Free will

The capacity to choose and to have been able to choose otherwise - and whether anything answers to that description.

Theme: Mind, self and consciousness
Tradition: Cross-tradition
Term fixed: c. 397

In plain terms

Two things seem obviously true and cannot both be, at least not without work.

The first is that you could have done otherwise. You chose tea, and nothing was stopping you choosing coffee. The second is that every event has causes, and your choice was an event in a brain in a world, which means it followed from prior conditions you did not choose - your genes, your history, the state of your neurons a second earlier.

There are three ways out. Deny the second, and say some choices are not fully determined. Deny the first, and accept that the sense of an open future is an illusion. Or deny that they conflict, and argue that being free was never about escaping causation but about acting from your own reasons rather than under compulsion. All three are held by serious people, and the third is the majority position among philosophers.

As a philosopher would put it

Incompatibilists hold that free will and determinism cannot both obtain. Libertarians take free will to be real and determinism false; hard determinists take determinism to be true and free will an illusion. Compatibilists hold that the conflict is apparent, and that freedom is a matter of acting from one's own desires without external constraint - Hume's version - or, on Frankfurt's more demanding account, of one's effective desire being one the agent endorses at a higher level.

Frankfurt cases are the key move against the could-have-done-otherwise requirement. If a device would have intervened to produce the same choice had you wavered, but never activates because you choose it anyway, then you could not have done otherwise and appear fully responsible - which separates responsibility from alternative possibilities.

The theological version came first and is structurally identical: reconciling divine foreknowledge with human freedom occupied Augustine, Boethius, al-Ashʿarī and Aquinas, and Boethius's answer - that God's knowledge is timeless rather than prior - remains one of the more elegant moves in the subject.

Where you meet it

In 1983 Benjamin Libet asked subjects to flex a wrist whenever they felt like it, and to note the position of a dot on a clock face at the moment they became aware of the urge. He recorded the readiness potential in motor cortex, which builds before movement.

The readiness potential began about 550 milliseconds before the movement; the reported awareness of deciding came about 200 milliseconds before it. The brain, on the face of it, had started the action before the person knew they had chosen. Soon and colleagues reported in 2008 that patterns in prefrontal and parietal cortex predicted a left-right choice up to several seconds ahead, though only slightly above chance.

The experiments are contested in every direction - the timing method, what the readiness potential is, whether spontaneous flexing resembles a decision at all, and Schurger's 2012 argument that the signal is accumulating noise crossing a threshold rather than a decision being made. What is not contested is that the results are inconclusive, which is itself informative: the most direct experiment anyone has designed on the question did not settle it.

What is actually disputed

Whether compatibilism answers the question or changes it.

Compatibilists argue that the freedom worth wanting is freedom from compulsion, not freedom from causation, and that the incompatibilist demand is incoherent - an uncaused choice would be random, and randomness is not control. Incompatibilists reply that this substitutes a weaker notion for the one at issue, and that if every one of your choices was fixed before you were born then saying you could have done otherwise is simply false, however comfortable the redefinition.

Hard incompatibilists such as Pereboom accept the conclusion and argue that we should give up desert-based blame while keeping forward-looking practices of protection and reform - a position with direct consequences for punishment. Meanwhile the empirical question of whether determinism is even true is unsettled, and it is not clear that indeterminism would help if it were false.

Commonly confused with

political freedom Liberty from interference by others is a different subject entirely. A prisoner may have free will and no political liberty, and the reverse is equally possible.
the feeling of choosing That the deliberation feels open is not evidence that it is. The feeling is exactly what a determined system that models its own options would produce.

Defined against

Determinism The pair defines the problem, and the entire literature is about whether they are genuinely opposed

Philosophers

Augustine of Hippo Where the freedom of the will becomes a distinct question
Boethius Divine foreknowledge reconciled with freedom by timelessness
David Hume Liberty as absence of constraint, not absence of causation
Immanuel Kant Freedom as a postulate of practical reason, not an object of knowledge
Baruch Spinoza Men think themselves free because they know their desires and not their causes

Works

Confessions The will divided against itself
The Consolation of Philosophy Foreknowledge and freedom
A Treatise of Human Nature The compatibilist reduction
Critique of Pure Reason Freedom as a necessary idea rather than a fact
Ethics The denial, and its explanation of why the illusion is universal

Schools

Augustinianism Where the problem is set
Thomism Where the theological version is systematised
British Empiricism Where compatibilism is formulated
Spinozism Where free will is denied outright
Ash’arism The Islamic parallel debate over acquisition and divine power

Related concepts

Agency c. 340 BC · Responsibility c. 340 BC · Determinism 1677 · Will c. 397 · Autonomy 1785

The Greeks discuss voluntariness without framing a problem about the will; Augustine, needing to locate the origin of evil in creatures rather than God, makes the freedom of the will a distinct question.