Thursday, February 11, 2016

The dilemma determinism versus freedom

In one of my mystery novels (El Zahir de Quetzalcoatl) the protagonist must solve three riddles, as in the classic fairy tales. The third puzzle consists of three statements that cannot all be true or false. This enigma is what you might call a trilemma.
A famous trilemma (usually called the 3-L) was formulated by C.S.Lewis to justify the divinity of Christ. Assuming that Christ affirmed his own divinity, Lewis posed the following alternatives: either Christ was a Lunatic, or a Liar, or he was the Lord. Of these three statements, only one can be true, as each one excludes the other two.
On the question of human freedom, whose reality is denied by deterministic philosophy, Brigitte Falkenburg proposes another trilemma, a little different, because in this case any two of the three alternatives can be true, but then the third must be false. This is her trilemma:

  1. Physical causality is closed. In other words, physics is deterministic. Every physical phenomenon has been caused by other physical phenomena.
  2. Mental phenomena are different from physical phenomena. In other words, the mind is not controlled by physical phenomena. In a previous post I mentioned the four different answers given by philosophers to the mind problem. This assertion would correspond to the dualist approach, or perhaps to emergent monism.
  3. We can cause physical phenomena with our minds. That is, final causality is possible. Our intentions (mental phenomena) can have physical consequences (such as pressing a button).
Thinking a bit on these three alternatives, it is evident that all three cannot be true at the same time:
         If 1 and 2 are true, 3 must be false, for if mental phenomena are not physical, and only physical phenomena can cause physical phenomena (physical causality is closed), it follows that the mind cannot cause physical phenomena.
         If 1 and 3 are true, 2 must be false, because if the mind can cause physical phenomena, and only physical phenomena can do that, it follows that the mind must be a physical phenomenon, therefore statement 2 is false.
         If 2 and 3 are true, 1 must be false, because if the mind is not a physical phenomenon and it can produce physical effects, it follows that physical phenomena are not alone producing those effects, i.e. physical causality is not closed.
In conclusion, at least one of the three statements in the trilemma must be false. Which one?
         If 2 and 3 are true and 1 is false, humans are free, because freedom means to be able to make decisions about future actions, and those decisions must arise from a mental deliberation not fully determined by our previous brain states.
         However, if 1 is true, humans would not be free, because our decisions would be completely determined by our previous brain state.
Statements 2 and 3 have been part of the common consensus of mankind throughout most of the history of thought. They started being questioned in the seventeenth century, with the beginning of materialist philosophy.
Ilya Prigogine
Throughout the twentieth century, statement 1 has become very questionable. Discoveries like the uncertainty principle (which makes it possible that there are events without a cause, provided they are below the limits set by the principle), or the thermodynamics of processes far from equilibrium (Ilya Prigogine), which describes dissipative systems by means of bifurcation diagrams where the path followed by the system is not predictable, together with the fact that biological systems (including the human brain) are precisely this kind of systems, make statement 1 much less reasonable today than it appeared to be during the nineteenth century.
Therefore we can say that the dilemma between determinism and freedom, which began over three hundred years ago (between Descartes and Hobbes) and has continued until today, now appears to lean to the side of freedom.
And yet, many neuroscientists and writers of popular articles talk as though the problem is already solved in favor of determinism. Observe, for example, these words by Francisco Rubia:
Is free will an illusion...? That is exactly what neuroscience argues, that this conception of freedom is incompatible with determinism, with the deterministic laws that govern the universe... Physicists tell us that the whole universe is subject to the deterministic laws of nature, so it would be strange that human beings, their brain/mind, were not. (El fantasma de la libertad, 2011).
Faced with this display of dogmatism (Soler Gil says that it looks as if some neuroscientists have studied physics in nineteenth century textbooks), we can pose a new dilemma: Do they really know nothing about modern physics? Or perhaps they reject it because it goes against their deterministic ideology?
Finally, I want to defy materialist philosophers with a question previously posed in another post in this blog (adapted from Sheldrake, 2012):
Materialism affirms that we are not free, that we are programmed machines, that whenever we act or think, we have no option but to act or think as we actually act or thinkAre you a materialist because you have meditated and found reasons for this position, or because you have been programmed to accept it?

The same post in Spanish
Thematic thread on Natural and Artificial Intelligence: Preceding Next
Manuel Alfonseca

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