The Problem of Free Will

What Is

The problem of free will is one of the most persistent problems in philosophy: the appearance of a deep conflict between the freedom we take ourselves to possess and the causal order of the natural world. Stated as an inconsistent triad, the problem runs as follows. First, we ordinarily suppose that at least some of our actions are free, in the sense that we could have done otherwise and that the origin of the action lies in us. Second, the scientific image of the world suggests that every event, including every human action, is the necessary consequence of prior events together with the laws of nature. Third, these two claims appear to be incompatible: if my action was inevitable given the state of the world before I was born, in what sense did I choose it, and in what sense could I have done otherwise?

The problem of free will is not merely the question whether determinism is true; it is the question what would follow if it were. Even a philosopher who thinks determinism is false must explain what freedom consists in, and why indeterminism would help. The problem therefore has two faces: the threat that determinism leaves no room for freedom, and the difficulty of saying what freedom would have to be for there to be a genuine conflict at all.

Historical Background

The ancient Greeks posed the problem in terms of fate and necessity. The Stoics defended a compatibilist response: even if everything is fated, our actions remain ours because they proceed from our own natures and assent. In the Christian era, Augustine and Aquinas confronted the distinct problem of divine foreknowledge: if God knows what we will do, must we not do it? Their answer — that foreknowledge does not cause the future — anticipated the compatibilist strategy of distinguishing necessity from compulsion.

The modern problem takes its characteristic form from physics. Laplace's demon — an intellect that knows every force and position and can compute the entire future — made vivid the idea of a fully determined universe. David Hume responded that the problem is a verbal one: liberty is the power to act according to the determinations of the will, and this is compatible with necessity, since "necessity" names nothing more than the constant conjunction of causes and effects. Immanuel Kant found Hume's solution unacceptable, arguing that morality requires a transcendental freedom that Hume's account dissolves.

In the twentieth century the debate was given its contemporary form. Peter van Inwagen formulated the consequence argument, which tries to show rigorously that if determinism is true, we have no power over our actions, since they are consequences of the past and the laws, over which we have no power. Daniel Dennett and others responded that determinism does not imply inevitability, and that the freedom worth wanting is a matter of the agent's capacities, not of a gap in the causal order.

Key Concepts

The consequence argument. Van Inwagen's formal argument: if determinism is true, then our present actions are consequences of the remote past together with the laws of nature; we have no power over the remote past or the laws; therefore we have no power over our actions. It is the strongest case that determinism threatens freedom.

The principle of alternative possibilities. The thesis that an agent acts freely only if she could have done otherwise. Harry Frankfurt's counterexamples — cases in which an agent would have been compelled had she not chosen, but she chooses freely on her own — challenge this principle and the argument built on it.

The two-stages of the modern debate. The conflict is now typically framed as a debate among three families: hard determinism (deny freedom), libertarianism (deny determinism's reach), and compatibilism (deny the incompatibility). Each family contains subtle subdivisions, such as reason-responsiveness accounts and event-causal versus agent-causal libertarianism.

Libertarian vs compatibilist freedom. Libertarians require that the agent have had genuine alternatives in a robust, indeterministic sense. Compatibilists, by contrast, analyze freedom in terms of the agent's psychological and practical capacities — acting on one's reasons, responding to incentives, being uncoerced — which do not require any break in causation.

Moral responsibility as the stake. The problem of free will is not an idle puzzle, because our practices of praise, blame, reward, punishment, gratitude, and resentment presuppose that agents could have done otherwise and are answerable for their actions.

Contemporary Relevance

The problem of free will has become a live interdisciplinary question. Neuroscience, beginning with Benjamin Libet's experiments, has produced evidence that neural activity precedes conscious decisions, and the interpretation of this evidence continues to be contested: some see it as showing that free will is an illusion, while others argue that it only shows that conscious decisions are not uncaused. Behavioral genetics and developmental psychology reveal the causal origins of dispositions and characters, challenging the picture of the self-created agent. Legal scholars debate whether responsibility and punishment survive a determinist conclusion, and experimental philosophers study the ordinary concepts of choice and blame that legal and moral practice presuppose.

At the same time, the philosophical options have multiplied. Compatibilists have developed sophisticated accounts of freedom as reason-responsiveness; hard incompatibilists such as Derk Pereboom argue that neither determinism nor indeterminism can ground responsibility, and defend a revised, non-punitive moral practice; and revisionists argue that we should keep responsibility while giving up the metaphysical baggage. The problem of free will is thus not a closed debate but an open research program at the center of philosophy.

Sources

1. O'Connor, T. & Franklin, C. (2021). "Free Will." Stanford Encyclopedia of Philosophy. https://plato.stanford.edu/entries/freewill/
2. Hoefer, C. (2016). "Causal Determinism." Stanford Encyclopedia of Philosophy. https://plato.stanford.edu/entries/determinism-causal/
3. Eshleman, A. (2019). "Moral Responsibility." Stanford Encyclopedia of Philosophy. https://plato.stanford.edu/entries/moral-responsibility/
4. McKenna, M. & Coates, D. J. (2021). "Compatibilism." Stanford Encyclopedia of Philosophy. https://plato.stanford.edu/entries/compatibilism/
5. Kane, R. (ed.) (2002). The Oxford Handbook of Free Will. Oxford University Press.

Related Topics

• The terms of the problem are defined in the discussions of what free will is, what determinism is, and what compatibilism is.
• The moral stakes of the problem are examined in the discussion of moral responsibility and in free will and the law.
• Dennett's defense of the freedom worth wanting is the subject of the quote dennett-on-free-will.
• The free will topic collects the debate's many facets, from quantum mechanics to self-control.
• The Understanding Reality collection situates the problem within the metaphysics of causes and laws.