Chapter 3Free Will and Determinism

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Causal Determinism

• Causal determinism is the doctrine that every event has a cause that makes it happen.

• But if everything, including every act, has a cause, how is it possible for persons to have free will?

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Section 3.1The Luck of the Draw

Freedom as Chance

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Hard Determinism

• Hard determinism is the doctrine that there are no free actions.

• (1) Causal determinism is true.(2) If causal determinism is true, there are no free actions.(3) Therefore, there are no free actions.

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Thought Experiment: Laplace’s Superbeing

• “Given for one instant an intelligence which could comprehend all the forces by which nature is animated…the future and the past would be present to its eyes.”

• If it is, in principle, possible to predict everything we will ever do, how can we have free will?

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The Consequence Argument

• (1) If causal determinism is true, then every event is the consequences of past events plus the laws of nature.

• (2) We are powerless to change past events, laws of nature, or their consequences, which include our actions.

• (3) If we are powerless to change our actions – if we can’t do otherwise – then we can’t act freely.

• (4) Therefore, if causal determinism is true, we can’t act freely.

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Incompatibilism

• Hard determinists are incompatibilists because they believe that causal determinism is incompatible with free will.

• They also believe that causal determinism is incompatible with moral responsibility.

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Determinism and Moral Responsibility

• (1) If causal determinism is true, we can’t act freely.

• (2) If we can’t act freely, we can’t be held responsible for our actions.

• (3) Therefore, if causal determinism is true, we can’t be held responsible for our actions.

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Thought Probe: Freedom and Foreknowledge

• Many believe that God is all-knowing, which means He knows the future.

• If God knows the future, can there be free will? Why or why not?

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Science and Determinism

• Some believe that science has shown that hard determinism is true.

• Psychologist B.F. Skinner, for example, claims, “Personal exemption from a complete determinism is revoked as a scientific analysis progresses.”

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The Nature/Nurture Debate

• The nature/nurture debate is about which factor has a greater effect on our behavior.

• Those who favor nature claim that the primary determinant of our behavior is what’s in our genes.

• Those who favor nurture claim that the primary determinant is how we’re brought up.

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Quantum Indeterminism

• Although both science and common sense are said to confirm causal determinism, neither does so.

• Physics has found that some events, for example, those at the sub-atomic level, have no cause.

• So the doctrine of causal determinism is false.

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Thought Experiment: Gardner’s Random Bombardier

• “Imagine a plane [carrying] a hydrogen bomb that is dropped by a mechanism triggered by the click of a Geiger counter.”

• Here an event on the micro-level can have a significant effect on events at the macro-level.

• So indeterminacy is not necessarily confined to the micro-level.

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Common Sense and Causal Determinism

• Some believe that we can’t understand the world unless causal determinism is true.

• But quantum mechanics gives us an unprecedented understanding of the physical world and it admits the existence of uncaused events.

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Thought Probe: Genetic Cleansing

• Suppose that sociobiologists discover the genes that influence our psychology.

• Suppose further that we can alter those genes through genetic engineering.

• Should we use this technology? Why or why not?

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Causal Indeterminism

• The view that some events are not the consequence of past events plus the laws of nature is known as causal indeterminism.

• In this view, the future is not fixed.

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Indeterminism

• Indeterminism is the doctrine that free actions are uncaused.

• In this view, at any point in history, there are many possible futures.

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Thought Experiment: Taylor’s Unpredictable Arm

• Suppose that Taylor’s arm movements are undetermined or random.

• If his arm hit someone, he wouldn’t be responsible for it because he didn’t cause his arm to move.

• This possibility shows that uncaused actions can’t be considered free actions.

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Causality and Action

• An uncaused event can’t be a free action because where there is no intention, there is no action.

• To be held responsible for an action, you must have caused it (or failed to prevent it.)

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