On the Possibility of Libertarian Free Will

This is a brief attempt to show that while remaining unlikely, the existence of Libertarian Free Will is not an impossibility within the bounds of our current scientific and philosophical understanding.

My aim is to identify both the possibilities and any problems with them that need tackling.



First we need to acknowledge that there are effectively two causal systems in play in the world:

1) the deterministic system of our macro-scale, aggregated, classical physics. Let us call this the D-system.

2) the indeterministic system of micro-scale quantum physics. Let us call this the I-system.

It is uncontroversial that there are brain processes that operate in the D-system, unfolding deterministically. Let us call these D-processes. It may also turn out to be the case that there are brain processes that operate in the I-system, unfolding indeterministically¹. Let us assume this to be the case and call these I-processes.

For our purposes we need to imagine a D-process D  that assesses a range of possibilities from which the agent is to choose. It doesn’t matter if D is a conscious process or not. What matters is that left alone, will evolve deterministically.

However, in this case D initiates an I-process I that consists in the agent’s imagining of the future, to aid in its decision. We might characterize this event as D requesting data from I, and I returning data to D.

Since the I-system is indeterministic, the data returned will be random. It will however be constrained within the context of the data request (so for example, a request for data on choosing between cheese or chocolate is more likely to return imaginings of taste or waistlines than it is of drowning or London buses).

Data returned from I may or may not be novel with respect to previously existing data available to D. If the data is novel, then depending on its practical feasibility, it may provide additional possibilities from which D can select. Therefore the unfolding of D without the novel data from I may differ from the actual unfolding D with the novel data from I.

From this, we can see that one component of Libertarian Free Will is possible, consisting in the ability of an I-Process to return data to a D-Process, freeing the D-Process from the determinism of the D-System by way of a swerve from the deterministic system to the indeterministic system. However, this implies a random swerving, which is not good enough for Libertarian Free Will. So we will continue.



It is reasonable to suggest that the more data that is returned from I, the more likely it is that D will go on to select a possibility that only became available due to that additional data.

It may also turn out to be the case that the I-system operates in a non-temporal environment². Let us assume this is the case.

Given this assumption, the amount of data returned from I cannot depend on a variable set by D that results in a determined amount of time for I to complete the task. We say this because the amount of time used by the I-process – being that it is a-temporal – is always zero. The I-process takes place outside of both a spatial and a temporal structure.

If not determined by a variable set by D then perhaps it is reasonable to think that the amount of data returned from I is determined by something intrinsic to the I-process itself. It could be this variability in the I-process that corresponds to the conscious effort of the will, providing the non-random element of the swerve.



So if an agent exercising free will does so within the I-system, this not only implies that a function of the agent – its imagination – resides in that system, but that at least a part of that which defines its character as an agent – its strength of will – does so too. The question then becomes that of how a semi-persistent character trait can retain its integrity in an indeterministic environment.

I’ll return to this in a future post.



¹ c.f. quantum biology
² c.f. quantum gravity and emergent spacetime


A defense of non-epiphenomenal consciousness and free will.

[NOTE – this is re-post from the original incarnation of this blog.]

The existence of non-epiphenomenal consciousness and free will are two different, but related issues. Both are disputed by those of a physicalist persuasion, and both find themselves lacking any place within our current scientific understanding of the world. Indeed, they not only have no place, but also run contrary to a key precept of modern science: that there is no such thing as an uncaused cause.

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In the classical Newtonian picture of physics, the processes that lead to a particular brain state are governed by deterministic laws of nature. If in principle we could perfectly describe a starting brain state, then by extrapolation using those laws, we can predict with certainty a subsequent brain state. Quantum mechanics overthrows this view, revealing that fundamentally, all processes are probabilistic in nature. Instead of predicting with certainty, instead  we only have a probability that one result will win out over another (even if in macroscopic systems there are so many quantum elements that the law of averages means the probability is very high indeed). This introduces a random element to the possible evolution of systems over time, but doesn’t necessarily help with defending free will. A random result is not necessarily a free one.

This fundamentally random, but practicably deterministic state of affairs is what we observe in every area of nature we’ve ever cared to study. Physical processes alone are sufficient to explain the evolution of systems in time. So what role could mental processes have if they exist at all? And even if there is a role, by what conceivable mechanism could a mental process affect a physical process?  This is the problem of defending non-epiphenomenal consciousness.


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Beyond questions of the efficacy of conscious systems looms the even more unlikely notion of traditional incompatibilist free will; a concept seemingly so contrary to what we know about nature that most philosophers and scientists appear to have abandoned it altogether. And it’s not difficult to see why. The suggestion appears to be that not only does the mind play a role in the evolution of brain states, but that it can also derail the chain of cause and effect by somehow tipping the probabilities in favour of what would otherwise be a vanishingly unlikely alternative options.

Given those facts, how can defenders of causally efficacious mind and free will construct a believable argument for their existence?

To be taken seriously, both non-epiphenomenal consciousness and free will are desperately in need of a viable mechanism. Without it, both are rightly open to attack as being only explainable by supernatural forces. And to be viable, I would argue that any proposed mechanism would have to both conform to our current best-fit scientific theories and be robust enough to be considered mainstream.

Some may claim that such questions are outside the scope of science altogether, being that evidence for their existence is purely subjective and therefore unverifiable by the scientific method. With most such phenomena I would agree. For instance, believers in gods may try to claim that their experience of the divine counts as evidence, while others use subjective experience to underpin all sorts of dubious pseudoscience and quackery. So right away, I should make it clear that  I consider non-epiphenomenal consciousness and free will worthy of explanation for one reason alone: they are – at first blush at least – subjectively universal phenomena. Even the most ardent physicalist must admit that without further reflection, we appear to have both. That of course is not proof – appearance often misrepresents reality – but it is I think, at least reason to investigate as best we can with an open mind.

An axiom attributed to ancient Greek philosopher Parmenides and later made famous in the modern Western world by William Shakespeare in King Lear says that “nothing comes from nothing“. The antithesis of this idea is the idea of creation ex nihilo, or “out of nothing”. The gods of many religious traditions are supposed to have pulled off such a trick at the beginning of the universe, and – unfortunately for defenders of non-epiphenomenal consciousness and free will – it’s a trick that agents seemingly also need to perform every time they exercise free will. They have to introduce or create some new event that is neither random nor wholly dependent on prior physical causes.

However, modern science has put that axiom under pressure, leading us to question whether it really is such a self-evident truth. It’s not that science has shown that matter or energy can be created ex nihilo (indeed, that would violate another key idea in physics; that of the conservation of energy enshrined in the first law of thermodynamics) but rather that modern science now suggests that the very concept of nothingness may be meaningless.

The quantum fields that make up the universe, such as the electromagnetic field and the Higgs field all have a ground state – a lowest possible energy configuration – slightly above zero, making them subject to quantum fluctuations. This is the case even in a complete vacuum, hence the name vacuum energy, although the property as applied to each field is known as zero point energy. But a vacuum is the only physical (i.e. non-abstract) definition of nothingness that makes sense within the bounds of the universe, so physically-speaking there is no such thing as nothing.

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Because excitations in quantum fields are one and the same as point particles in the standard model, this vacuum energy manifests as the creation of virtual particle/antiparticle pairs that briefly pop into existence and immediately annihilate each other. This fact applies not only to the vacuum or to space, but to every part of the universe. This vacuum energy can be thought of like the fizzing surface of a liquid, with each bubble being that brief pair of particles that burst into existence only to almost immediately pop out of it again, although it is important to note that this energy is usually both unmeasurable and unavailable to macroscopic processes – it is not some mystical energy field one can use to justify belief in dubious phenomena!

In technical terms, these particles exist for a time shorter than the Planck time, which means that due to the time-energy relationship in Heisenberg’s uncertainty principle, they remain unmeasurable and insubstantiated in the physical world. Hence the label virtual particles as opposed to actual particles we can measure.

However, just because they are virtual, one shouldn’t imagine that they play no role in the physical world. Not only have experiments shown them to be most-likely responsible for proven phenomena such as spontaneous emission, the Casimir effect, and the Lamb shift, but they are also generally thought to mediate the interaction of real particles in quantum field theory. For example, the exchange of virtual photons underlying the interaction of electrons in electromagnetism.

The only way these virtual particles can achieve actualisation and gain any kind of permanence is to draw on the energy in the surrounding environment, whilst avoiding mutual annihilation.

One situation in which this is thought to be possible is in the extreme environment of a black hole. These gravitational sink-holes bend space so severely that even the fastest moving objects in the universe – photons of light – do not have sufficient escape velocity to avoid falling into their clutches. This results in the formation of a boundary, or event horizon, from which no matter or energy can escape.

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Now consider a particle/antiparticle pair that forms at the event horizon of a black hole. In simple terms, if one of the pair forms inside the event horizon and the other on the outside, then they will not be able to interact and annihilate, and drawing on the gravitational energy of the black hole, they actualise. So both an observer on the interior of the horizon, and one on the outside witness the emission of particles as radiation. This is known as Hawking radiation after physicist Stephen Hawking who first conjectured its existence.

As previously stated, this isn’t really ex nihilo creation of matter or energy, because the creation process is driven by the intrinsic zero point energy of quantum fields, plus the energy of the surrounding system. Thus the principle of conservation of energy also means that the system involved must lose some of its own energy, or in the case of black holes the equivalent mass. In this way black holes starved of infalling matter are though to slowly but surely evaporate.

Another consequence is that the more mass or energy a system has, the greater the mass or energy of the particles that can be emitted. So whilst there are also hypothesized micro black holes, produced primordially in the early universe and perhaps still existing today, the Hawking radiation they would emit would consist only of low mass particles like electron/positron pairs or photons, which are massless and their own antiparticles. (Note that even in normal black holes, Hawking radiation is dominated by photons).

But black holes are not the only situation where this type of particle creation can occur. In theory, any energetic phenomena that forms an event horizon can perform the same trick.

One such phenomenon is known as the Unruh effect, and is a logical consequence of Einstein’s realisation that the gravitational force is equivalent to acceleration. Here an accelerating system gains kinetic energy from the gravitational field which then – from the point of view of an observer in the same relativistic reference frame as the accelerating system  – results in a radiation bath in that internal frame, as particle/antiparticle pairs actualise before annihilating. And just like the black hole case, because an accelerating system creates an event horizon (the reason for which is beyond the scope of this piece), the equivalent of Hawking radiation is also witnessed by observers outside that horizon.

In both examples, we have the formation of an event horizon creating a one-way barrier between an enclosed volume of space (the interior of the black hole and the relativistic reference frame) and the rest of the universe.

So, returning to consciousness, we have – superficially at least – an interesting parallel. In both, the external environment can influence the enclosed internal worlds via the flow of information into them, but from within those enclosed internal worlds one is only able to observe the external universe rather than interact directly with it. However, via a phenomenon such as Hawking radiation, that internal world is able to exert a physical influence back on its environment. By analogy, these phenomena correspond to a mechanism for non-epiphenomenal consciousness.

Now, I’m certainly not suggesting that consciousness resides in microscopic black holes – I’ll leave that to Romulan starships! Nor am I saying that the Unruh effect is responsible. I simply don’t have enough knowledge of physics or mathematics to surmise or calculate how small objects at short distances may or may not produce the acceleration necessary or an event horizon local enough. And I strongly doubt there is anything in mainstream neuroscience to offer as a framework for such effects in the brain.

I’m only suggesting that such seemingly ex nihilo creation would not-so-long-ago have been thought impossible without supernatural intervention in the world, but that zero point energy opens-up the possibility of a variety of effects that might – at least conceivably – be exploited by evolved systems.

Under those speculative lights, the mere possibility of horizon-enduced particle creation in connection to consciousness and the brain would provide a high-level explanatory mechanism for non-epiphenomenal consciousness. And if such creation could be directed and (perhaps chaotically) amplified, one might see how such internally-produced nudges might pave the way for free will.


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At such low energies, any such creation would have to be in the form massless particles like photons, and whilst this might bring its own problems in accounting for how they might deliver the needed nudges to existing processes, on the other hand, such effects should in principle be measurable and therefore testable. It should be noted that there is already some speculation about the role of photons in the brain, though stressed that this is not mainstream.

Of course, even if there is something in my speculation, many issues might remain unresolved, such as the hard problem of consciousness and how the mental domain might manage to muster and direct its will; not to mention under what ontology and laws consciousness itself might operate internally.

Also, there is danger here in stepping too far with speculative ideas. Scientists and rational thinkers are wary of any non-physicalist speculation on consciousness, I suspect because to do so opens the door to all sorts of religious and pseudoscientific nonsense that are neither objectively testable or even subjectively universal. So it’s important to not speculate more than a single step beyond our current knowledge, and to do so without any preconceptions of where one is heading.

But with that caution in mind, I still think it’s fair to say that this class of phenomena in physics at least shines a light into the domains in which we should search for clues. And even if such speculation proves fruitless, it serves to illustrate how science continually surprises us with unexpected phenomena. So while admitting that the existence of non-epiphenomenal consciousness and free will remain improbable, we should not lose hope. Closing the door on what are our most universal and all-encompassing experiences of reality – that our minds interact with and affect the physical world – is premature.

To be free again? How free will is not dead yet.

[NOTE – this is re-post from the original incarnation of this blog.]

The New Scientist website is running an interesting article on a recent experiment that casts further doubt on the non-existence of free will. You can read the original article here.

If the possibility that your decisions are not free comes as a shock to you, it’s worth considering that from a purely scientific point of view, our current understanding of how the universe works at a fundamental level leaves absolutely no room for anybody or anything to be a self-creating causal agent.

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The reason for this is that the known laws of classical physics are deterministic, and even if you discard these in favour of the more fundamental laws of quantum physics, you find that the only non-deterministic part of the theory, namely the wave function in the Schrödinger equation, only throws a component of complete randomness into the mix, and frankly, complete randomness is no better for free will than complete determinism.

So back in the 70s, when Benjamin Libet studied the brain during free decision making and found correlated activity before the volunteers reported they had made the conscious decision, some interpreted this as good evidence that free will was indeed just an illusion created by the mind.

That’s not to say that huge numbers of scientists necessarily take that view. The majority of scientists are practical people who simply follow the evidence and avoid interpreting their results too much, an approach that some refer to as “shut up and calculate”. Most are content to leave any metaphysical speculation to philosophers and armchair commentators like myself.

But among philosophers themselves, there are probably many of a physicalist persuasion who previously looked to Libet’s results as supporting their view, and that line of evidence looks like it’s beginning to disappear. This includes those of the compatiblist view, which for me is the same as saying there’s no free will at all.

Personally, I believe that the hypothesis that free will is an illusion is an extraordinary one in the face of all our subjective experience to the contrary, and that, to quote Carl Sagan, “extraordinary claims require extraordinary evidence”.

For me, free will should be assumed to exist, even if that means we need to accept that something major is missing or incorrect in our understanding of fundamental physics. And since consciousness itself is still far from being fully integrated into our understanding, there is still plenty of room.

The whole subject of consciousness, free will, and fundamental physics fascinates me, and there’s a whole host of literature by philosophers who deny it exists and those that would like to preserve it. I see this as philosophy at it’s most useful, probing the edge of our scientific understanding, and suggesting ideas on what logic dictates could be possible against what’s not.

I hope to write a lot more on this subject in more detail when I have time, hence the lack of links in that last paragraph. So hang on to your armchairs! ;)