Little to say for myself
Wednesday, June 04, 2003
Free what?Last summer (and the summer before) I was in an experimental production of Macbeth, playing a character who was intermittently possessed by the spirit of Macbeth himself. During the periods when he was not actually possessed, my character expounded his theory (to anyone in the promenading audience who would stay to listen) that Free Will is a Myth. Each of the seven cast members (the illustrious Mr. Happy amongst them) explored a different aspect of the play, and my character's was Free Will. During the long rehearsal period and throughout the performances I developed and extended his argument to such a degree that lots of people felt compelled to tackle me on it after the show. Most of them (including members of the cast and the directors) told me what crap it was, and how frustrating it had been to listen to without being able to challenge it. A few others (in particular a group of American students, bless them) thought it was really good. What struck me most was that so many people had an opinion.
Since that time, probably because I put so much work into honing the theory, I haven't been able to shake off the feeling that, in its own way, it's right. That and the fact that one of the audience members, who was a Cambridge post-grad philosophy student no less, asked where I had got the material from - because it represented the view that current thinking was heading towards. I don't think he was taking the piss.
Anyway, the argument went something like this:
At the physical level, i.e. according to physicists, the behaviour of the whole universe can be explained in terms of three fundamental fields of force: the strong nuclear force, electromagnetic force and gravitational force. Everything, from the goings-on inside the nucleus of an atom to the making and breaking of galaxies - with the workings of the human body and the planets on a scale somewhere in between - is governed by those three forces and nothing else. They are sufficient to describe the behaviour of all matter, and all the space in between the bits of matter. For the last handful of decades, scientists and mathematicians (Einstein amongst them) have tried to come up with a Unified Field Theory that links these three together, but hitherto they've failed. Thus far, these three forces represent the most basic building blocks for our universe.
At the human level, according to pretty much everyone, when we experience and talk about the things that represent our individual Free Will (our thoughts, ideas and choices), we generally accept them as originating in our heads - or at least within us somewhere. We mostly agree that it is our brain that is the mechanism for these thoughts. Although my argument could be applied generally - it is easier to work with the assumption that it is the brain at the centre of things.
At this point, some people want to jump in and say "Aha - you're a determinist. You're implying that the whole universe (including the human race) is simply a complex mechanism that, had we the tools, we could follow through to predict the entire course of events to the end of time. That's ridiculous."
Agreed. That is ridiculous, and it's not what I'm about to assert. Apart from anything else, the well-known Heisenberg Uncertainty Principle states that we cannot know physical phenomena accurately enough to predict their exact consequences - not because our analytical or measuring tools aren't accurate enough, but because that is the nature of nature itself. Once a chain of events gets to any sort of length, or has a large number of variables, the uncertainties multiply to an extent that makes prediction impossible. Hence the vagueness of weather forecasting. So I'm not arguing that everything is predetermined. I'm arguing that matter cannot, of its own accord, change the way that it responds to the physical forces that influence it. If you imagine a falling raindrop, it is impossible to determine, from the moment it leaves a rain cloud, exactly which point on the ground it will hit, but at the same time it's perfectly reasonable to accept that where it does land is not decided by the raindrop itself. But I'm getting ahead of myself.
So, to get back to the point...
It can easily be shown that the human brain responds to the three fundamental forces of nature in much the same way as any other piece of matter. I'm afraid I can't think of a simple way to demonstrate this for the strong nuclear force (SNF), so I'll address this first. The SNF, as the name implies, describes the way that the nucleus of an atom holds itself together. It is the force that gives the hundred-odd elements (hydrogen, oxygen, sodium, iron, gold etc) their identity, and stops them from changing into other elements. It is a very, very localised force. Its influence doesn't even stretch out as far as the electrons in the same atom, never mind beyond the atom itself. As such, it doesn't play a part in how the atoms combine to form molecules, which is the basis of chemistry. That's the job of the electromagnetic force. You'll have to take it from me that the SNF forms no part of the workings of the brain, other than the fundamental job of holding its atomic nuclei together and stopping the atoms transforming from one element to another. I suppose it can be argued that the nuclei of the sodium ions in the nerve fibres of the brain obey the SNF because they don't spontaneously change into potassium ions, or helium atoms, or lead atoms, or anything else, but I can't demonstrate that here. You'll just have to take that bit on trust. There is certainly no scientific or philosophical debate over any part played by the SNF in the human brain - in that the atoms of the brain obey it to the same full extent that atoms anywhere else in the universe obey it.
From now on it gets easier. Let's look at the other fundamental forces.
If you throw a brain out of the window, the Earth's gravity acts upon it and accelerates it towards the ground. Given the usual parameters of height off the ground, air pressure, initial trajectory etc., it is entirely possible to calculate with some accuracy the point and time of impact with the ground - just like for any other lump of material of similar size and weight. More prosaically, if you put a brain on a weighing scale, it registers a weight. This weight is caused by attraction to the Earth. The brain is therefore subject to gravitational forces.
If you put a brain into a microwave oven, it will heat up - due to the effect of the electromagnetic field (the microwaves) on the molecules in the brain. Knowing the weight of the brain (from the previous experiment) and the power rating of the oven, it is easy to calculate the rate of cooking - just like for any other similar lump of flesh. The brain is therefore subject to electromagnetic fields.
Thus, if the brain is subjected to any of the fundamental forces of nature - it obeys them:
Thought processes result from chemical changes taking place in the brain. Electrical impulses move along nerve fibres, thanks to movements in local sodium and potassium ions. The same sort of chemical processes that lead to thoughts also provide the signals that travel into the brain via sensors (like the eyes and ears), and out of the brain to control the muscles of our bodies. This is all well understood to be the result of electromagnetic forces at work.
Now, the concept of Free Will implies an ability to generate independent thought - as distinct from the robotic situation where every event comes about inevitably as a result of a previous stimulus. For Free Will to happen, something in the brain itself would have to initiate the chemical reactions that occur within it, and dictate the pathways they take through it. But, as we've already seen above, every single atom in the brain behaves itself consistently when it comes to the three fundamental physical forces. Thus a chemical reaction (i.e. a thought) could only take place if the combination of fundamental force fields in those brain cells allowed it to do so. In other words, there still needs to be the right chemistry going on immediately before it. If you keep tracing the chemical steps back through the process to their previous steps, eventually your path will lead back to an event outside the brain itself.
This means that, for Free Will to exist, there must be something additional happening in the brain which doesn't obey the three fundamental forces. In fact we could even define this thing as being Free Will itself, since this is the bit that distinguishes the independent thought from a robotic response. Let's look at that:
Either Free Will (this thing that disobeys the three forces) has always been out there in the universe, or it appeared somewhere along the way.
Well, the brain is a complex thing. We know from simple examples like optical illusions that it is possible for reality to be one way, but for our brain to perceive it another way. Another example is phantom limb pain. Just because we perceive something to be there, doesn't mean it actually is. The reason we humans are such a successful species is because we work together. As individuals we're not strong, not very fast runners or climbers, not good swimmers, can't fly. But when we get together, we can overcome these weaknesses - and we have. The reason we've been able to work together is because we all have an agreed code to live by. A way of distinguishing between helpful and unhelpful behaviour, so that helpful behaviour can be encouraged and unhelpful behaviour discouraged or eradicated. In other words we have a set of morals. The existence of morals presupposes the concept of choice. If you can't choose to do the right thing or the wrong thing, morals would be redundant.
Unfortunately there are some philosophers who use this very point as sufficient "proof" of Free Will. They argue that, because the concept of morals exists, and because such a concept only makes sense in the context of the existence of Free Will, there must be Free Will. To me, that argument's a prime example of begging the question. It presupposes the existence of morals and then uses their existence as proof of the existence of Free Will.
It's possible to describe the concept of time travel, but that doesn't mean it therefore has to be physically possible to do.
To me, it's important to apply the principle "If it looks like a duck, and quacks like a duck, it's probably a duck." You go for the most likely explanation until such time as it's disproved. If Free Will did exist, it would require something highly improbable. Something that operates alongside (but separate from) the three fundamental forces of nature. This something would operate only in the tissues contained in the skulls of a particular species of animal on the surface of this particular planet. It either always existed in the universe, but lay dormant waiting patiently for the right sort of species to evolve to harness it (in which case there would have to have been some mechanism for harnessing it), or it spontaneously arose out of the ether as a result of the evolution of that species (in which case something will have been given rise to which, by its very nature, is not possible to give rise to).
The alternative to this highly improbable course of events is that Free Will is just one of the many illusions that we know the brain to be susceptible to. It's been a very successful illusion - allowing our dominance of the planet despite our physical shortcomings - but an illusion nevertheless. There are a couple of examples that occur to me of cracks in the illusion, where we can glimpse the true nature of the brain's operation:
There are a couple of problems with this theory:
posted by Plig | 05:20 |
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