Chapter 3Free Will and Determinism

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3.1-2

The Problem of Free Will and Determinism

How is free will possible given that every event seems causally determined?

What is it to have free will? Can we be held responsible for our

actions if we have no free will?

3.1-3

Free Androids

Could a robot have free will? Could a robot be found guilty of

murder? Robots only do what they’re

programmed to do. But according to psychologists, we only do what we’re programmed to do by nature (genes) and nurture (environment).

So do we have free will?

3.1-4

Clarence Darrow on Free Will “What had this boy to do with

it? He was not his own father; he was not his own mother; he was not his own grandparents.”

“Do you mean to tell me that Dickie Loeb had any more to do with his making than any other product of heredity that is born upon the earth?”

3.1-5

Causal Determinism

According to causal determinism, every event is the consequence of past events plus the laws of nature.

We can’t change the past and we can’t change the laws of nature.

If everything that happens is the result of things over which we have no control, how can we have free will?

Section 3.1The Luck of the Draw

Freedom as Chance

3.1-7

Hard Determinism

Hard determinism claims that there are no free actions.

The argument from causal determinism: (1) Causal determinism is true.

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

3.1-8

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?

3.1-9

The Consequence Argument

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

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

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

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

3.1-10

Incompatibilism

According to incompatibilism, causal determinism is incompatible with free will—both cannot be true.

In other words, if causal determinism is true, no one acts freely.

3.1-11

Causal 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.

3.1-12

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?

3.1-13

Thought Probe: The Book of Life Suppose a Laplacean

superbeing wrote a book that chronicles your life from beginning to end.

Now suppose you read the book.

Can you do other than what the book says? If so, does that show that you have free will?

3.1-14

Science and Determinism: The Nature/Nurture Debate

Which has a greater effect on our behavior: nature or nurture?

Advocates of nature: the primary determinant of our behavior is what’s encoded in our genes.

Advocates of nurture: the primary determinant of our behavior is how we’re brought up.

Both parties agree that our behavior is determined by forces beyond our control.

3.1-15

Psychological Behaviorism

The view that behavior is determined by conditioning.

Psychologist B.F. Skinner: “Personal exemption from a complete determinism is revoked as a scientific analysis progresses.”

Early behaviorists, like John B. Watson, thought that human behavior was totally determined by how one was nurtured: “Give me a dozen healthy infants…and I’ll

guarantee to take any one at random and train him to become any type of specialist I might select.”

3.1-16

Thought Probe: Behavior Modification

Suppose that by instituting a program of behavior modification in our prisons, we could cut the recidivism rate in half and save society billions of dollars.

Should we do it? Why or why not?

Peter Zuehlke, Brad Mays

3.1-17

Sociobiology

The view that behavior is determined by what’s encoded in our genes.

So if we want to change behavior patterns, we’ll have to modify people’s genetic makeup.

3.1-18

Thought Probe: Genetic Engineering Suppose the sociobiologists are correct

that our psychology is shaped by our genes.

Suppose further that we have the technology to alter our genes.

Should we use that technology to alter our genes? Could a hard determinist object to such a modification?

3.1-19

Thought Probe: Faking Free Will

Psychologists have found that a belief in determinism caused an increase in immoral behavior.

If science succeeds in showing that there is no free will, should we nevertheless pretend that we have free will? Could we do such a thing?

3.1-20

Thought Probe: Defending Determinism

Some think determinism is self-refuting because if it’s true, no one believes anything because they have a good reason for believing it. (They believe because they’ve been caused to believe.)

So if determinism is true, no one can have a good reason for believing it’s true.

Is this a good reason for rejecting determinism?

3.1-21

Quantum Indeterminism

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.

3.1-22

Thought Experiment: Gardner’s Random Bombardier

Some think that indeterminism is limited to things on the microlevel.

Gardner disagrees: “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 has a significant effect on events at the macro-level.

3.1-23

Common Sense and Causal Determinism

Some think 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 rejects causal determinism.

3.1-24

Thought Probe: Living with Hard Determinism

Suppose that the hard determinists are right and there is no free will.

How would we have to change society to accommodate that fact? What social institutions would we have to abolish or create? Could we do it? Why or why not?

3.1-25

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—many different possible futures could become actual.

3.1-26

Indeterminism

The doctrine that free actions are uncaused.

In this view, many possible futures are open to us.

3.1-27

Thought Experiment: Taylor’s Unpredictable Arm

Can uncaused actions be considered free actions?

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.

So it seems that uncaused actions can’t be considered free actions.

3.1-28

Causality and Action

An uncaused event can’t be a free action because actions require intentions. For example: reflexes are not actions

because you did not intend for them to happen.

If you didn’t intend something to happen—if it was an accident, say—you can’t be held fully responsible for it.

3.1-29

Thought Experiment: Newcomb’s Paradox Suppose a being who has accurately predicted

your behavior in the past offers you the following decision problem involving two boxes:

Box 1 contains $1000 while box 2 contains either $1 million or nothing depending on what the being predicted. (If he predicts you’ll choose both boxes, he puts nothing in the second box, if he predicts you only choose box 2, he puts the $1 million in it.)

The money is already in the boxes. Would you choose both boxes or only the second box?