Tuesday, May 16, 2006

Part 8: Decisions, decisions

One of the most important questions about consciousness is whether humans have free will. The simplest theory says no - we are all mindless machines, and if we get a large enough microscope and look at the human brain, we will find that the way it works is completely determined by its current state. This view is called determinism and can be summarised in the following sentence. Every event that will happen in the future is completely determined by the sum of all the events that have happened in the past. This applies to all of the choices that we make - determinism says that every decision has already been made and free will is an illusion. If we could make a big enough computer and could understand how neurons send messages, then we could create a simulation of a human brain, and that simulation would be conscious in the same way that a real human is.

The main criticism of determinism is the claim that free will is an illusion. That bothers people. In 1984, Daniel C. Dennett wrote a book entitled Elbow Room: The Varieties of Free Will Worth Wanting. Wikipedia has an excellent summary of it. In the book, Dennett argues that (1) free will is an attribute of intelligence, not consciousness, (2) there is no plausible physical explanation for how free will would work if it existed, (3) free will is an illusion, but a very useful one from the point of view of evolution, and evolution explains why humans are so defensive of the idea of free will.

(1) There is a type of incect called Sphex that feed their young by hunting other insects and bringing the prey to their nest. Before entering the nest, a Sphex drops its prey outside and inspects the next. If there is no danger, it comes out and drags the prey inside. If, however, somebody moves the prey farther away from the nest, the Sphex will find it, drag it back, leave it outside and go inspect the nest again. This can be repeated indefinitely. The insect behaves like a machine. Its brain is not complex enough to recognise the repetitive behaviour and make a different choice. It has no free will. We could define free will as the ability to avoid such futile behaviour. We humans can do it because we are more intelligent than insects. We could make the choice to break the cycle. We could even teach a computer to recognise and avoid this futile behaviour, and computers aren't conscious, are they?

(2) If we do indeed have free will, then where does it come from? The only explanation that philosophers and physicists can come up with is "quantum stuff". Everything else that we know about this world is deterministic, but in quantum mechanics we have probabilities and quantum superpositions. What if our freedom of choice comes from such superpositions, when, say, an electron is in two states simultaneously, and then it collapses into one of those states? Could that be the act of making a decision? Dennett argues that this is silly. How could we possibly have any control over which state the electron goes to? How could we call this freedom? If the electron randomly chooses a state, is that any better than making no decision at all? Would you rather all your decisions were pre-determined or random? Is there any difference?

(3) Finally, Dennett explains why we have (the illusion of) free will with the help of evolution. Free will is not the ability to make decisions; it is the ability to evaluate decisions, and that is a property of our complex brains. We can consider multiple options and choose the best one. Which one we choose is completely determined by our past experiences, but we are still able to choose. We evolved this ability because it is extremely beneficial to our survival. It is the reason that we are the most advanced beings on this planet.

Evolution also explains why we are so opposed to the idea that free will is an illusion. A species that believes it has no choice in life is likely to get depressed and apathetic, and that leads to death.

So what about responsibility? If I have no choice in any of my decisions, why should I bother making them? Why should I try to make the right one? The answer is that responsibility leads to good decisions. The reason we have laws is because they are beneficial to society as a whole. And the reason we choose not to kill or steal is because we know the consequences of those actions. The presence of responsibility affects the way in which we evaluate our decisions.

So why not give up and stop living? Nothing we do matters anyway. It is all pre-determined. Well, that is a choice you have. You have the ability to consider that choice. But realise that, as humans, we have the freedom to make the best decisions! Animals and computers and very bad at evaluating options and picking the best choices. You are much better at it. So why not take full advantage of that amazing ability?

22 Comments:

At 2:35 AM, Blogger Evgueni Naverniouk said...

It seems like when scientists, or more specifically physicists, can't explain something they just say it's part of the quantum world. And since, we don't understand the quantum world, we leave the problem be. It's pathetic. We either need to figure out what the heck quantum physics really is, or quit trying to make everything be a part of the quantum machine.

 
At 7:06 AM, Blogger Arthur said...

This comment has been removed by a blog administrator.

 
At 9:49 AM, Blogger Abednego said...

Not all scientists do that. You should read some of Daniel Dennett's books. He makes a lot of sense and doesn't cheat by using "quantum stuff".

To arthur, please don't post comments with the sole purpose of creating links to your webpage.

 
At 6:04 PM, Blogger twidjaja said...

Talking about "breaking the cycles", I think humans are not always capable of recognizing when they are doing the a stupid thing repetitively. Humans are also creatures of habits. And, of course, there is that problem of subjectivity.

By the way, if you check out http://en.wikipedia.org/wiki/Determinism, you'll see why determinism believes that there is no real randomness, and why determinists believe that quantum mechanics is deterministic.

 
At 11:18 AM, Blogger JeremyHussell said...

It seems that "free will" is another of those slippery phrases that requires a really precise definition. I first encountered this issue in high school when we read the play Oedipus Rex, which is all about people trying, and failing, to avoid prophecies.

I don't think free will and determinism are incompatible. Although the universe may be totally deterministic, we have imperfect knowledge of it (incredibly, vastly, imperfect), so we must still evaluate potential courses of action and choose among them.

 
At 12:18 PM, Blogger Abednego said...

Which definition of free will are you using when you say it is compatible with determinism? It seems a bit weak to say that, yea, we have free will, but that's because we're not smart enough to know everything. How is that different from saying we don't really have free will?

What Dennett's book argues is that it doesn't matter how much knowledge of the world we have. Free will is the ability to evaluate options and pick the best one. Given the options and the current state of your brain, you have no choice in which one you will eventually pick. It will be the best one, whatever the meaning of "best" for you is, at the moment.

The more I think about it, the harder it is to define it as anything else. It just seems obvious. How else could we possibly make decisions?

 
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At 12:52 AM, Blogger Kurt said...

I just noticed that Susan Blackmore has a blog. This entry has a bit of discussion on the matter of free will.

 
At 1:38 AM, Blogger Abednego said...

Thanks!

 
At 10:54 PM, Blogger Kurt said...

Well, while I'm at it, here is another blog entry on the subject of free will, this time from a blog on the ScienceBlogs site.

The neurological evidence seems to be pretty conclusive that there is no free will in the classical philosophical sense. But in my opinion this just means that we need to define free will in a much narrower, materialistic sense. It seems to me that a lot of hand-wringing over free will is caused by conflating the question of free will with other issues, such as determinism vs. nondeterminism.

 
At 2:19 PM, Blogger Rahul Bansal said...

Hey, thr,Nice to see your articles. I am an AI enthusiast and planning to dive into the field.

Keep posting...

 
At 10:34 PM, Blogger Harrison said...

This comment has been removed by a blog administrator.

 
At 10:36 PM, Blogger Harrison said...

I must point out that there are many AI programs capable of evaluating decisions and learning, yet they have no free will since they must follow the code.

That must be similar to what Dennet says, about how humans are totally logical and truly have no free will. However, Dennet changes position when he says free will is the ability to evaluate decisions, because then he is showing free will as a logical ability, not an attribute of consciousness as it is believed.

Ive looked into Dennet's theories and I find them quite well stated. However, some of the things I do disagree with are the ways he defines free will and consciousness.

Dennet claims that consciousness is an attribute of intelligence; the ability to be aware of its mistakes, basically said. Today we got programs that can do just that. Are they conscious?

I do not believe that consciousness is important in a practical sense. A machine can be very intelligent without being conscious, and I feel the two are independent.

 
At 10:58 PM, Blogger Abednego said...

I can see how Dennett's definition of free will can feel unsatisfactory, but I think that it's by far the best definition we have. In fact, it is the only definition of free will that we have. Every other "definition" that I have heard basically boils down to free will being "something that humans have and computers don't". That's not a definition in any reasonable sense of the word.

I also think that his evolutionary arguments make a lot of sense: evolution can explain why we feel that we have free will and are so reluctant to let go of that belief.

What do you mean by saying "consciousness is unimportant in a practical sense"? I'm afraid I have to ask what you mean by the word "consciousness" in that statement.

 
At 10:14 AM, Blogger Harrison said...

This comment has been removed by a blog administrator.

 
At 10:15 AM, Blogger Harrison said...

It isnt about satisfaction of the theory, which can be justified through claim of the nature of human behavior. However, I disagree with Dennet on some points of his theory when he tries to redefine the traits which he previously denies.

If he just said free will as we know it was just an illusion, and left it at that, all would have been well supported and logical. However, with free will and consciousness, Dennet takes an extra step and tries to define these two terms as different traits of intelligence (such as the example of the sphex). The reason this causes a problem is that many machines today can show similar humanlike behavior as what Dennet gave as example. Yet we almost certainly agree that machines do not experience consciousness or free will like we do.

The point I am trying to say is that I believe intelligence, and consciousness/free will are independent. It is possible to make an AI however intelligent, yet not experience either of the above. Therefore, Artifical Consciousness, if it is even possible, is not practically needed; since machines dont need to experience consciousness or free will to perform tasks intelligently.

Harrison
http://realai.blogspot.com

 
At 10:39 AM, Blogger Abednego said...

What do you mean by the words "experience consciousness" or "experience free will"? What is experience other than the process of receiving information and remembering it in the form of associations? Machines can do that. So I don't agree that they "almost certainly don't experience consciousness". I think experience itself is an illusion, just like free will, and in that sense, humans are just like machines.

Let me ask you this question. Do you think that it will some day be possible to understand the workings of the human body to a level that is deep enough to allow us to fully simulate a human inside a computer? In other words, are we completely physical beings, or do we have a soul? Even if we assume that there is true randomness in the world, and it is not completely predictable, will it ever be possible to create a computer program that simulates every atom in a human body in a way that makes it indistinguishable from a live human being. If so, then will that simulated human be conscious? I think this question is a very important crossroads: on one side you have science, and on the other - free will, consciousness and religion. I cannot see any middle ground. One side implies that humans are robots and the other says that we will never be able to understand how our brains work.

To address you second point, it is hard to argue that intelligence in itself is enough for machines. Clearly, we still don't have a computer program that is fun to talk to for longer than 5 minutes, yet some programs are a lot more intelligent than humans. So something still seems to be missing, and it will not be fixed by simply adding more intelligence.

 
At 11:14 PM, Blogger Harrison said...

I feel that until further evidence turns up, the idea that free will, consciousness, and experience is an illusion is a very logical explanation. It perfectly explains the question of what makes humans different from intelligent machines: nothing.

However, I must disagree on your generalization of viewpoints being religious. Many theories today borrow from theorized concepts, supposed but impossible to see. One such example is quantum theory. It is not that there is no evidence to suggest it, but that it would be difficult or impossible to prove. Unless logically disproven or the lack of basis made apparent, that theory cannot be dismissed as simply 'religious'.

If you would allow me to get off topic for a moment here, it really depends on what you define as religious. I know some professors on this campus who believe in Intelligent Design and work in scientific associations which try to prove it through use of current evidence or experiments. These two people are both qualified scientists in their field, and are very logical. They recognize evolution as a well supported theory, but they also are aware of the weaknesses in evolution. They are very logical, are not part of any religion, and borrow nothing other than evidence and principles of science.

 
At 11:26 PM, Blogger Harrison said...

They do not believe in the Christian god nor the Muslim god but just in the theory that something created earth. It could be aliens, or a supernatural being... and to support it they use theories such as irriducible complexity and the biological threshold. They might be wrong. They may be proven wrong. But their theory is stated and supported.

And in contradiction to what you have said, I find that you are trying to have faith in what cannot be percieved. From what you have said in your articles, I think we can agree that intelligence is the ability to perform effective actions consistent with the purpose of the entity. However, you are stating that intelligence is not enough. Sure I realize that today the best chatbots, for one example, are exceedingly unintelligent and dont even speak consistently with themselves. However, there is no basis to support your statement that we need something more than intelligence. For all we know we havent reached the limit of what programming is capable of doing. Hoping for a practical breakthrough by having a machine attain the disputed attributes of consciousness/free will is more of a 'gut feeling' than a logical statement deriving from what we already know.

I simply feel that whatever free will or consciousness is, we do not need it. Anything as intelligent as possible can be made just through logical commands of programming without need for the unseen.

Harrison

 
At 11:44 PM, Blogger Abednego said...

The way I understand religion, is that it is based on the assumption of faith. There is a fundamental belief in god, or reincarnation, or a soul, upon which the rest is built. Science says that's wrong. Nothing is the absolute truth, and everything needs to be tested and verified.

Your example of the scientists who are trying to find evidence for intelligent design is fine. As long as they don't accept intelligent design as a truth, they are doing science. In the same way, accepting evolution as the absolute truth is wrong, too. It could be a wrong theory. It probably isn't though. The point is to keep looking, testing and experimenting.

 
At 5:54 AM, Blogger James said...

I just like to answer your questions Abednego:

>Do you think that it will some day be possible to understand the workings of the human body to a level that is deep enough to allow us to fully simulate a human inside a computer?
Yes, but it won't be anytime soon! (if ever)


> In other words, are we completely physical beings, or do we have a soul?
I'm 100% physical. I really never understood this concept of soul. I know I don't have one. I know you won't find one.


I don't know why some people are afraid to be a machine. Being a machine doesn't changes the fact that we can love, care and share emotions.

I think that the problem is that they have a poor concept of what a machine is. They probably look at their toaster and think "No way, I'm not your brother!"
:-)

 

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