Chapter 3 Free Will and Determinism 1

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? 2

Section 3.1 The Luck of the Draw Freedom as Chance 3

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. 4

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? 5

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. 6

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. 7

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. 8

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? 9

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.” 10

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. 11

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. 12

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. 13

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. 14

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? 15

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. 16

Indeterminism Indeterminism is the doctrine that free actions are uncaused. In this view, at any point in history, there are many possible futures. 17

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. 18

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.) 19