“Coherence Test: Does naturalism have a reason to trust reason? Testing a particular position for coherence demonstrates its level of logical consistency. Any sound worldview must contain legitimate grounds for reason and argumentation, making this question appropriate. Three arguments illustrate some extremely serious concerns:
Coherence problem A: An irrational source
According to the naturalist worldview, the source or foundation of man’s reasoning was not itself rational (endowed with reason), nor was it personal (self-aware, intelligent), and it was not teleological (purposive) in nature. Rather it was a non-rational and impersonal process without purpose consisting of a combination of genetic mutation, variation, and environmental factors (natural selection). Naturalism postulates that a combination of random chance and blind impersonal natural process (physical and chemical in nature) produced humanity’s rational faculties.
However, presuming that this kind of non-rational, chance origin lies behind human intelligence raises legitimate questions about whether human reason can then be trusted. As a matter of epistemological protocol, if not sound logical intuition, the non-rational should not be thought to produce the rational; nor the impersonal, the personal; nor the a-teleological, the teleological.
For the non-rational to cause the rational does not comport with normal everyday experience. According to the presumptions of science, an effect requires an adequate and sufficient cause, and indeed that effect cannot be greater than the cause. But in the case of evolution, the effect of human intelligence is magnitudes or exponentially greater than its supposed cause.
Even if these non-rational factors did succeed in producing the rational faculties of human beings, how can it be known that the product of this basically non-intelligent process (the human brain and mind) can and should be trusted to deliver rational content? Therefore, when one discovers that the source of human reason is not itself rational, then a valid reason has been raised to doubt and distrust the outcome of that reason. Philosopher Paul Copan describes this epistemological crisis and self-defeating dilemma: “I am relying on the very cognitive faculties whose unreliability is the conclusion of my skeptical argument. I am assuming a trustworthy reasoning process to arrive at the conclusion that I can’t trust my reasoning.”
This dilemma places the worldview of naturalism in an extremely difficult position. Naturalists are fond of asserting that they have embraced their worldview based upon purely rational factors, appealing to such things as logic and sound scientific understanding. They also often claim to have rejected theism because the problem of evil makes belief in God logically untenable.
But if the source of human cognitive faculties were not rational, then the naturalist doesn’t necessarily have a good reason to trust that he has embraced this worldview on the basis of sound rational factors. Nor is he in a position to justifiably dismiss theism based upon rational grounds. In other words, if that which produced human reasoning was not itself rational in nature, why then have any confidence in one’s present ability to reason? This consideration shows naturalism to be logically self-defeating.
Coherence Problem B: A necessary physical determinism
Many, if not most, naturalists embrace some form of materialism or physicalism. With limited ontological options, their purely natural worldview mandates that the physical universe (a matrix of matter, energy, time, and space) is the sole fundamental level of reality.
However, if naturalism involves some form of materialism or physicalism as its basic ontology (basis for being), then it follows that all actions, events, and processes are the result of purely material and/or physical forces. And if humans and their thoughts, ideas, and convictions are the result of these forces, then how can naturalism avoid some form of physical determinism that undermines such things as intention, rational deliberation, logical inference, and authentic choice? How can naturalists legitimately claim that they have embraced their worldview and rejected theism based solely upon rational considerations if fundamental physical forces have determined all things including their cognitive faculties?
Rational considerations do not fit the blind, accidental operation of the physical laws of nature. They connect with intelligence, personhood, and purposefulness.
A further difficulty can be found in the amoral implications of determinism. If physical determinism is true with respect to humanity, then human actions are neither blameworthy nor praiseworthy. A person might claim: “My molecules made me do it.”
Coherence Problem C: Survivability doesn’t guarantee objective truth
If an individual embraces naturalistic evolutionary theory, then she has to accept the idea that complex human cognitive faculties and sensory organs arose through purely accidental, blind, mindless, and purposeless processes in nature. The evolutionary process (natural selection) that is said to have taken billions of years to produce intellectual and sensory capacities in people functioned solely in light of survival value and reproductive advantage (involving such things as genetic variation and random genetic mutation).
The mechanism of evolution functioned only to enhance a particular organism’s survival changes. But evolution’s function and focus raise a serious challenge to the naturalist worldview. If evolution’s sole activity is to promote a species’ survivability, then how can people who have embraced evolutionary naturalism have confidence that their cognitive faculties provided reliable, true beliefs? In other words, if naturalism is correct, then it seems highly questionable that humans would have belief-forming faculties (mind, brain, sensory organs) that produce reliably true beliefs. Evolution’s intention doesn’t promote true beliefs, it promotes survival. And yet, a sound basis for truth is necessary if a person is to embrace a naturalistic evolution over other explanations.
Some naturalists have even suggested that human belief in such things as God, immortality, and objective moral values was produced in man as a means of promoting human survivability. So even though these ideas (e.g., God) are actually false, they somehow supported man’s ability to survive and even thrive. But this theory would mean that false beliefs may at times do more to promote human flourishing than true beliefs.
A blind source that functions on the mechanistic track of survivability alone cannot guarantee that the human cognitive system provides truth; it may even promote what is false. Survivability and truth are two very different outcomes.
Humankind’s intellectual endowments also seem to range profoundly above what could be expected from mere survivability. Humans are capable not only of arriving at truth seemingly useful in survival (for instance true knowledge of how to grow food and make weapons to kill), but also of contemplating abstractions with no apparent survival benefit (for example, thinking about beauty). If this evolutionary argument against naturalism (survivability over truth) holds logical merit, then naturalists have no sound reason (or guarantee) to trust their reason in their worldview.”
(Samples, A World of Difference)