12.2 Free Will vs Determinism

Do we all have free-will? Or do we just follow and do exactly what fate expects us to do? What is free-will anyway? Many debates on free-will vs determinism boil my blood when I watch them because it is clear that the debaters use different meanings for free-will and are talking over each other.

One simple definition that people use is that free-will is the ability to do otherwise. If you decided to buy a particular car, did you really have a choice to buy a different car or is it written in your fate that you would buy that particular car? If it is, how do we even know? Would anyone in this world know? Would any non-physical entity like God know which car you are going to buy? Based on this, free-will could be defined in different ways. I will go from the strictest definition to the most lenient definition.

You have free-will if no entity, physical or nonphysical, can pre-determine what you are going to do.

You have free-will if no physical entity can theoretically pre-determine what you are going to do.

You have free-will if no physical entity can practically pre-determine what you are going to do.

You have free-will if you can do whatever you decide to do and others cannot stop you.

Do we have level 4 free-will? Most will claim we obviously do. But if we are living in an authoritarian country where we will be killed if we do things against what the ruler wants you to do, do we still have this type of free-will? Some will say that you still do because you always have the option to choose death. You still have choices. But anyway, level 4 free-will is just personal freedom for many people and shouldn’t even be considered in the free-will debate. The primary question we want to answer is whether will itself is pre-decided or not. We are not concerned over whether you can act based on your will.

Do we have level 3 free-will? When we discussed classical physics, we came across the idea of being able to predict the future of a system based on the present state of the system using physical equations. When we look at a system that is simple enough, we tend to think that its future state can be predicted. Like a box with just one ball bouncing up and down. If we know the speed of the bouncing ball and if we assume there is no friction inside the box, we could back ourselves to predict the future of the box at any time, as long as no external agent disturbs it. But we still suffer from practical difficulties. As discussed before, it is hard to make precise measurements. Add chaos theory to it, we realise that it is practically impossible to make precise predictions about the future of any objects, let alone what a human is going to do, considering the complex biological material that one is made of.

Let us ignore quantum physics for a minute and imagine a universe where only classical physics laws apply. And assume that there is no problem making measurements accurately. So, given the state of the system at one point, one can predict the future of the system as long as one has the computing power to do so. Assume that we built a machine that does exactly that. It observes the universe and then keeps predicting the future of the universe. It is called the Laplace Demon in scientific/philosophical terms.

Here lies the problem. The Laplace Demon doesn’t know who it is dealing with. You and I are Free-Will Demons. If the Laplace Demon says that I will do something, I will do the entire opposite and so will you, depending on what the Laplace Demon says about you. If the Laplace Demon says that I will eat salad today, I will eat ice-cream instead and show it to its face. If the Demon says you will just have a normal day at work, you will decide to take the day off and go to the beach. Within a day, I expect the so-called Laplace Demon to pack its bags and call it a day. To give it a send-off, we can ask it to make one last prediction about us. No matter what it says, we will use a baseball bat to destroy the Laplace Demon ourselves. Victory to the Free-Will Demons!

We assumed that the mathematical equations were correct and we could also measure everything accurately. The Laplace Demon was supposed to predict the future precisely with accurate equations and data. And we still showed how we can make the Laplace Demon wrong. How did that happen? That’s the paradox.

Even in a classical universe that is redesigned to allow us to make precise measurements, we are most definitely protected from the paradox because building something else about our universe makes it impossible to build the Laplace Demon within this universe. If the machine is going to predict the future of the universe, it should predict the future of the machine itself. If it is going to predict the future of itself, it needs the ability to store and display the future state of itself. That means more chips and memory. But It is impossible for a machine to store all this data about itself and also calculate and show all future states of itself. Imagine 3 switches which can be on or off. The switches in total have 2x2x2 = 8 possible states. The switches themselves cannot calculate their own future because all their states are required to store their current state and also to show the predicted future state. Who does the calculation then?

Thus it is impossible to make any machine that predicts its own future within the universe. Maybe it can be built outside the universe but its results should not reach the universe because in that case, the machine also becomes part of the universe and we are back to the same problem.

Putting this all together, it looks like level 3 free-will definitely exists. It is practically impossible to predict accurately what a person is going to do.

What about level-3? If quantum physics is the ultimate theory humans can ever find, then even theoretically, we couldn’t predict someone else’s actions. We could make probabilistic predictions, not precise predictions. Hence level-3 free-will also most probably exists.

What about level-4 free-will? Here things get complicated and are responsible for many religious debates. Many religions suggest that God is all-knowing. That means God knows exactly what is going to happen in our universe and that includes the actions taken by the individual. Hence, we all have a destiny. If this is the case and humans are going to do exactly what we are pre-destined to do, why are the humans morally judged later and are sent to heaven or hell? Why are humans held responsible for their actions?

Another way to look at this is to imagine a higher dimensional being that is capable of seeing the whole of our spacetime, both the future and the past. The being may know our future as long as the being never affects the universe. If it does, to predict the future of our universe would require the being to predict its own future, just like any machine in the universe that tries to predict the future of the universe. Maybe outside this physical world, the laws do allow an entity to predict its own future?

Free-will is an issue that also crops up in time-travel stories. Imagine you meet someone looking very similar to you, only a bit older. He tells you that he is you from the future. You invented a time-machine in the future. The future you came back to tell you that if you bet on a particular football team on a certain day, you can make a lot of money. If you go on and place the bet, you have changed your own fate and even the fate of the universe. That’s what most of us would assume.

What if the money you win means you never managed to create the time machine? Maybe you started drinking and gambling so much that you never got time to build that time machine? Then who really came back in time to tell you to make the bet? Some explain this using the many-worlds theory. When someone comes back in time, the universe splits into a different path. It is only in the new path that you are rich. The old path of the universe remains the same. Your future YOU disappeared from that timeline after using the time-machine.

But there are some time-travel science fiction movies and shows like Predestination and Dark which show a world that is fatalistic and predestined but still supports time travel. They call it the consistent history approach to time travel. In these stories, even with time travel, all the characters fail to change the past. In fact, they realise in really terrible ways that their decision to travel back in time was what created all their problems in the first place. In this theory, no one can predict the future of the universe from within. But because time travel usually means we are looking at the world from a higher dimension, a higher dimensional entity might.

Putting this all together, we can reasonably say that we have up to level-2 free-will. But it is hard to say whether level-1 free-will exists because we simply have no clue if non-physical entities exist.

Nature vs Nurture

There is another angle to free-will in terms of nature vs nurture. This is a common question that we deal with, when it comes to judging people. Many people consider a bad childhood or environment a reasonable justification to reduce the sentence for criminals. If someone who grew up in a rich household with great parents, their achievement is usually treated with lesser admiration than the same achievement by someone who comes from a poorer family or absent parents.

Based on science, we do agree that the environment does affect a person’s character and ability. Science also tells us that a person’s genetics plays a big role in their development. So which part of a person’s character and ability is genetic and which part is down to the surroundings? We all like to blame the surroundings when we make mistakes and claim free-will when we achieve something good. But what is really true here?

In a world of physicalism, science should solve this eventually. In a philosophy that includes non-physical entities which can affect how a person behaves, it may not be straight-forward.