Randomness and determinism

Classical physics would seem to suggest that the world is deterministic. According to classical physics, if someone had an infinitely large memory and could perform calculations in their mind instantaneously, they would be able to predict the location of every particle at any moment in time. How? Because there is no inherent randomness in classical physics: everything, even something as seemingly random as rolling dice, can be explained and predicted with 100% accuracy using mathematical equations. Assuming that the brain and not the mind controls human decisions, this means that everything, even what human beings do, can be predicted with physics because the particles inside of a person’s brain are still subject to physical laws.

But, as it turns out, classical physics is not the only set of laws governing the universe—in recent years more and more proof has turned up for quantum mechanics. Unlike classical physics, quantum mechanics does include random factors, namely the Heisenberg Uncertainty Principle.

So, how does quantum mechanics mesh with the determinism/free will debate?

Firstly, it is obvious that the original model of determinism must be discarded. If random factors are influencing the interactions of particles, then the movements and interactions of these particles can no longer be explained with classical physics. Thus, they can no longer be predicted with any accuracy, making it obvious that determinism must be discarded. Most scientists agree with this analysis, stating that quantum mechanics suggests that the universe is probabilistic rather than deterministic. 

However, in terms of the relationship to human beings, the result remains interestingly similar to determinism. In a deterministic universe, human beings have no control over their actions, and everything they do is predetermined. Again, assuming that the brain and not the mind control a human being, even in a quantum mechanics based universe human beings still don’t have control over their bodies. Remember that in the previous case human choices were simply a product of the predetermined motions of atoms in the brain interacting with each other; now, they are the product of non-predestined atoms in the brain interacting. So even determinism no longer exists, humans still have no free will in the traditional sense.

Of course, remember that this is assuming against the existence of the mind. If human decisions cannot be explained by the interactions of the atoms in the brain and non-physical minds do exist, we would have free will anyway.