What Is Hard Incompatibilism?

Direct Answer

Hard incompatibilism is the position, developed most fully by Derk Pereboom, that the kind of free will required for what he calls "basic desert" moral responsibility cannot exist — because it is incompatible with determinism, and equally incompatible with the leading alternatives to determinism. Basic desert is the idea that a wrongdoer deserves blame and punishment simply in virtue of being the morally responsible agent who did wrong, independent of any forward-looking goal such as reform or deterrence. Hard incompatibilists argue that no account of the world, deterministic or indeterministic, supplies the kind of ultimate authorship that basic desert demands.

The key distinction is between hard incompatibilism and its two relatives. Hard determinism denies free will because determinism is true. Libertarianism affirms free will by denying determinism. Hard incompatibilism is the more sweeping position: even if the world turned out not to be deterministic — even if quantum randomness permeated the brain — the free will worth wanting would still be missing. Indeterministic events would give us chance, not control; random neural noise is no better a ground for desert than causal necessity. The only difference from hard determinism is dialectical: hard incompatibilism is stronger, because it does not depend on the empirical truth of determinism.

The position is best illustrated by Pereboom's "four-case argument," a series of cases that begins with a person whose behavior is manipulated by neuroscientists, passes through progressively less direct forms of manipulation and conditioning, and ends with ordinary deterministic causation. Pereboom argues that there is no morally relevant difference between the first case and the last: if the manipulated agent is not morally responsible, neither is the ordinary agent under determinism. The cases make vivid the intuition that our ultimate causal history is never "up to us."

Historical Context

Hard incompatibilism is a late-twentieth-century refinement of the older hard determinist tradition. Its ancestry runs through Spinoza and d'Holbach, who denied free will on deterministic grounds, and through the skeptical strand of the free will debate represented by Arthur Schopenhauer, who quipped that a person can do what he wills but cannot will what he wills. What is new in Pereboom is the systematic treatment of the indeterminism option and the careful account of what survives the loss of free will.

The position also grows out of Galen Strawson's "Basic Argument," which tries to show that self-origination is impossible in principle: to be truly morally responsible for your actions you would have to be responsible for your character, and to be responsible for your character you would have to have created it, which would require an infinite regress. Pereboom's hard incompatibilism absorbs this lesson while keeping its feet in the analytic debate about determinism, manipulation, and the conditions of responsibility. It has become one of the three or four standard positions taught in the contemporary free will literature, alongside libertarianism, compatibilism, and hard determinism.

Key Arguments & Debates

The central argument is the four-case argument described above. Its engine is the "no difference" intuition: add a little manipulation, remove a little, and you cannot find a principled line where responsibility suddenly switches on. If neuroscientists covertly implant desires in a person and she acts on them, she is clearly not responsible. If the same desires are produced by early conditioning, then by genes, then by plain ordinary physics, the hard incompatibilist insists that no morally relevant line has been crossed. The argument targets compatibilism directly, because compatibilists typically hold that an agent is responsible when she acts from her own desires in the absence of compulsion — and the manipulated agent satisfies that condition while still seeming excused.

The main objections come from compatibilists. They argue that the manipulation cases are disanalogous: a manipulator is itself an agent with a plan, and being the instrument of another's design is different from being caused by blind nature. They also argue that responsibility is about the actual character of the agent at the time of action — whether her behavior is responsive to reasons — not about the distant history of how that character was formed. Pereboom replies that the notion of "reasons-responsiveness" is itself satisfied in the manipulation cases, which shows that the compatibilist criterion cannot be sufficient for basic desert. The debate therefore turns on whether responsibility is forward-looking (a practice justified by its consequences) or backward-looking (a judgment about what an agent ultimately deserves) — and hard incompatibilism is defined by the claim that the backward-looking notion is empty.

Contemporary Relevance

Hard incompatibilism has practical consequences that make it more than a technicality. If basic desert is an illusion, then retributive punishment — punishing because offenders deserve it — is unjust, and the criminal justice system should be rebuilt around prevention, incapacitation, rehabilitation, and compensation. Pereboom defends a "quarantine" model: just as we isolate carriers of dangerous disease without blaming them, we may isolate dangerous people without retributive blame. In the age of AI, the position also feeds debates about algorithmic decision-making: if human choices are products of causes we do not ultimately control, then responsibility gaps in automated systems become less anomalous. Neuromarketing, predictive policing, and legal doctrines of diminished responsibility all presuppose judgments about control and desert that hard incompatibilism calls into question — making the position increasingly relevant to law, ethics, and technology policy.

Related Concepts

• Hard Determinism: the position hard incompatibilism extends by denying the indeterminism option.
• Libertarianism: the rival view that freedom requires indeterminism.
• Compatibilism: the rival view that freedom survives determinism.
• The Consequence Argument: the incompatibilist argument hard incompatibilism inherits.
• The Manipulation Argument: the family of arguments the four-case argument belongs to.
• Moral Responsibility: the concept whose desert-based form is rejected.

Further Learning

• Derk Pereboom, Living Without Free Will (2001).
• Stanford Encyclopedia of Philosophy: Free Will
• Stanford Encyclopedia of Philosophy: Moral Responsibility