Are we free or are our actions determined by the laws of physics? And how much free will do we really want? These questions have puzzled philosophers for millennia – and there are still no perfect answers.
But it turns out that a character from a children’s TV series may provide a clue.
Thomas the Tank Engine, despite being a steam engine, behaves like a human. Makes decisions and choices. And he is morally responsible: when he does something wrong, he is punished.
But look deeper and things get complicated. It’s an engine. His movements are determined by the shape of the rails, the operation of his engine and the railway employees. So is his free will just an illusion?
The laws of physics explain how a past event results in a future one. For example, if I put a kettle on the stove, the laws of thermodynamics dictate that it will boil at a nearby point in the future. If I don’t interfere with the kettle or the stove, there is only one possible outcome: the water will start to boil.
A strong philosophical argument against free will states that since we cannot change the past and since we cannot change the laws of physics, we cannot change the future either.
This is because the future is simply a consequence of the past and the laws of physics dictate that the past will result in the future. The future is not open to alternatives.
The same applies to us: our bodies are physical objects made of atoms and molecules governed by laws of physics. But every decision and action we take can ultimately be traced back to some initial conditions at the beginning of the universe.
We may feel like we have free will, but this is just an illusion. And the same is true for Thomas: he may appear to be free, but his actions are decided by the layout of the railway tracks and the timetable of the railway.
What he does is not open to alternatives. It is, after all, a steam engine governed by the laws of thermodynamics.
But if Thomas’s actions are not open to alternatives, why is he frowned upon when he does things wrong? If he was nothing more than a machine, would it make much sense to believe that he is morally responsible?
After all, it would be strange to say that my kettle deserves praise for boiling water, if it really could not be otherwise.
American philosopher Harry Frankfurt developed a clever thought experiment to show that the future need not be open to alternatives in order to be morally responsible.
Imagine two agents, let’s call them Killer and Controller. The controller has electrodes connected to the Killer’s brain. If Killer doesn’t do as the Controller wants, he activates the electrodes – forcing Killer to obey.
Now, the Controller really wants someone, let’s call him Victim, to die. So he thinks about directing the Killer to kill the Victim. But it turns out that the Killer actually wants the Victim to die too, so she kills the Victim without the Controller having to intervene at all. The electrodes remain closed.
What is the moral of the story? Although Killer’s actions were not open to alternatives (if she chose not to kill, the Controller would force her to do so anyway), she is still responsible and punishable as a killer.
It seems that Thomas is in the same situation: when he does things according to the rules of the railway, he is left to do them of his own accord. When he doesn’t, someone intervenes: the driver, the conductor, or the ominous Fat Controller.
But he still gets scolded when things go wrong. The fact that his actions have no alternatives doesn’t change that.
How much free will is desirable?
So how about a universe where Thomas’ future is not determined? Would he be free there?
Although we are uncomfortable with the fact that our actions can be determined, the alternative is not much better. A universe where the future is completely undefined, where it’s very open to alternatives, is just too chaotic.
I need to know that when I put the kettle on the stove, it will boil. A universe where water spontaneously turns into frozen orange juice is not a universe most of us would want to live in.
And the same goes for Thomas. If Thomas was allowed to leave the tracks, fly through the air, or if his locomotive didn’t follow the laws of thermodynamics, his universe wouldn’t work.
His character captures our intuitions about free will. We need choices and moral responsibility, but we don’t want our actions to be completely indeterminate. We want our free will to lie somewhere between complete determinism and complete randomness.
Matyáš Moravec, Gifford Postdoctoral Fellow in Philosophy, University of St Andrews
This article is republished from The Conversation under a Creative Commons license. Read the original article.