that mean for society, morality, meaning, and the law? Could society properly function without belief in free will? These are just some of the questions to be debated in this book.
To begin, it’s important to introduce some key terms and positions. First, we can say that free will, as contemporary philosophers tend to understand it, is the control in action required for a particular kind of moral responsibility. More specifically, it’s the power or capacity characteristic of agents, in virtue of which they can justly deserve to be blamed and praised, punished and rewarded for their actions. Understanding free will as linked to moral responsibility in this way, anchors the philosophical debate in something comparatively concrete and undeniably important to our lives. As Manuel Vargas notes: “This is not a sense of free will whose only implication is whether it fits with a given philosopher’s particular speculative metaphysics. It is not a sense of free will that is arbitrarily attached to a particular religious framework. Instead, it is a notion of free will that understands its significance in light of the role or function it plays in widespread and recognized forms of life” (2013: 180).
Contemporary theories of free will can be divided into two general categories: those that endorse and those that are skeptical of the claim that human beings have free will. The former category includes libertarian and compatibilist accounts of free will, two general views that defend the claim that we have free will but disagree on its nature or its conditions. The latter category consists of a class of skeptical views that either doubt or deny the existence of free will. The main dividing line between the two pro-free will positions, libertarianism and compatibilism, is best understood in terms of the traditional problem of free will and determinism. Determinism, as it is commonly understood, is the thesis that at any given time only one future is physically possible (van Inwagen 1983: 3). Or put differently, it’s the thesis that facts about the remote past in conjunction with the laws of nature entail that there is only one unique future (McKenna and Pereboom 2016: 19). Indeterminism, on the other hand, is the denial of this thesis – it’s the claim that at some time more than one future is physically possible. The traditional problem of free will and determinism therefore comes in trying to reconcile our intuitive sense of free will with the idea that our choices and actions may be causally determined by factors over which we have no ultimate control, that is, the past before we were born and the laws of nature.
Historically, libertarians and compatibilists have reacted to this problem in different ways. Libertarians (not to be confused with the political view) acknowledge that if determinism is true, and all of our actions are causally determined by antecedent circumstances, we would lack free will and moral responsibility. Yet they further maintain that at least some of our choices and actions must be free in the sense that they are not causally determined. Libertarians therefore reject determinism and defend an indeterminist conception of free will in order to save what they maintain are necessary conditions for free will – the ability to do otherwise in exactly the same set of conditions and/or the idea that we remain, in some important sense, the ultimate source/originator of action. Compatibilists, on the other hand, set out to defend a conception of free will that can be reconciled with determinism. They hold that what is of utmost importance is not the absence of causal determination, but that our actions are voluntary, free from constraint and compulsion, and caused in the appropriate way. Different compatibilist accounts spell out requirements for free will differently but widely endorsed views single out responsiveness to reasons, self-control, or connection of action to what one would reflectively endorse.
In contrast to these pro-free will positions are those views that either doubt or outright deny the existence of free will and moral responsibility. Such views are often referred to as skeptical views, or simply free will skepticism. In the past, the leading form of skepticism was hard determinism: the view that determinism is true and incompatible with free will – either because it precludes the ability to do otherwise (leeway incompatibilism) or because it is inconsistent with one’s being the ultimate source of action (source incompatibilism) – hence, no free will. For hard determinists, libertarian free will is an impossibility because human actions are part of a fully deterministic world and compatibilism fails to reconcile determinism with free will. Hard determinism had its classic statement in the time when Newtonian physics reigned supreme and was thought to be deterministic. The development of quantum mechanics, however, diminished confidence in determinism, for the reason that it has indeterministic interpretations. This is not to say that determinism has been refuted or falsified by modern physics, because a number of leading interpretations of quantum mechanics are consistent with determinism. It is also important to keep in mind that even if we allow some indeterminacy to exist at the micro-level of the universe, say the level studied by quantum mechanics, there may still remain determinism-where-it-matters – i.e. at the ordinary level of choices and actions, and even the electrochemical activity in our brains. Nonetheless, most contemporary skeptics tend to defend positions that are best seen as distinct from, but as successors to, traditional hard determinism.
Many contemporary free will skeptics, for instance, maintain that while determinism is incompatible with free will and moral responsibility, so too is indeterminism, especially if it is limited to the sort posited by certain interpretations of quantum mechanics. Others argue that regardless of the causal structure of the universe, we lack free will and moral responsibility because free will is incompatible with the pervasiveness of luck. Others still, argue that free will and ultimate moral responsibility are incoherent concepts, since to be free in the sense required for ultimate moral responsibility, we would have to be causa sui (or “cause of oneself”) and this is impossible. Here, for example, is Nietzsche on the causa sui:
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 profoundly and frightfully 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 Munchhausen’s audacity, to pull oneself up into existence by the hair, out of the swamps of nothingness. (1886/1992: 218–219)
The one thing, however, that all these skeptical arguments have in common, and what they share with classical hard determinism, is the belief that our choices, actions, and constitutive characters are ultimately the result of factors beyond our control – whether that be determinism, chance, or luck – and because of this we lack the kind of free will needed to hold agents morally responsible in the relevant sense.
List of Useful Definitions
Determinism: The thesis that facts about the remote past in conjunction with the laws of nature entail that there is only one unique future.
Compatibilism: The thesis that free will can be reconciled with the truth of determinism – i.e. it is possible for determinism to be true and for agents to be free and morally responsible in the relevant sense.
Incompatibilism: The thesis that free will cannot be reconciled with determinism – i.e. if determinism is true, free will is not possible.
Libertarianism: The thesis that incompatibilism is true, that determinism is false, and that some form of indeterminist free will exists.
Free Will Skepticism: The thesis that no one has free will, or at the very least, that we lack sufficient reason for believing that anyone has free will.
Hard Determinism: The thesis that incompatibilism is true, that determinism is true, and therefore no person has free will.
Hard Incompatibilism: The thesis that free will is incompatible with both determinism and indeterminism – i.e. that free will is incompatible with both causal determination by factors beyond the agent’s control and with the kind of indeterminacy in action required by the most plausible versions of libertarianism.