Bryan Caplan  

Testing the Freedom to Choose

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Jane Galt relays a challenge to believers in free will (myself among them) from Scott Adams:

It seems to me that free will can be easily tested. The next time someone is getting brain surgery, just take a few minutes to perform the test. Sometimes the patient remains awake during brain surgery so he can report what functions are changing as the surgeon is poking around. So for example, when the surgeon electrically stimulates the language center of the brain, the patient might temporarily lose his ability to speak.

[...]

If the patient can speak normally despite having the speech center stimulated, then the patient has free will that can overcome the normal chain of cause and effect in the brain. If he can’t speak, then you have proven the brain is nothing but a moist and complicated machine and your life is a pointless series of miseries.

Talk about a stacked deck. What believer in free will has ever thought that you are free to choose no matter what? Why not just give people lobotomies to "prove" there's no free will?

Conversely, it's clear that if the believer in free will passed Adams' test, determinists would just say that the speech center didn't get enough electricity.

In the end, what the determinists have going for them is the axiom of causality. And what believers in free will have going for them is virtually all of our waking experience. Decades after first hearing both sides of this debate, I still choose ubiquitous introspection over a plausible a priori postulate.


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COMMENTS (17 to date)
Dain writes:

I was reading in the new issue of the Economist something about the theory of Free Will being challenged by our increasing understanding of neuroscience. Excessive Anger, rather than a bad habit, is simply a genetic predisposition. Thus, said the article, one of the main rationales for punishment is undermined.

But even if this were proven to be true it doesn't really get us anywhere, because those who would seek to unjustly punish people that "can't help it" are themselves beholden to a certain level of determinism. And it seems quite possible that a certain amount of punishment, shorn of any metaphysical theory of morals, is still a useful corrective to a predetermined level of bad behavior anyway.

Urstoff writes:

Introspection reveals nothing about the possibility of a libertarian freewill. Our own introspection (having deliberations and choices) is fully compatible with determinism. What would it seem like to a computer if it had a limited monitoring of its own internal states? Maybe it would seem very much like what our own experience seems like.

And let's not be too eager to throw out deterministic causation, especially since quantum indeterminacy probably has no effect on the workings of neurons (Penrose's hopes remain just hopes).

Third, let's think about evolution. If a libertarian freewill isn't ubiquitous in nature, and it can't be a deterministic result of genes and environment interacting, is the acquisition of freewill in our evolutionary history the miracle to end all miracles?

Patri Friedman writes:

I agree with Urstoff - introspection is a pretty weak argument. If I could program a computer to act human, I could certainly program it to think it had free will too.

invcit writes:

I'm pretty shocked that you call causality just a plausible a priori postulate. All physical experiments are consistent with causality. It is an experimental question that has been settled to a high degree of accuracy, not just a postulate. While it remains a possibility that somehow it is not valid in quantum gravity, that would not be manifested until you energies high enough to probe distances small as the Planck length, which is very, very far removed from our everyday experience. Introspection, on the other hand, is known to not always be a reliable source of information. Look at people who believe they have seen UFOs, for an example.

William Newman writes:

"All physical experiments are consistent with causality"? Only if you are willing to postulate remarkably complicated mechanisms to explain them, I think.

There are many experiments where the result matches the predictions of quantum mechanics, and where the predictions of QM depend strongly on "the wavefunction collapsing at the moment of measurement." A famous example of such an experiment is the double-slit interference
pattern created by a particle beam even when the particle beam is so faint that one would expect a vanishingly small probability of two particles in the apparatus at once. Before the measurement, the probability amplitude acts like a wave. After the measurement, you get behavior that is more like a single particle randomly sampled from a probability distribution which is the square of the probability amplitude. Granted the QM model is quite bizarre, but mathematically it is fairly simple, and it gives an extremely accurate match to the real world. As far as I know, such experimental results strongly resist explanation by deterministic models. You can make a deterministic model which explains the experiment, but it ends up being so much more complicated than the QM model that one is reminded of pre-Copernican epicycles upon epicycles upon epicycles.

RogerM writes:

Scott Adam's experiment sounds credible only because it's cloaked in neuroscientific language. You could restate the experiment by asking the subject to speak after you cut off his head.

No one who accepts free will believes that a will exists outside of and independent from the body. Even fundamentalist Christians, such as myself, believe that the body and soul are so tightly woven together as to be indistinguishable from each other. Death occurs when the body and soul become separated, usually at the moment that the body quits functioning.

We also believe that the brain (usually referred to as the flesh in the Bible) has certain pre-wired tendencies, such as the desire to survive, eat, sleap, have sex, love, etc. But while the Creator intended those "drives" for good, we have another pre-wired tendency to distort them, which causes what we call evil. Survival tendencies can lead us to theft, murder or war; sex to rape; eating to gluttony, etc.

Free will comes into play with our ability to resist the evil side of those biological drives and reinforce the good side. The apostle Paul has a great passage in the book of Romans, chapter 7 I believe, where he anguishes over the fact that the good that he knows and wants to do he finds difficult to accomplish because of his flesh (in neuroscience, brain).

RogerM writes:

I've been reading more about neuroscience lately, especially Pinker, and since this is the Christmas season, neuroscience and the divinity of the Christ child collided in my brain. Fundamentalist Christianity has always taught that Jesus was 100% man and 100% God, a real mystery. But at the same time, His divinity was "cloaked" by his humanity. In other words, Jesus wasn't born knowing everything. He still had to go to school and obey His parents. He was tempted in every way like we are, but He didn't sin; that's where His divinity peaks through. His divinity leaks through in the few miracles He performed and His resurrection, but the rest of the time He was as trapped and limited by this body and brain as the rest of us. Neuroscience helps me appreciate more fully how restricting and frustrating this body must have been for Him.

Matt writes:

The problem for determinists is the same for the atheists. Who is the prime mover? There is no such thing as a perpetual motion machine.

How do people learn if the world is deterministic? You must believe that quantum physics was "taught" to man by rocks and birds, or that every man is born with knowledge of quantum physics but cannot access it. In determinism, there is no original thought, just the bombardment of ideas like millions of monkeys on a typewriter.

On the other hand, if you believe in free will, then man- like God- can act upon the system and introduce new ideas.

RogerM writes:

Matt: "How do people learn if the world is deterministic?"

Good question! Determinists don't seem to explain how we can learn anything new, much less how that new learning can contradict inherited traits. In fact, the process of socialization is nothing but the attempt to overcome our genetic predispositions. Saving, self-control, respect for others, are all learned. No one has to teach a child to be selfish, angry, present-oriented, or violent.

Mr. Econotarian writes:

Neural networks and other learning machine models are able to extract patterns from input based on generic learning routines. Determinism does not limit a machine from learning.

Urstoff writes:

Everyone here (or at least the above two posters) seem to be confusing physical determinism with genetic determinism. Deniers of freewill only hold the former, not the latter. Physical determinism holds that every physical state is determined by the previous physical state and the laws of nature. Genetic determinism holds that behavioral traits are a direct result the genes. Thus, genetic determinism has nothing to do with the possibility of a libertarian freewill. Locke's blank slate method of learning and personality development is completely compatible with physical determinism, but quite contrary to genetic determinism. Genetic determinism (like Locke's blank slate) is trivially false. Physical determinism, however, seems to hold true at every level of matter save the quantum mechanical. To hold a belief in a libertarian freewill is to hold to an indeterminism at a much higher level than the quantum mechanical, namely, the neural. There is to date zero evidence for indeterminism at this level, so, no matter what confused introspection might say, the prospect of a libertarian freewill is quite grim.

Omer K writes:

Science and the concept of free will are diametrically opposed. Science looks for causality...free will denies it.

Science will say..genes cause it or environment causes it...or randomness causes it. All of these are deterministic.

Science can undermine the belief of a free will...but it can never destroy it. So what? Its an old story, an old paradox. You can either accept that we are all machines, or not.

In either case, dressing the whole thing up in "debate" is futile.

Brad Hutchings writes:

Sigh. You guys are all getting way deeper than Scott Adams waded into this... He does this about once a month, probably because it gets the most comments and traffic of all his recurring subjects.

This is the one place I completely agree with Ayn Rand and her intellectual heirs... When we talk of free will, we are working in the area of philosophy -- personal philosophy. People's thoughts are built atop skyscrapers of abstractions, which are convenient ways to avoid rethinking. When a high level decision doesn't mesh with reality (e.g. you run a drill through your hand), it's your responsibility to back up and figure out the erroneous abstraction that got you there and fix it. And that's really the essence of free will, the magic of it. Few of us have the time to do more than react as moist robots (as Adams calls us) to day to day situations. But we all have the ability to evaluate good and bad decisions and figure out why we made them, and change our reactive thinking. Funny how that's a central tenant of any recovery program that would obviously be targeted to the weakest among us, and yet we have people seriously disputing whether free will exists. Blows my mind!

RogerM writes:

Mr. Econotarian: Neural networks and other learning machine models are able to extract patterns from input based on generic learning routines. Determinism does not limit a machine from learning.

The fallacy in your analogy lies with different definitions of learning. The "learning" that neural networks do is not even close to what we mean when we say humans learn. All neural nets do is pattern replication. Human learning enables us to choose between competing impulses, resist earlier learning, and create new ideas.

This quote from Mises on behavioral psych is relevant to this issue of determinism, too:

Behaviorism fails to explain why different people adjust themselves to the same conditions in different ways. Behaviorism proposes to study human behavior according to the methods developed by animal and infant psychology. It seeks to investigate reflexes and instincts, automatisms and unconscious reactions. But it has told us nothing about the reflexes that have built cathedrals, railroads, and fortresses, the instincts that have produced philosophies, poems, and legal systems, the automatisms that have resulted in the growth and decline of empires, the unconscious reactions that are splitting atoms."

In other words, behaviorism and determinism tell us nothing about our ability to create.

Hal Varian writes:

A friend of mine had brain surgery last year for a tumor. They woke him up during surgery and asked him to speak while they were cutting away at the tumor to make sure that they weren't cutting away something important. Yes, that really happened.

My friend recovered from the operation and is now doing fine.

Eric Larson writes:

I must say your paper is not very good and contains little beside conjecture. Your argument against skepticism only shows your lack of knowledge about it and/or logic. Skepticism simply states that knowledge comes from empirical observation, which along with genetic factors determines our behavior. You can choose to think of your brain as something mystical, but it is just matter and nothing more. Belief in an active god is more plausible than free will as is protectionism for that matter. Are they "necessarily" true?

It takes strong adherence to religion to ignore neurobiology and evolutionary psychology. No matter how many times you read
Atlas Shrugged it will always be just that a religion or ideology.

Barbar writes:

I strongly recommend Daniel Dennett's "Elbow Room" as an exploration of these issues. Free will and determinism are not incompatible. How could causality contradict free will -- any concept of our selves that puts us outside the causal stream of the universe is incoherent. The fact that your ability to read this paragraph is "constrained" by the laws of physics and chemistry as synapses fire in your brain does not mean that your freedom to interpret it is somehow based on limitations in the laws of physics and chemistry.

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