The argument from reason, as my joking title suggests, insists that reason can not be reduced to physical states and that fundamentally matter must reduce to mental things and, not surprisingly, some say the origin of reason is necessarily god. Some versions don’t actually attempt to prove a god but only eliminate naturalism (which would leave an atheistic idealism) but as this argument universally asserts that naturalism can’t account for reason, and considering philosophical naturalism is a common position of atheists including myself, I felt I should explain why this too is a bad reason to believe in god or rule out naturalism.
The central idea in the argument from reason is that if our mental faculties are the result of natural processes like evolution, themselves the product of undirected deterministic physics, then what we think are reasons aren’t really reasons so rationality could not have emerged from these physical processes. In the same sense that you wouldn’t attribute “reasons” to the actions of glass breaking when dropped to the floor because it was just responding to determined physical processes, if our cognitive faculties are the result of determined physical processes we can’t truly say we are reasoning. Therefore, proponents say, if naturalism is true then we don’t have rationality and hence no reason to believe in naturalism as the position refutes itself. The alternative provided is that mental states are the fundamental substance (entity?) of reality and only if this is true can we account for rationality. As Victor Reppert states in his defense of the argument:
According to materialism, the universe begins with no mental states and somehow evolves them into existence through the shuffling and reshuffling of material particles. Suppose, however, that rationality were, so to speak, on the ground floor of reality. Suppose the universe were the result of the activities of a rational being. If that were the case, then we could understand how such a rational being could bestow beings in the universe with a measure of its rationality. - The Argument from Reason (1998)
In this case it’s easy to see where some call in god but also why this argument often stops before claiming god because some non-divine mental entities, possibly something resembling Plato’s forms, could be at the foundation of reality. However as Wikipedia (surprisingly succinctly) summarizes the portion of the argument against naturalism:
Conclusion: Therefore, human minds are not a merely physical source
- For an assertion to be capable of truth or falsehood it must come from a rational source.
- No merely physical material or combination of merely physical materials constitutes a rational source.
- Therefore, no assertion that is true or false can come from a merely physical source.
- The assertions of human minds are capable of truth or falsehood
On its face this argument seems to be claiming “I don’t know how reasoning can be a physical process, therefore it is not a physical process,” otherwise known as an argument from ignorance. There are two possible false underlying assumptions which could make up this judgement. The first is the idea that events that occur for physical reasons can’t also occur for rational reasons, or what some would call the world of ideas. This in turn is based on the extremely false idea (as opposed to a comically false idea, it’s a technical term) that all naturalists are proposing thoughts and reasons don’t exist if they reduce to physics, what would be a form of greedy reductionism. The naturalist claim that thoughts and reasons can be explained in terms of physical interactions no more means thoughts and reasons don’t exist than the idea that biology can be explained in terms of chemical reactions means biology doesn’t exist. In other words the rational source demanded to produce “assertions capable of truth of falsehood” was never in jeopardy under naturalism because thought was never claimed to be nonexistent nor independent of physics.
The second possible false assumption, disguised as a conclusion, is the idea that deterministic processes, be they physical or otherwise, can’t produce reasoning. However, as you’ll soon see, determinism is actually necessary for reasoning. A perfect reasoner will reach conclusions in a determined fashion, e.g. input A will always produce output B. Adding any indeterminacy to this process can only make the reasoning process worse. In fact if you are explicit about what a reasoning process divorced of determinism would be, the outputs (conclusions) would have to not be caused by the inputs (premises), you begin to see just how distant from any sense of reasoning it is. Moreover the entire idea of escaping the determined processes of naturalism is based on the false idea that there is some nebulous “free” option, known as libertarian free will, which is an alternative to determined and random processes and which would somehow allow our minds to operate independently of causality. However because determined and random processes exhaust all possible influences for an event, they account for all causes in and out of time and those independent of everything else, libertarian free will can’t exist.
Similarly the idea we can trust our thoughts more, or at all, if and only if there exists a mental being that created us neglects the possibility of that said being deceiving us. So the idea of appealing to god as a foundation for reason or rationality is vacuous as such a presupposition only introduces more unjustifiable fundamental assumptions needed for rationality and doesn’t eliminate the possibility of our cognitive faculties being mistaken which was the entire point of appealing to god. In totality this argument fails because where there could be genuine mystery—how did rationality come about?—it asserts impossibility based upon a misunderstanding of what naturalism implies and/or failing to realize determinism is actually exactly what is necessary for there to be rationality. Ultimately, despite the proponents who support the argument from reason, just because rationality isn’t “real magic” doesn’t mean it’s not real.