Free Will

Do people have free will?

“The most contentious question of metaphysics, the most contentious science” (David Hume)

Big Picture
Nature of Free Will
  • Is free will …
    • being able to choose among alternatives?
    • being able to have done otherwise had you wanted, chosen, or tried to?
    • being able to have done otherwise under the same conditions?

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Classical Determinism

Classical Determinism is the thesis that every event is determined by laws of nature and antecedent conditions.

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Neural Determinism

Neural Determinism is the view that free will is incompatible with the operation of the brain.

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Psychological Determinism

Psychological Determinism is the claim that human actions are determined by psychological laws, e.g. the Law of Strongest Motive.

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Quantum Probability

Quantum Probability is the claim that free will is incompatible with the probabilities predicted by Quantum Mechanics.

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Arguments for Free Will
  • Self-Evidence
    • During deliberation it’s self-evident to a person that they can choose any option under consideration.
  • Moral Responsibility
    • People are morally responsible for some of their actions.
    • A person is morally responsible for an action only if they can act otherwise.
    • Therefore, people can sometimes act otherwise.
  • Making a Virtue of Necessity
    • What’s rational to believe must be believable.

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Principle of Alternate Possibilities

The Principle of Alternate Possibilities (PAP) is that people are morally responsible only if they could have done otherwise.

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  • People believe they have categorical free will, that they could have done otherwise under conditions at the time.
  • Moral responsibility requires categorical free will.
  • Thus, having categorical free will matters to people.
  • Neural Determinism and Quantum Probability are incompatible with categorical free will.
  • There is substantial evidence supporting Neural Determinism and Quantum Probability.
  • There is no compelling argument for categorical free will.
  • Hence there is substantial evidence that a belief that matters to people – that they could have done otherwise under the conditions at the time – is false.