Is free will an illusion?
Maxine Clarke
Wednesday, 03 June 2009 10:04 UTC
Scientists and philosophers are using new discoveries in neuroscience to question the idea of free will. They are misguided, says Martin Heisenberg, professor emeritus in the department of biology at the University of Würzburg, in a Nature Essay (Nature 459, 164-165; 14 May 2009). “At the scale of planets, quantum effects give way to the deterministic laws of classical mechanics. At an intermediate scale, however, they are occasionally amplified to become observable, for example when we measure radioactive decay. In general, life is an interplay between the deterministic and the random. There is plenty of evidence of chance at work in the brain: take the random opening and closing of ion channels in the neuronal membrane, or the miniature potentials of randomly discharging synaptic vesicles. Behaviour that is triggered by random events in the brain can be said to be truly ‘active’ — in other words, it has the quality of a beginning.”
There is plenty of evidence, Professor Heisenberg writes, that an animal’s behaviour cannot be reduced to responses. Fruit flies, for example, can modify their expectations about the consequences of their actions when in situations they have never encountered. They can solve problems that no individual fly in the evolutionary history of the species has solved before. They can be made to use several different motor outputs to escape a life-threatening danger or to visually stabilize their orientation in space. Thus, according to Professor Heisenberg, self-initiated action is not in conflict with physics and can be demonstrated in animals. Humans can be considered free in their behaviour, in as much as their behaviour is self-initiated and adaptive. We need not be conscious of our decision-making to be free. What matters is that our actions are self-generated. Conscious awareness may help improve our behaviour, but it does not necessarily do so and is not essential. Why should an action become free from one moment to the next simply because we reflect upon it?
Updated 03 June 2009 10:13 UTC
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Martin Heisenberg (Nature 459, 164-165) makes a number of intriguing points concerning the reality (or illusion) of free will in humans and other animals. However, to my mind (free or otherwise), his review overplays randomness as a route out of slavish determinism. Stochastic noise, quantum mechanical or otherwise, hardly seems the path to a triumphant restoration of self-determination. Instead, while it counts more as a hint or indication rather than hard empirical evidence of an underlying mechanism, the appearance of free will is telling from an evolutionary perspective. Assuming that free will is annulled (and I include Heisenberg’s stochasticism in this class), a biologist might well question why natural selection has gone to the bother of giving organisms the perception that they are ploughing their own furrow. If there is no possibility of any consequences of this perception feeding back to guide events, why has selection acted at all? Furthermore, why has selection furnished the minds of animals like ourselves with all sorts of carrots (pleasure and love) and sticks (fear and pain) to guide us towards goals that service the genes that build us? Heisenberg is right to question overeager neurodeterminists, but he may have chosen (or not, of course) the wrong route for doing so. One question for those who deny a seemingly obvious feature of personal reality is why, given that we are only scratching the surface of neurobiology, that we have yet to determine which flavour of quantum reality is the right one, and that the universe contains no shortage of as-yet inexplicable phenomena, why we can so quickly preclude free will.
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In his essay ‘Is free will an illusion?’ (Nature 459, 164-165; 2009) Martin Heisenberg discusses the relationship between free will and random action. He observes that some theorists discussing recent neuroscience studies might have underestimated the role of random neural dynamic in free behaviour. However, some questions related to social influence rise from his arguments.
He points out that freedom is reached because we are able to follow moral laws. Nevertheless, some people could argue that society, and moral laws in particular, could be constraining our free action. Due to the fact that we have been brought up in a particular culture which is characterized by a set of specific moral rules, we are implicitly restricted to act according these behaviour patterns. It is true that everyone is not influenced by society in the same way or degree because the influence depends on the importance someone attributes to subjective norms but, social pressure is, in many cases, a strong predictor of behaviour. So neither the stimulus-response model nor the moral model can inform about free behaviour.
On the other hand, the stunning idea of random action introduced by Heisenberg is really promising. Future advances in complex mathematical models may be able to solve the question of self generated responses with in the next few years. The principle of randomly generated behaviour could also be the starting point for a better understanding of, among others things, creativity and emotions.
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Is free will an illusion? A response to Martin Heisenberg
Recent observations using functional magnetic resonance imaging suggest that our actions may be predetermined in the brain up to 10 seconds before we become aware of them (CS Soon et al.: Unconscious determinants of free decisions in the human brain. Nature Neuroscience, 11:543-545, 2008). In response, Martin Heisenberg argues in his recent Essay, that observations from quantum physics and from animal behaviour make a strong argument for a free will and against a deterministic view (M Heisenberg: Is free will an illusion? Nature 459, p 164-165, 2009). Both sides make a strong argument, so which answer to the question about free will as opposed to determinism is correct?
If a question is still under debate after more than 3000 years of intense dispute, one may speculate that the question itself is wrong.
The real issue behind the discussion of free will is that of responsibility. However, if there is no free will, there may be no responsibility. Therefore, the debate has focused on free will. Freedom in this context is viewed as contrary to determinism. This view is misleading. The contrary of determinism is chance. In the light of responsiblity, chance is even worse than determinism. It is the “horror vacui”. How can we call anyone responsible for an act which is the result of chance? A positive definition of free will is that freedom is a measure for the capability to make decisions. As a first step, if it is principally possible for me to turn to the left or the right, I have more freedom than if I can only turn to the right. There are physical, biochemical, physiological, psychological and sociological aspects that may contribute to my decision. The more aspects I am able to consider for my decision, the more freedom I have. Eventually, I will do the one or the other and this action is always determined. Even if there are random events ahead, like the opening of ion channels in my brain, these events finally contribute to a determined action. In this light, a free will and determinism are no longer contradictions. It is not a “black or white” distinction, but freedom is of variable degree, depending on the amount of possibilities that I have to make up my decision. As another important consequence, we must realise that freedom is largely variable in our society. It is not only a question of democracy or dictatorship. It is as well a question of age, wealth, education, exercise, intelligence and health, which determine our degree of freedom. -
What is lacking here, as usual, is a precise definition of free will. Often people supporting different opinions regarding the existence free will are also thinking about different definitions of the term.
So far each time I see a definition of ‘free will’ it has one of the following undesirable properties:
- It is obvious for everybody that that kind free will does exist (for instance Heisenberg’s).
- It is obvious for everybody that that kind free will does not exist.
- It is obviously impossible to pursue the idea by means of scientific experimentation (for instance when soul is involved).
- It is too vague, as to decide which of the previous properties applies, if any (for instance when it relies in another under-defined term like consciousness).
And very frequently, the definition is implicit at most.
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I have just read the two comments to this article. I’ve contacted Dr. Vermeersch about his comment. Here’s an excerpt of what I wrote:
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I have just read your commentary in Nature on the article of my PhD supervisor Martin Heisenberg on free will. Our group has recently found evidence for a plausible biological mechanism behind free will, which is close to what Martin Heisenberg was alluding to in his essay.
Reading your commentary, it occurred to me that it is possible you might not realize that in order for free will to make any sense, ‘free’ has to be separated from ‘will’. It is this separation that we believe we have found evidence for. Independent of us, the other commenter in the same issue of Nature, Bob Doyle, has developed similar lines of thought. He has also written a very nice summary of why the standard critique of free will fails . I think it addresses many of your thoughts expressed in the comment.
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I have just recently learned of Bob’s interest in the matter and discussed some of these aspects with him over the phone last night. He has some more great information on the topic, such as a history of the debate and his own solution, the cogito model, which also comes very close to our interpretation of our data. However, for fruit flies, Bob would prefer prefer to call it the “‘biophysical basis for behavioral freedom’, which is conserved by evolution and shows up as a prerequisite for free will in humans.” Which is perfectly fine with me. -
Posted on behalf of Bjorn Brembs:
I have had a look at who Dr Vermeersch actually is and was quite surprised to find a very a distinguished academic with an impeccable track record and outstanding reputation in philosophy. I must have misunderstood something completely in his Correspondence. First, Dr. Vermeersch seems to repeat an old argument: “deciding freely does not imply lack of determinism”. I’m sure Dr.
Vermeersch is aware that determinism has been dead since the Heisenberg uncertainty principle and so needs no rescue. Why would Dr. Vermeersch seem to give the impression to want to rescue it anyway? What did I misunderstand?
Furthermore, towards the end of the comment, he states something that appears to almost amount to a triviality:
emotions play a role in our decisions. Of course, if there’s a lion charging at me I may chose freely not to run away, but which person will really do that in this situation? A man with Dr. Vermeers profession and specialty surely knows better than me that physics, chemistry and biology constrain our freedom. Otherwise we’d all be flying around like birds.
This means there’s something I misunderstand completely.
Maybe it’s just me, but maybe there is something to clarify for others as well, since the other commenter, Bob Doyle, made perfect sense to me.
So what could Dr. Vermeersch possibly have been trying to say?
Bjorn Brembs -
Free Will is not an illusion. By the way, I am only saying this because my wife told me to.
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My own take on this is the following. We can think of systems as being ‘weakly determined’ and a ‘strongly determined’. Strongly determined systems are Laplacian, in that everything about them is known, from the rules that govern their parts to the exact state of those parts. Strongly determined systems must be known at their most fundamental possible level. Weakly determined systems are known in terms of the phenomenological relationships, accepted as laws if they meet certain criteria, and the more or less exact state space of that system.
Aside from the infinite precision that non-linearity demands and Heisenberg forbids, strongly determined systems have other conceptual problems. One of these is the nature of the “laws that govern them”, a glib phrase that implies fundamental knowledge, However, an issue for physics when it considers a theory of everything, from what are these fundamental laws constructed? If they describe the deepest things that can be, then are they too made from these deepest things? Thus, recursion into mathematics with the vague hope that it will all boil down to groups, primes or something else of which Kant would not approve.
Weakly determined systems obey phenomenological laws: we do not say why this or that works, merely we note that it does. One gas molecule cannot display heat or temperature, many do so. The laws emerge from the statistical properties of the system – another arm wave – much as prices emerge from a market. That is – and this is a non-trivial observation – regularities exist in only retrospect, when they have been negotiated into existence by huge numbers of agents, be they buyers and sellers in a market, organisms in an ecology or renormalised particles in a lump of material. If these transactions do not occur, then the regularities – prices, pressures – are not realised but latent in the dynamic of events; what I think Heidegger meant by Dasein – the dynamics of being – and Seinkönnen, potential for being. Regularities such as gas laws are not, therefore, intrinsic things that stand outside of the business of being, but the consequences of endless interactions and negotiations which, because they are conducted by simple and universally identical entities, always give the same outcome. Thus, we see a law, but it is a law cooked up by the things to which it applies. This is not an artifact of our description, but how reality assembles itself.
Let us introduce the related, if blurred, concept of emergence. At its most basic, it represents the common observation that simple things, when connected together, give rise to more complex properties: much what we have seen for phenomenological laws, as expressed in the paragraph above. One can see this best in our descriptions of things, so I will use an example which could be criticised as being only about our way of seeing events. However, some thought will show that this is not the case.
Consider a perfectly described ant: we have it modelled, and we have the model in perfect homology with the physical ant in its physical environment, poised and ready to run. Being a model, it is perfectly determined. Being a perfect model, it sees what the ant sees, and does what the ant does. the two run in parallel, with the model perhaps a tick ahead of the physical ant. The ant has never seen another ant before,and so neither has the model. Our ant, however, encounters another; and between them they quickly cook up ‘any social behaviour’. The same thing happens in the model: ever assuming that ant social behaviour is emergent in silicio as well as on silica, the model is changed, made more complex, explores a broader state space than that for which it was designed. It has a new bunch of rules that were not there before. These are regular in retrospect, but did not exist in prospect, save as what Martin Heidegger called Seinkönnen. That is, the system is weakly determined only after the event. Before the event, it was also weakly determined but by a lesser state space: at the event, it made a transition which could not be determined because the rules to determine it had not yet been constructed.
Evolution has precisely this form: before something evolved to emit certain properties, those properties were not emitted. The regularities associated with the new degrees of freedom that they introduce into the system are, therefore, new rules. Apply, please, the same thoughts to information processing or cognitive structures. Prior to learning, they are bound by one set of rules, after learning, by another. However, the new rules are not predictable from the old, as they transcend their state space.
Is this refutable in terms of strongly determined systems? As already noted, there are deeply dodgy assumptions built into the idea of a strongly determined system that make such a preparation essentially impossible to generate. Science pins degrees of freedom, but it cannot totally know a system. However, as a thought experiment built on a quaking bog of impracticality, does strong determinism refute emergence? I think not. Electrons are being pushed around in the processor of the machine on which I am typing this. The immediate reasons are duly scrutable – finger, button, IT magic, charges – but have to be cast in a wider and wider set of ‘whys’ to encompass a total explanation of the electron’s experience. Why was that machine delivered to my door? Why did my cognitive history and architecture lead me to respond, but also why did it rain on Sunday and make me stay indoors and read the article to which I am responding; and..? Robbed of grand generalities, strong determinism fades into a blur of contributory factors that have to evoke the entire light cone of the planet and everything impinging on it. I type this because of how certain particles collapsed out of the false vacuum of the Big Bang? Oh please, pass the parsimony.
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Re. my last, para 5: that should be “ant” social behaviour, not “any” social behaviour. Apologies.
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This is a comment to Oliver Sparrow message.
Brilliant!!!!
I almost completely agree with Oliver Sparrow’s arguments. I think the differentiation among strong and weak determined systems is essential. I also agree with the idea that scientific laws are statistical generalizations. But the most interesting argument, from my point of view, is considering complex behaviours as a result of “simple things”.
Nevertheless, the main drawback here is to apply this theoretical background. I mean, how can we describe natural phenomena by using complex mathematics? More precisely, how can we explain both short-term and long-term memory using the complexity approach? Or, how can we use the concept of “emergence” to describe the learning of a language?
Yes, I know the theoretical explanation posted by Oliver Sparrow is valid to explain all phenomena but what about to precise models designed to predict and control events? For example, what about a concrete model to prevent memory degradation in Alzheimer’s disease? Or, what about a set of rules to improve language learning in children with development problems?
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