Physics, free-will and individuality., page 1

Absolutely Ridiculous Claims

It may be worth pointing out that what we are discussing here is neither physics nor biology, but philosophy. The subject on the table is causal determinism.

Let's commence with causality. Evidence for it hardly demands scientific citation; causality is all around us. In fact - and this may surprise a layperson who has dined not wisely but too well on the cargo-cult offerings* of 'quantum physics' - events in the macroscopic world always show a classical-relativistic, not quantum, character, and are, as far as we can tell, implacably deterministic. Nevertheless, all events are the outcome of wave function collapses.

This poses a bit of a problem for quantum theorists. The simplest explanation for it lies, as I have argued elsewhere on ATS, in the incompleteness of quantum mechanics, which in its current form is incompatible with general relativity. You don't have to accept my word that it is incomplete; any theoretical physicist of your acquaintance will tell you the same, and you will find the question much discussed, for example in Lee Smolin's highly acclaimed book The Trouble with Physics.

There are, however, other explanations on offer. The most popular one right now is probably decoherence, to which I earlier referred.

What happens to a quantum particle in the real world is that each of its component states gets entangled (separately) with different aspects of its environment. As seen in the page on Quantum Entanglement, when particles become entangled you have to consider them as one single, entangled state (you use the tensor product to calculate the resultant state). So each component of our quantum particle forms separate entangled states. The phases of these states will be altered. This destroys the coherent phase relationships between the components. The components are said to decohere.

You'll find more information on quantum decoherence here. Don't miss the essays.

Of course, decoherence doesn't cut it with everybody. Here's a physicist with a fascinating alternative viewpoint. He identifies himself as a compatibilist, incidentally; compatibilism may be a way out of the straitjacket of scientific determinsm for some, although we may be jumping the gun a little here.

Decoherence is merely a way to explain how the probabilistic world of subatomic particles (or rather, probability functions representing these particles - the only reality particles or anything else actually have in quantum mechanics) collapses into the deterministic world of our experience. But there's more to it than just this: from deep within the theoretical labyrinths of particle physics now comes a suggestion that if humans have free will, then subatomic particles ought to have it too. Meaning - sorry, cargo cultists - not that photons can change course at will, but that human beings can't.

Right: that should just about cover the physics aspect. Let's now turn to biology; in particular, neuroscience.

Twenty years ago, the outcomes of studies by Benjamin Libet [2] began to suggest that the brain detected and responded to stimuli before actually becoming conscious of them. Further work by him and his colleagues tended to confirm this, and further to show that even so-called 'conscious decisions' are in part made and implemented before the decision-making brain is conscious of them.

Now, using brain scans, a group of researchers from the Max Planck-Institut has borne Libet's conclusions out.

Many processes in the brain occur automatically and without involvement of our consciousness. This prevents our mind from being overloaded by simple routine tasks. But when it comes to decisions we tend to assume they are made by our conscious mind. This is questioned by our current findings.

If you're a subscriber to Nature Neuroscience, you can read the paper here.

Studies like these obviously call free will into question. In fact, they cast doubt on the existence and role of consciousness itself, invoking that philosophical equivalent of the Phantom of the Opera, the homunculus in his box at the Cartesian theatre. For some idea of tonight's programme, see here.

These reports from the frontiers of neuroscience also raise strange problems in morality and ethics, as this essay in the Economist points out. Sadly, you'll need to be a subscriber to read it, unless you can find the original print edition; still, this introductory excerpt gives the flavour.

IN THE late 1990s a previously blameless American began collecting child pornography and propositioning children. On the day before he was due to be sentenced to prison for his crimes, he had his brain scanned. He had a tumour. When it had been removed, his paedophilic tendencies went away. When it started growing back, they returned. When the regrowth was removed, they vanished again. Who then was the child abuser?

His case dramatically illustrates the challenge that modern neuroscience is beginning to pose to the idea of free will...

The typical conservative's response to this sort of thing - fear and revulsion - is exemplified by this essay by Tom Wolfe

However, some people aren't quite so fearful or unimaginative. We call ourselves naturalists. We believe that it is possible to live a happy, moral and productive life without the benefit of free will or even the concept of a self.

You can read more about people like us at this site. Though this page is probably a better place to start thinking about naturalism.

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By the way, Buck Division, thanks for putting in a good word for the old Astyan-hack.

*For this useful adjective in the context, I am indebted to the late Richard P. Feynmann, whose Nobel Prize was - as I am sure Syntax123 recalls - awarded for his work in quantum electrodynamics.