this will not seem too implausible. But it's hardly objective science, it's pure mysticism.
It is, of course, arguable that consciousness does affect matter since we can talk about it. Maybe it can affect an instrument too? Maybe an instrument can affect consciousness directly. Maybe two instruments can communicate using a human being's consciousness as the medium without the person's deliberate intervention.
Yes. Maybe. But these speculations extend the known characteristics of consciousness: they do not explain anything. If consciousness turns out to need extensions that allow it to interact with matter then the problem just gets bigger.
The only other hope is that the above argument contains a logical flaw. It would be possible for science to advance to the point where it triggers an insight into philosophy (such as these amateur efforts) so that "post-trigger" it's obvious where there's been a blunder. Other than that, there seems little choice than to accept the fact that mind is an integral part of the universe which does not boil down to physics.
Or to deny one's own consciousness altogether! Hopefully, reality will check in at that point, but I know of atheists who take exactly that view rather than believe in anything that hints at a non-physical reality.