The debate about which triumphs, free will or determinism, can on many occasions feel so unsatisfying. Over the years I’ve picked up or have come across quite a few pieces of literature on the subject, from historical and social studies to psychological research, neuro and cognitive science, and also various speculations within philosophy and physics. It is a debate that is hotly contested from both sides – a longstanding philosophical matter of concern.

Through history philosophers and scientists have organised arguments around numerous points of empirical validation. On the one hand, human beings can affect change. The human subject – consciousness and all – has the ability to change social and economic structures, protest and revolt in the face of tyrants, and conceive of novel inventions that will forever shape civilisation. Imagination, creation, the impulse to explore and discover, and the ability to deviate from established patterns and social norms – these are all cited as examples that support some idea of free will.

Moreover, that a person could, spontaneously and on a whim, decide to paint a picture of melting clocks in a desert simply because they can, and because they have the ability to imagine and philosophise about such radical symbolism, could be construed as an act of free will. Jean-Paul Sartre famously argued from the basis of two well-known aspects of human experience in this regard: choice and responsibility. With some concept of free will comes both freedom of choice and responsibility of action (and for one’s actions), two qualities that are argued to be of basic human experience. The assumption, of course, is that free will exists. On the other hand, Sartre, the master of existentialism and 20th century notions of freedom and the subject, also conceded at the heart of his philosophy that the situation is complicated. There are many more forces at play that extend beyond pure unadulterated free will. Hence, he employed the term “facticity”. This term represents all of that sociohistorical-cultural stuff that exists external to the individual subject – economy, cultural norms, social and individual psychology, and so on. In other words, he recognised all of these things – the stage in which one pursues life – as also playing a significant role in fostering subjectivity and in suggesting, in my own words, certain sets of probabilities in behaviour. Human choice, in other words, is delivered within a historical context – the range of things that comprise that context extend or constrict the horizon of possibility. This is similar, in some ways, as considerations one might read within biology texts about how or in what ways biology and culture may become entangled and thus affect one another.

Sartre is just one philosopher of a long list that argues toward some notion of free will – or rather, the mediating subject which is, as I take it, more nuanced that the traditional idea of free will. He does so within a set of certain constraints, similar, indeed, to likes of Adorno and others. But Sartre serves as a particularly useful example because, on the other hand, there is also a strong argument for some notion of determinism. On the level of the human, not only is there all that social, historical and cultural stuff that contextualises the stage of one’s existence – some even refer to the “economic horizon of possibilities” – but there are also worthy scientific concerns and speculations that would contradict any argument toward the idea of pure and unadulterated free will.

Contemporary cognitive and neuroscience rightly have a growing voice on these matters. Indeed, in my opinion, the answer likely lies within a better understanding of both the human brain and mind. One plausible estimate is that there are 86 billion neurons in the human brain. We’re speaking of an inconceivable amount of cells, not to mention synapse, of which up to one-hundred thousand can be associated with just one neuron. Factoring in brain chemistry – and biochemical processes more generally – notions of unadulterated free will become less likely. The likelihood then constricts even more given the role psychology and emotions play in human experience, and how these may then relate to the brain – not to mention how the social, cultural and economic contexts may affect the development of the brain. (For example, there is emerging evidence that suggests things like poverty affect a child’s brain development). But even on a purely physical level: consider something so simple as two people talking with one another, or interacting in some way. This situation is dependent also on the laws that atoms behave in a certain way in this situation, that electrons behave in a certain way – the interaction depends on chemical forces, electrical forces, and even forces of gravity and so on. It is easy to just see two people talking, conscious and engaged, conceiving of new thoughts and imaging new future topics of conversation. It is a common daily image to witness two or more people engaging in conversation over tea or a meal. But there are so many dimensions or factors to this interaction as well as to each individuals behaviour in that moment of interaction, it is difficult to fix the idea of free will because almost immediately the context and complexity of the engagement demands focus.

We could substitute the word “dimensions” for what the great physicist Richard Feynman would describe as interconnecting hierarchies – a sequence of relative hierarchies, their connections and interconnections, from the elaborate complexities of fundamental particles quantum mechanics to atoms and then microbes and biochemistry and the ~100 billion neurons firing in the brain; then constantly higher to perception, motor control, memory processes, psychology, emotions, prejudices, and social concepts and then also established norms of social interaction, and so on. When thought of in this way, with the complexity of interacting and interconnected hierarchies, it is difficult to not only find sense in the idea of unadulterated free will but it is also difficult to follow or trace the complex causal chain that would define a tangible concept of determinism, even in a simple situation of two people conversing with one another. Just the operation of the visual cortex of the brain alone, with its many excited neurons, as light reflects off objects in one’s field of view, entering the eye (a complex optical refracting system and photodetector). As the light passes through the cornea and to the retina, light sensitive cells cause photochemicals to decompose, sending necessary electrochemical signals to the brain that then stimulate the visual cortex. Although a gross simplification – without even mentioning the greater complexity of the human eye, the millions of rods and cones in the retina, or even the million nerve fibres connecting the eye to the brain – the point is that each subtle moment in even the most basic experience of two people talking is filled with an inexplicable amount of interconnected processes. How to account for all of this in the context of free will or, for that matter, causal chain determinism?

Indeed, and moreover, we can think of this example of two people talking and compare it with a study of patients undergoing brain surgery while still awake. This might sound strange at first. But it is an interesting example because, while undergoing surgery, it is not uncommon that the patient may lie awake and play their favourite instrument or recite their favourite maths, so as to be sure that the particular part of the brain associated with the patient’s favourite activity in life may not be damaged. It is also the case that, in such instances of brain surgery, it has been found that electrical stimulation to the relevant areas of the brain can cause the patient to move their hand or exercise a certain muscle. With this direct link between stimulation and action, it is difficult to speak of free will or even agency. One of my favourite passages currently on these debates comes from the late Professor Stephen Hawking in Grand Design (2010), who also cites similar examples of patients undergoing brain surgery. He writes, in one part of his book, “the molecular basis of biology shows that biological processes are governed by the laws of physics and chemistry and therefore are as determined as the orbits of the planets…so it seems that we are no more than biological machines and that free will is just an illusion” (p. 32). Later, he writes, “Quantum physics might seem to undermine the idea that nature is governed by laws, but that is not the case. Instead it leads us to accept a new form of determinism: Given the state of a system at some time, the laws of nature determine the probabilities of various futures and pasts rather than determining the future and past with certainty” (p.72; emphasis added).

With everything that has already been noted, and in taking seriously Professor Hawking’s argument, how might we proceed?

If we return to the example of two people talking and interacting, perhaps over a cup of coffee, one enlightening point of study involves the new science and emerging conceptual picture of complexity and networks. In other words, I think it can be said that human behavior can be modeled as a complex system. Unlike particles, human beings respond to history . In fact, every single moment of human experience is based on a fermenting and simmering cocktail of interacting factors. Consider the relation of the brain to the body and vice versa – it seems a mistake to liken the brain purely to a machine, and frontier neuroscience certainly sheds light on this error. Less mechanical and predictable, the brain is equally dependent on genes that make proteins, which then enable a brain cells to communicate with another brain cells. These cells then of course manufacture or establish circuits, the basis then of macro brain structures, and so on. In the instance of two people communicating verbally with one another, or simply one person perceiving an object, a multitude of interacting parts are at play, some of which I have already alluded. The complexity of human experience is then only complicated further when we consider the subject’s unceasing interaction with their environment – some philosophers and scientists describe this through the notion of intentionality. But even more complex yet, throughout ones entire life genes are constantly being switched on and switched off, the brain is also constantly receiving biochemical signals and triggers as chemicals are released, while biochemical forces can trigger emotions or other response patterns or behavioural patterns. It is, again, a fermenting and simmering cocktail of interacting chemistry and active neurons, in addition to more superficial aspects such as emotions and psychology, which, in every moment, plays some role in human behaviour. It is becomes even more complex when we consider the nurturing and developmental aspect of things like human emotions, in which a great deal of psychology elaborates, including how healthy and positive emotional development can lead to increasing capabilities for rational and logical considerations to overcome emotional responses. Not only does all of this deepen questions or valid enquiries into the state or status of determinism with respect to a conscious human being; it most certainly dampens, in my view, any idea of free will.

Rather than thinking in terms of simple systems or of interactions within simple systems – or simple mechanical models of behaviour – even in the example of two human beings interacting at a coffee house, science from across numerous disciplines seems to suggest a picture of where we’re now converging more with the need of having to think in terms of complexity (or even networks).

To approach the issue from another angle: if the notion of free will is being brought into question here, perhaps impliedly another point of enquiry that emerges concerns the status of choice and responsibility. Indeed, the implications in moral philosophy about the absence of free will are well known. Informed scientific debates have existed for decades, including within the legal realm. But as this discussion relates to Prof. Hawking’s view, perhaps it depends on one’s interpretation or conceptualisation of determinism? I mean, the idea of libertarian free will would seem an “illusion” in many ways; but what of the general idea of human agency? What of the idea of the free-flourishing human subject? How might, instead, the notion of probabilistic determinism offer a language, or a way of conceptualising, that in some way preserves the idea of determinism while acknowledging the computational mechanism of the subject of the human agent? I think these are very interesting questions to ask, which, likewise, raise very interesting ideas that are worth considering.

I suppose what I am encircling in a very informal way is how, on a purely physical level, we can most certainly say that what we have is two human beings with each human being comprised of a certain configuration of particles and atoms that obey the laws of physics. In that there is physical reason to argue for a new form of determinism, this also serves an interesting question. How can such a new form of determinism fit within a complex picture of human behaviour?

For example, in the illustration of two people speaking with one another, perhaps over a cup of coffee, one could ask: did they choose to drink that coffee or was their behaviour determined? But what if there is a third explanation: what if there is a certain probability that the individual will drink a cup of coffee or will not? How do we fit this question into a complex picture of human behaviour keeping in mind, also, the empirical argument for an interacting subject?

One might argue, like some philosophers do in relation to the “soul”, that free will is entangled in the self-stimulation of electrical signals – in knowledge, and observation, and thus in reason which can overcome purely biochemical motivations. One might argue, alternatively, that on the basis of quantum theory and moving up the conceptual hierarchy, determinism is the most accurate explanation for human reality, made complicated with the existence of consciousness of which we have yet to really understand. I think these types of considerations are helpful in that the longstanding stalemate in the debate between free will and determinism is due to how it has so often become limited to the entrenched ontological distinction between materialist views and dualistic views. In my opinion, this is negatively restricting. Instead, when considering all the current best arguments in addition to the weight of the physical evidence, I am left thinking: perhaps the reality is more convoluted, more nuanced – that our lack of certainty and inability to conclusively reconcile the concepts of free will, or agency, and determinism is a measure of our ignorance. In other words, what if the answer is neither a 1 or a 0. What if there is some mechanism for computation and for some mediating agency in making decisions whilst also some mechanism of determinism? How can we stretch our conceptual vocabulary to make sense of the physical nature of human beings and what we observe in terms of behaviour and psychology in the context of interacting systems?

It is similar, in a certain sense, to the ongoing debates between process metaphysics and substance metaphysics. Both positions offer valuable arguments, and also serve their own respective substantial empirical and logical case as evidence. But what is most interesting – and perhaps this is another example of the value of the march of science – both of these debates are making their way into contemporary physics. And among all the speculations within theoretical physics about the correct interpretation of quantum theory, perhaps it is that there is process in substance and, reversely, substance in process. Relatedly – even if only by analogy – when we take the weight of all the arguments, perhaps it is fruitful to ask whether some notion of free will – or mediated agency, which is different than traditional notions of pure free will which still does justice to the computation factor and to agency – can exist within a physical theory of determinism? In physics, building from the uncertainty principle, there implies in uncertainty some idea of freedom from a traditional hard determinism. Instead, from one vantage, we are looking at the potential of probabilistic determinism. (A site of interesting consideration here can be found in the study of the path integral – or of particle paths more generally. To give historical context, Albert Einstein was famously cautious about quantum theory as currently conceived, primarily because he saw probabilistic determinism as evidence of an incomplete picture. Instead, the idea was that there are variables still hidden from us, mathematically and experimentally. This is what gives meaning to Einstein’s remark, “I am convinced God does not play dice”. On the flip side, there is quantum contextualism and Bell’s famous theorem that counter this notion of hidden variables).

Of course, these last comments point back to the frontier sciences and what we strive to know. Fascinatingly, the debate of free will versus determinism has some connection.


To conclude, it should be said that there is a great deal more still to be said on these matters. What I will end with here is a simple acknowledgement that the topics at hand are incredibly interesting and certainly important. I do not mean to offer any formal argument, but simply to suggest certain questions that might be raised. Disagreements pertaining to determinism versus free will arise in so many different research contexts, it is difficult to not find reason for stimulated curiosity.  In terms of my own perspective, I would say that what is encouraging is that the question of free will or determinism is become increasingly scientific. As for my own arguments, I currently argue toward some idea of probabilistic determinism. I have often expressed some argument toward some notion of causality, and I would be inclined to suggest that the case for some sort of determinism is overwhelmingly strong – that is, a determinism given the state of a system at some time. Human beings are comprised of atoms and other things that obey the laws of physics. To speak as a human being as if there is no determinism would seem foolish. But what if we begin thinking in terms of networks and systems, as some biologists are beginning to do? I think it leads to a very different idea of determinism compared with traditional or classical notions of deterministic thinking. Is there a wider analogy that one might offer? In this manner of wording, the idea would seem to be not that different to the concept of “facticity” mentioned earlier – a concept also given many different names by many philosophers and social scientists. It’s also a concept one will find, however it may be expressed, within places like developmental and behavioural psychology – the idea that the subject is mediated with its sociohistorical-cultural conditions. But I am currently thinking of these ideas in the background of strictly mathematical and physical study. It is interesting to point out, for example, that many mathematical models of physical systems are deterministic. There are also mathematical models that are not deterministic – stochastic – and there are those that are chaotic, with an interpretation of the latter and its implications still very much open. In chaos theory, it may actually prove impossible to predict outcomes in complex systems – perhaps including systems involving consciousness – and this may or may not offer some statement about the parameters or limits of determinism. It also remains that deterministic systems – even very basic systems or models using differential equations – can be sensitive to their initial conditions (much like with chaotic systems), giving the false appearance of non-determinism.

Using these insights to offer wider analogies is difficult. But, as things currently stand, probabilistic determinism would not seem unfathomable. We have not even scratched the surface of arguments in physics and biology and elsewhere, while on the level of human experience, there is also intriguing empirical examples that might be raised: it is interesting to consider how given a current state – or situation – and even preserving some space for human agency, it is entirely possible to predict a person’s behaviour if you know them well enough (given the probabilities of their action). Think, for instance, of insights offered by way of cognitive behavioural therapy – the existence of established thought patterns and triggers to certain stimuli. In other words, a person’s behaviour may not be absolutely determined or determinable, but there is still a certain probability or predictability. Of course people can change their behavioural patterns, alter or change the ways in which they think. After all, the assumption is that some space for agency is preserved and in preserving some space for agency absolute knowledge is forbidden. But the probability of a person’s behaviour, given a certain situation or context against which such probability may be judged, is likely not out of reach. If I know that a person is hungry and that they like apples, then when experiencing hunger and situated around some apples, the likelihood is that they will opt to eat an apple. Or, if a person is known to be triggered by a certain stimuli, there is a sense of predictability or at least predictable probability that such stimuli will act as a behavioural trigger. One may think, furthermore, of Bayes theorem or think of studies regarding predictive models of consumer behaviour. Indeed, it does not seem outrageous to suggest some predictability – even conditional probability – about a person’s behaviour given prior knowledge of conditions and some definition of familiarity with that person: a knowledge of that person, their psychology, history, and motivations over time, etc. In the very least, probabilistic determinism is interesting to think about from a number of perspectives. In a not so subtle way, some of the ideas also remind me of certain insights offered by predicative coding theory in which it would seem possible that both the idea of determinism and the idea of the mediating subject might coalesce. The only problem is that, once again, the coordinates of the point where these two concepts might intersect remains largely undefined.