Tag Archives: Free will

Free will and punishment

On several occasions we have published posts about criminal law on this blog. In general our position is that only acts which cause harm on non-consenting others should be prohibited, and should be punishable by law. What constitutes harm is subject to debate. However in this post we want to discuss another topic: whether the existence or non-existence of a free will is relevant in matters of criminal law.

Some authors have argued that if humans do not posses a free will, they cannot be held responsible for their actions and therefore society has no right to punish them. Some people have used the reverse reasoning to defend the existence of a free will: if people have to be held accountable for their actions, they should posses a free will; therefore a free will must exist. This latter argument is a fallacy, the so-called moralistic fallacy or the idea that the existence of A can be established from the moral desirability of A.

The most important argument raised against the existence of a free will is determinism. This is the ontological position that the order of events in the universe has been predetermined and consequently cannot be changed. There are many different types of determinism, but currently the most important one is the determinism of Laplace or Laplacian determinism. French scientist Laplace deduced from Newtonian physics that the universe should be deterministic at the end of the 18th century.

Central to Newtonian physics is the concept of force: a particle on which no forces are acting will either remain in rest or move in a straight line at a constant speed. In order to accelerate or decelerate, or to change its direction, you need to apply a force on it. The change in velocity and direction of the particle, is dependent on the magnitude and direction of the force acting on the particle. Laplace made the conclusion that if you would know the location of all particles in the universe and all forces acting on them at a given moment in time, and you know all laws of physics, you would be able to calculate the configuration of particles and forces at any other point in time.

Laplace’s determinism is based on the idea of a causal chain: cause and effect. Though Newtonian physics has been replaced by relativistic physics, determinism was still strongly established. After all, Einstein’s theory of relativity is no less deterministic than Newton’s theory. Even though many, if not most, physicists believe that quantum mechanics is probabilistic rather than deterministic, there are still many scientists who support deterministic versions of quantum theory.

Even if we, for the sake of the argument, assume that quantum mechanics is probabilistic and that random quantum fluctuations are capable of steering the human mind; the existence of a free will is still not proven. After all, we have no influence on the occurrence of these fluctuations and consequently we do not control their effects. Suppose that the human brain depends on a single quantum event: the spin of a particular hydrogen atom somewhere in our nerve system. The spin is either “up” or “down”, each with equal probability. If the spin is “up” the brain will choose action A, but if the spin is “down” it will choose action B. Since the spin of a hydrogen cannot be controlled by the brain, we cannot strictly speak of “a free will”.

We can conclude that a strong case can be made against the existence of a free will. So the question is now whether the non-existence of a free will matters in case of moral issues such as crime and punishment. I will argue it does not matter at all. Let we consider the following analogy: a game of pool. If a ball lies on a pool table, while no forces are acting on it, the ball will remain where it is. If a player pushes another ball with his cue stick. the second ball will follow a trajectory which is determined by the initial force (from the player) and friction. However when the second ball collides with the first one, the trajectory of the ball will be changed and also the first ball will move. But if the payer had not pushed the second ball, the first ball would have remained in rest.

Determinism is often misunderstood as that outcomes cannot be changed. But in fact, at least in Laplacian determinism, determinism only says that if you know the input, you also know the output: if you know that x+y=z, once you know both x and y, you automatically know z. However if don’t x, y or both, you cannot know z.

We can model the human mind as a function f of y and y: f(x,y)=z. Here are x and y what we can call external variables, and z is the internal state of the human mind. Now for every pair of x and y, there is one value of z; which makes this model a deterministic model of the mind. By changing x and/or y, we can control the state of the mind.

Even we do not have a free will, we can still suffer. Regardless of the (non)-existence of a free will, the reduction or elimination of harm is a good thing to do. By prohibiting harmful action and imposing penalties on such actions, we might reduce harm. How can this work?

First, punishment might act as a deterrent: the imposing of penalties might act as external variable which changes the state of mind z such that the person affected will not commit a crime. Even if the deterrence function of penalties only reduces the amount of crimes committed, it would be a good result. Secondly, punishment might change the way the criminal thinks: either the experience of punishment is such an unpleasant one, that he does not want to experience it again, or as result of punishment the criminal’s “mind function” is transformed from f(x,y) into g(x,y). Also in this case it would a good result, if crime is only reduced by some amount. Thirdly, punishment might remove a criminal from society (either by imprisonment or death), so he cannot commit any further crime.

None of these functions of punishment do require the existence of a free will. In fact the contrary is true, to some degree. In order for these function to work there should be some determinacy in the relation between punishments and criminal behaviour.