A student of mine is writing his bachelor thesis on “free will, quantum mechanics and the system of justice”. I’m very happy about that, because it gives me an excuse to dive into matters I’ve been interested in since childhood. I want to use this blogpost as a noteblock on which I roughly sketch my thoughts on these matters. Sometimes the attempt to write down a coherent story about your point of view shows you that there are gaps in your argumentation you hadn’t expected.
Do the theories of physics rule out the possibility of human free will? It is a popular thought that there is no room for free will in classical physics while in quantum mechanics there is room for free will (because of the uncertainty principle). It is very important that there is free will, so the popular story continues, because our system of justice presupposes the possibility of human choice – How else could a thief be held accountable for a misdeed?
As with any philosophical discussion, we need to be very clear on what we are talking about, so let’s start with some concepts:
I have a physicalist view of the human mind, in which consciousness emerges from the workings of the brain, and nothing else. So in my view ‘will’ is just matter (particles and energy) moving about in certain ways.
The word ‘free’ expresses a relation. The question whether something is free without further context has no meaning and therefore cannot be answered. Free is always understood as free with regard to something else. For example, something can be free in the context of a certain set of laws.
Using these definitions, we see that the question “does free will exists?” is incomplete. The question should be replaced by other questions:
- Is the human will free with respect to the laws of physics?
- Is the human will free with respect to the laws of criminal justice?
Question 1: Too early to tell
The first question, “Is the human will free with respect to the laws of physics?”, has a strange form. What are the laws of physics? Regardless of philosophical standpoints, the laws of physics describe what is going on on. Our will is one of the things that are going on, so the question whether our will can be free with respect to the laws of physics is circular: for our will to change the laws of physics would have to be different.
So, where are we? Is the human will free with respect to the laws of physics? No, it isn’t: the laws of physics are our will – but perhaps there is some other set of laws with respect to which the human will is free.
What the definitions tell us is that if the human will is completely described by physics it can not be free from the laws of physics. Whether perhaps there is an aspect of the human mind which is not described by current physics is a different question, which the future of scientific research will answer (what comes to mind is that Einstein himself did not believe that quantum theory is a final and complete description of reality).
I will explore the second question in my next blog post. Can our system of justice function if we have no free will with respect to the laws of physics?
“The laws of physics do not dictate our will; the laws of physics are our will”Tweet