In philosophy, libertarians defend the kind of free will that the vast majority of people take for granted, that is, the kind of free will that makes us responsible for our actions—and thus for our lives—in a deep and meaningful sense. However, libertarians are a small minority amongst philosophers, who, for the most part, believe that this kind of free will is not possible or even intelligible, and that it has no place in our modern scientific picture of the world. How could something that is so deeply ingrained in our psyche and that pervades every aspect of our lives be nothing more than a product of our minds, nothing more than an intricate fantasy? As the 20th century writer Isaac Bashevis once quipped, ‘You must believe in free will; there is no choice.' Be this as it may, can a belief in libertarian free will be justified on rational, philosophical grounds?
From the outset, it is important to distinguish the libertarian in matters of free will from the libertarian in matters of politics, who essentially believes that governments should circumscribe their roles to protecting individual liberties, so long as these individual liberties do not interfere with the individual liberties of other individuals. The free will libertarian does not necessarily share in the political libertarian’s societal ideal; however, there is a clear sense in which the political libertarian relies upon the existence of libertarian free will, which he implicitly takes for a given. Thus, if a belief in libertarian free will cannot be justified on philosophical grounds, nor can a belief in libertarian politics, in criminal justice, or in many other things besides.
Why do most philosophers believe that libertarian free will is impossible? Given the physical state of the universe at any given point in time, and given the laws of physics which are universal and constant, (1) it is impossible for the past or future history of the universe to be any other than it is, and (2) it is theoretically possible to map out every single past and future event in the universe. In other words, all past and future events are written out in the very fabric of the universe. This so-called ‘causal determinism’ came to life in the form of a demon dreamt up some 200 years ago by the mathematician and astronomer, the Marquis de Laplace. By knowing every single physical fact about the universe, this super-intelligent being could accurately predict the future simply by applying Newton’s laws. Newtonian physics has since been superseded by quantum mechanics, which allows for chance or indeterminism in the behaviour of elementary particles. Even so, quantum mechanics has not put away with traditional concerns about causal determinism because (1) even if quantum mechanics is not one day to be superseded by a more comprehensive deterministic theory, indeterminism in the behaviour of elementary particles need not translate into indeterminism in human behaviour and, (2) even if it did, the human behaviour that resulted would be random and unpredictable rather than free and responsible. In short, whilst free will appears to be incompatible with determinism, it also appears to be incompatible with indeterminism!
A widespread response to the problem posed by determinism is so-called ‘compatibilism’, according to which ‘freedom’ is (1) the ability to do something and (2) to be unimpeded in doing it. Thus, I am free to cook a soup if I have the ability to cook a soup, but I am not free to cook a soup if, for example, I do not have the time, ingredients, or equipment to do so, if I am called out in an emergency, or if an intruder is holding me at gunpoint. According to the 17th century philosopher Thomas Hobbes, who was a compatibilist, a person is free when ‘he finds no stop in doing what he has the will, desire, or inclination to do’. And if this is freedom, then a person is free even if what he has the will, desire, or inclination to do happens to have been determined. Of course, it might be objected that freedom involves not just the ability to do something, but also the ability to do otherwise. The compatibilist response to this objection is to define ‘the ability to do otherwise’ in the same way that he defined ‘freedom’: ‘the ability to do otherwise’ is (1) the ability to do otherwise and (2) to be unimpeded in doing it. If I had wanted to do otherwise than cook a soup, nothing would have impeded me from doing so. However, I did not want to do otherwise than cook a soup (because what I wanted to do had been determined), and in that sense I was free. As ‘the ability to do otherwise’ has a conditional or hypothetical meaning, it is not strictly speaking incompatible with determinism.
Whilst the compatibilist account seems to capture surface freedoms—freedoms such as taking the bus, buying a packet of lentils, or turning on the gas—which involve nothing more than the ability to do or not to do something, it does not seem to capture the freedom of choice that most people equate with free will. When people talk about ‘free will’, they do not just mean ‘unconstrained choice’, but also control over that choice. However, compatibilists believe that this kind of deep or libertarian free will is simply incoherent: the same past cannot lead to more than one possible future, and that is pretty much the end of the story. Imagine that Emma, who is in the final year of her degree course, is deliberating between a career in teaching and one in investment banking. After giving it much thought, she ‘chooses’ to have a career in investment banking. Given the same past—the same beliefs and desires, the same thought processes, the same prior deliberation—how could Emma possibly have ‘chosen’ differently? The only way that Emma could have chosen differently is if her past, that is, the past, had been different. However, the past could not have been different for the simple reason that there is only ever one past. Even if Emma could have chosen differently, this choice would have been arbitrary and inexplicable given the same beliefs and desires and so on. In conclusion, says the compatibilist, it is not just that most people have a confused notion of freedom, but also that they have a confused notion of determinism, which they confound with constraint or compulsion. Unfortunately, helping them to clear up their confused notions does not bring them round to compatibilism, because what they fundamentally believe is that determinism is in itself incompatible with free will. In short, they are incompatibilists.
To make matters worse, it is not just that libertarian free will appears to be incompatible with determinism, but also that it appears to be incompatible with indeterminism. If undetermined events such as quantum leaps occur by chance, and if free actions are undetermined events, then free actions also occur by chance. This is an obvious contradiction in terms, since free and responsible actions cannot, by definition, occur by chance. If my actions result from nothing more than undetermined events in my brain, then they are impulsive and unpredictable, and undermine rather than enable my freedom. Imagine that I am deliberating between a fast-food meal and a healthier but more time-consuming home-cooked meal, and that after some thought and deliberation, I choose the home-cooked meal. If my choices are undetermined, I might suddenly and inexplicably choose the fast-food meal despite going through exactly the same process of thought and deliberation. One might argue, as did the 17th century philosopher Gottfried Leibniz, that prior reasons or motives do not determine choice or action, but merely ‘incline without necessitating’. However, it is precisely because prior reasons and motives inclined me towards the asparagus risotto that I chose it over the double cheeseburger; had I chosen the double cheeseburger, my choice would have been arbitrary and inexplicable rather than deliberate and responsible. Another way of looking at this problem is to imagine that I have a counterpart, Neel*, who lives in an alternative possible world which is in all respects identical to this one. One day, I succumb to the temptation to steal a bicycle, whereas Neel* successfully resists this temptation, even though both of us have had exactly the same past up till that point. In the words of the contemporary philosopher Alfred Mele, ‘If there is nothing about the agents’ powers, capacities, states of mind, moral character and the like that explains this difference in outcome ... the difference is just a matter of luck.'
If libertarians are to hold that free will is compatible with indeterminism, they need to provide an account of how we might be able to act and act otherwise without it seeming inexplicable, irrational, capricious, or arbitrary. To do this, many libertarians postulate the existence of an additional factor such as the mind or soul that is beyond the physical world and thus beyond the laws of physics or nature. Although the mind or soul is beyond the physical world, it is able to intervene in the physical world to influence physical events, for example, by exploiting the indeterminism in the brain. In other words, whilst undetermined events in the brain may not in themselves account for free choices, they might provide the ‘point of engagement’ for an additional factor such as the mind or soul to influence physical events. Some libertarians believe that such a Cartesian dualism of mind and body is the only possible solution to the problem of free will, but many others are sceptical. Leaving aside traditional concerns about mind–body dualism, it is not even clear that mind–body dualism is an appropriate response to the threat of indeterminism: if Emma’s choice to have a career in investment banking is no longer determined by the prior physical activity of her brain, then it is determined by the prior activity of her disembodied mind or soul. In short, mind-body dualism appears to achieve little more than to shift the problem to one remove, that is, from the brain to a (hypothetical) mind or soul. All that is left to the dualist libertarian is to appeal to mystery and to claim that disembodied minds or souls are beyond the reach of our understanding. This was, in fact, the line adopted by the 18th century philosopher Immanuel Kant, who believed that the existence of libertarian free will was presupposed by our practical and, in particular, by our moral lives. Kant held that science and reasoning can tell us about how things appear in the world (‘phenomena’), but not about how they are in themselves (‘noumena’). Whilst phenomena are subjected to the constraints of scientific or theoretical reasoning, noumena such as our noumenal selves that govern our practical and moral reasoning are not, and therefore cannot be understood in terms of scientific or theoretical reasoning. Unsurprisingly, many libertarians are just as unconvinced by Kant’s reasoning as they are by Cartesian mind–body dualism.
Another ‘additional factor’ strategy advanced by some libertarians is the so-called agent-causal strategy, according to which Emma is able to act or act otherwise because her acts are caused not by prior events (determinism) nor by chance (indeterminism), but by Emma herself (self-determinism). This type of ‘immanent’ causation induced by the agent herself differs from the ‘transeunt’ causation induced by prior events in that it involves a ‘prime mover unmoved’. Unfortunately, many libertarians think that agent-causation or immanent causation is no less mysterious than Cartesian mind–body dualism or Kantian noumenal selves, and that, like Cartesian mind–body dualism and Kantian noumenal selves, it merely shifts the problem to one remove, in this case to a prime mover unmoved, uncaused cause, or cause of itself (causa sui), and thus to something akin to God. However, it seems unlikely that mere human beings can be moved without being moved, that is, without being moved at least in part by a range of physical, psychological, and social factors. The final word on the matter seems to go to the 19th century philosopher Friedrich Nietzsche, who wrote,
The causa sui is the best self-contradiction that has been conceived so far; it is a sort of rape and perversion of logic. But the extravagant pride of man has managed to entangle itself…with just this nonsense. The desire for ‘freedom of the will’ in the superlative metaphysical sense, which still holds sway, unfortunately, in the minds of the half-educated—the desire to bear the entire and ultimate responsibility for one’s actions oneself, and to absolve God, the world, ancestors, chance, and society—involves nothing less than to be precisely this causa sui and, with more than Baron Munchausen’s audacity, to pull oneself up into existence by the hair, out of the swamps of nothingness.
In short, libertarians have had a hard time defending the kind of free will that makes us responsible for our actions in any deep and meaningful way. Their appeals to various mysterious ‘additional factors’ such as the mind or soul to explain the possibility of our being uncaused causes of ourselves seem unconvincing. The question arises, as to whether libertarians are able to provide an account of free will that does not make appeal to mysterious forms of agency, but that sits comfortably with our scientific picture of the world.
One possibility is this. Neuroscience has suggested that electrical signalling in the brain is subject to quantum indeterminacies. Such indeterminacies could translate into undetermined patterns of neurological activity which could provide sufficient latitude for the exercise of free will. Of course, such undetermined patterns of neurological activity would be random, and could not of themselves account for free will, which requires not only alternative possibilities but also free choices. According to chaos theory, small changes in the initial conditions of a physical system can trigger increasingly large events, and can lead to enormous and unpredictable changes in that system’s behaviour. For example, the flap of a butterfly wing in Kyoto could, at least in theory, provoke a violent thunderstorm in Paris. Similarly, an effort of thought or concentration could act on undetermined patterns of neurological activity in the brain and result in an undetermined action, and thereby to the exercise of free will. Most of the time, a person’s actions and the neurological activity that they result from would be determined by past events and the cumulative effects of those past events on that person’s patterns of thinking. For example, most of the time a person’s actions would be determined by a complex amalgamation of addictions, phobias, neurosis, obsessions, enculturation, socialisation, learned behaviour, and so on. However, on certain occasions, such as when a person was genuinely torn between two competing and potentially life-changing choices, the degree of indeterminacy in his brain would rise to such a high level as to permit an undetermined action. Such a window of freedom would be more or less rare, but could exert a profound effect on all subsequent determined and undetermined actions. For example, if Emma had made an undetermined choice to go for a career in teaching rather than in banking, she would, amongst many other things, have had a very different set of friends. She would have married a man whom she would not otherwise have met. Together they would have had ‘other’ children, almost certainly in another house, perhaps in a different city, perhaps even in a different country, and so on.
An important and intuitively correct corollary of the ‘effort of thought’ theory of free will is that some people are freer than others. First, people who are less prone to set patterns of thinking such as those involved in addictions, phobias, neurosis, obsessions, enculturation, and socialisation are freer than those who are more prone to them. Some rare people actively seek to escape from set patterns of thinking, thereby increasing the amount of background indeterminacy in their brain and thus the number of opportunities for making undetermined choices. In so doing, they are ascending a virtuous spiral in which the more they escape from set patterns of thinking, the more opportunities they have for exercising free will, and the more opportunities they have for exercising free will, the more they escape from set patterns of thinking. In short, freedom begets freedom. Second, people who can ‘see into the future’, that is, people who have a high degree of insight into the potential ramifications of the choices that they face, are freer than people who cannot or will not see into the future, either because they are lazy or stupid, or, more commonly, because they are afraid to accept responsibility for the choices that they face, and so believe that and behave as though they do not face any. Of course, there is a high degree of overlap between people who are prone to set patterns of thinking and those who cannot or will not see into the future, since both conditions ultimately arise from the same source, namely, fear, and both conditions are mutually reinforcing of each other. Conversely, there is a high degree of overlap between free thinkers and visionaries. In the game of life as in the game of chess, the best players are those who can see several moves ahead, and who can respond to ever changing circumstances with the boldest and most original moves.
See also my video blog, Jean-Paul Sartre on Bad Faith