Originally written December 2007
The Impossibility of Rational Thought in a Theistic Universe
The idea of free will, as we generally conceive it, is the ability to make decisions, free from any sort of determinism, whether that be the laws of physics acting on the bits in our brains, the genetic influence of our genes on our behavior, or past events influencing the way we think and act in the future. To quote “101 Key Terms in Philosophy and Their Importance to Theology”, free will is the claim that humans have “the ability to rise above their heredity and environment and make free (i.e. uncaused) choices” (pg 31).
The concept of free will that most people embrace is explained with an idea called dualism. Dualism is the idea that humans possess a physical body, and an immaterial mind/soul. Since the mind/soul is immaterial, it is not subject to any sort of determinism, and the traditional conception of free will is therefore possible.
However, there is a huge problem with this. If our choices are the result of completely free, unrestricted, uninfluenced thought, then logic and reason do not influence our thoughts either. In contemporary philosophy of the mind, as well as cognitive neuroscience, reasons are considered to be a type of causation. But if our minds are not caused or influenced by anything (such as reasons), then we have a dilemma. Philosopher of the mind, Owen Flanagan, explains this problem quite nicely:
"Consider what it would mean to have such a free will. When I make a choice I do so ex nihilo, by electing, without anything constraining my deliberation, a course of action. But if nothing constrains my choice, then reasons don't constrain my choices either. And if that is so, then ordinary, introspection must be deemed wildly wrong. After all, it seems to most everyone that when they are deliberating among the options at hand that they are weighing pros and cons and that this information constrains the choice."
"Second, and just as bad, if when I choose I do so for no reason (choice may create a reason for action but does not itself rest on any reasons) then my choice is either arational or irrational. Since one of the main things—perhaps the main thing—any conception of free will worth wanting is supposed to do is to explain how rational choice is possible, and so to explain how I can be held rationally accountable for my choices, the orthodox conception of free will is a miserable failure. It is conceptually incoherent, in the sense that it provides no coherent way of conceiving of what it wants to gain for itself" (The Problem of the Soul, pg 124).
So as we can see, if the dualistic sense of free will exists, and our choices are not constrained or influenced by anything, then logical, rational thought is impossible. The only way for rational thought to be possible is for dualism, and its conception of free will, to be wrong. And since everyone would agree that rational and logical thinking is possible, dualism can be declared wrong.
Now here comes the kicker. For a theist to even suggest talking about anything rationally, they have to presuppose materialism! That is, the theist has to reject the idea of dualism, which is a core part of their dogma. If they don't, then they have no way to account for thinking rationally about anything in the first place.
The only way to get around this, as I can see, is for the theist to either give up the conceptions of dualism and unconstrained free will, or admit that their thinking is completely irrational or arational. And even if a theist were to admit that I am right, and their thinking is irrational or arational, they have just shown that they are wrong, since it was my reasons compelled them to change their mind.
The main thing that needs to be overcome here is for the theist to explain how exactly, something that is defined as being completely uninfluenced by anything (the soul/immaterial mind), can be influenced by reasons.
This argument also undermines the Transcendental Argument for God (logic is only accountable via Christian theism), since that argument assumes from the beginning that we can think rationally in a theistic universe. But as it turns out, we can't.
Therefore, if you can think rationally about anything, or if reasons sway your decision making, you have disproved theism.
Here is the argument in two different proofs:
1. God is an immaterial mind.
2. An immaterial mind is not influenced by anything.
3. Minds are influenced by reasons.
4. Therefore, minds are not immaterial.
5. Therefore, God does not exist.
1. Humans have minds.
2. Immaterial minds cannot be influenced by anything.
3. Human minds are influenced by reasons.
4. Therefore, humans have material minds.
The only criticism of this I can think of is for someone to say that if I am right, then this argument is not the result of rational deliberation, but the laws of physics acting on my brain.
While this may be true, it would be a genetic fallacy to assume that since my brain is a product of the laws of physics, that it cannot produce anything true. Again, I quote Owen Flanagan:
“Rational deliberation is best conceived as the process of building an overall rationale for some conclusion or course of action by blending together the relevant information in a principled manner, so as to yield a sensible conclusion or choice. Again, if we conceive of causes not as collision-like events but as algorithms or heuristics, sets of rules for dealing with information, we can see how rational deliberation is possible for complex creatures, artificial or natural” (The Problem of the Soul, pg 139).