Do Paul Moser and C. Stephen Evans's "Natural Belief Argument" succeed in establishing probabilistic support for theism, or does it fall into the evolutionary bias fallacy?

At the heart of contemporary analytic philosophy of religion, the "Natural Belief Argument" emerges as an attempt to establish probabilistic support for theism by pointing to the natural human inclination toward belief. Paul Moser and C. Stephen Evans are among the most prominent developers of this argument in recent decades, but the debate surrounding it reveals deep tensions between theistic and naturalistic explanations of human cognitive phenomena.

Inadequate Responses to Avoid

From some theism defenders:

"The existence of natural inclination toward belief proves God's existence." An unjustified logical leap. Even Moser and Evans themselves are careful in their formulations: they speak of "probabilistic support" rather than conclusive proof. The transition from "humans naturally tend toward X" to "X is true" requires additional complex premises.

"All evolutionary explanations of religion are reductionist fallacies." Unjustified wholesale rejection. Contemporary evolutionary explanations (Boyer, Atran, Barrett) are sophisticated and supported by extensive empirical research. Rejecting them wholesale without engaging with their details weakens rather than strengthens the theistic position.

"Calvin's sensus divinitatis settles the matter." Confusion between philosophical traditions. Moser and Evans work within a different framework from Plantinga's Reformed epistemology. Their arguments do not depend on assuming the existence of a special cognitive faculty for God, but on analyzing general cognitive inclinations.

From some naturalists:

"Evolutionary psychology has completely explained religion, case closed." Exaggerated claim. Even leading researchers in the evolutionary psychology of religion (Barrett, McCauley) acknowledge that their explanations account for mechanisms rather than truth or falsehood. Functional explanation of a phenomenon does not determine its truth value.

"Any argument from human nature is a naturalistic fallacy." Misapplication of the naturalistic fallacy concept. Moser and Evans do not claim that "what is natural is necessarily correct," but rather present a complex epistemological argument about the default reliability of basic cognitive inclinations.

"Evolutionary bias invalidates every argument from nature (fiṭra)." Excessive generalization. The question of when evolutionary explanation constitutes a "debunking explanation" and when it does not is a subtle philosophical matter requiring case-by-case analysis.

Why These Responses Are Inadequate

They fail to grasp the real complexity of contemporary debate about the relationship between evolutionary explanations and cognitive claims. The question is not "Does religion have an evolutionary explanation?" but "What is the cognitive significance of having an evolutionary explanation?" This is a much deeper question.

Structure of Moser's Argument

Paul Moser in "The Evidence for God" (2010) and "The Severity of God" (2013) develops an argument distinct from traditional arguments:

First: Humans possess a "fundamental cognitive inclination" toward seeking transcendent meaning, absolute value, and relationship with what transcends the material. This inclination is cross-cultural and historically constant.

Second: This inclination differs qualitatively from purely adaptive inclinations. While fear of snakes or inclination toward sweet food can be easily explained evolutionarily, the inclination toward the transcendent exceeds direct adaptive benefit and may sometimes oppose it (sacrifice, asceticism, contemplation).

Third: The best explanation for this inclination is the existence of a transcendent reality to which our cognitive nature responds. Just as our inclination to perceive material objects is best explained by the existence of a material world, our inclination toward the transcendent is best explained by the existence of transcendent reality.

Fourth: Alternative explanations (evolutionary illusion, psychological projection) face the problem of "self-undermining": if our basic cognitive inclinations are unreliable, this undermines confidence in the very reason we use to reach this conclusion.

Evans's Complementary Formulation

C. Stephen Evans in "Natural Signs and Knowledge of God" (2010) adds a semiotic dimension:

Natural religious inclinations function as "natural signs" pointing to God. These signs do not logically compel but cognitively direct. Like smoke pointing to fire without being conclusive proof of it, religious inclinations point to God without logical compulsion.

Evans distinguishes between three types of natural signs:
1. The sense of cosmic dependence
2. Moral awareness of absolute responsibility
3. Longing for perfection and existential fulfillment

Each sign works independently but they combine to form a "cumulative case" for theism.

The Challenge from Evolutionary Bias

The strongest criticism comes from the "Evolutionary Debunking Argument":

Pascal Boyer in "Religion Explained" (2001) and Scott Atran in "In Gods We Trust" (2002) present a sophisticated evolutionary explanation: religious inclination is a by-product of cognitive mechanisms that evolved for other purposes:

- Agency detection mechanism: evolved to detect predators, but produces "false positives" seeing agency where none exists.
- Promiscuous teleology: the inclination to see purpose and intention in natural phenomena.
- Dualistic thinking: the natural separation between body and mind/soul.

These mechanisms together produce religious inclination without need for actual religious reality.

Justin Barrett in "Born Believers" (2012) adds: even children show religious inclinations before cultural indoctrination, supporting the biological evolutionary basis.

The Theistic Response to the Evolutionary Challenge

Moser and Evans develop several lines of defense:

First: "Compatibility Argument": the existence of an evolutionary mechanism does not negate content truth. Just as our mathematical ability has an evolutionary basis but this does not make mathematics illusory, so with religious perception.

Second: "Divine Guidance of Evolution Argument": evolution itself could be the mechanism God used to implant religious inclination. Evolutionary and theistic explanations are not necessarily contradictory.

Third: "Over-explanation Problem": evolutionary explanations explain general inclination but fail to explain the diversity and special depth of religious experience among mystics and saints.

Fourth: "Selective Reliability Argument": why trust cognitive mechanisms in science and doubt them in religion? If evolution produces unreliable mechanisms in one domain, doubt should extend to all domains.

Critique of Evolutionary Analysis Itself

Leon Turner in "Evolutionary Psychology of Religion" (2021) points to problems in evolutionary explanation itself:

- Lack of consensus on the precise evolutionary mechanism for religion
- Difficulty explaining religion's persistence despite sometimes high evolutionary cost
- Vast diversity in religious forms challenges reductionist explanations

Connor Wood in "Ritual and Religion" (2022) adds: current evolutionary explanations account for some aspects of religion but fail to explain the most complex and abstract aspects.

Contemporary Assessment

Helen De Cruz in "Religious Disagreement" (2019) provides a balanced assessment: evolutionary explanations do not necessarily constitute "debunking" of religious beliefs. It depends on:

1. Whether the evolutionary mechanism is truth-tracking or not?
2. Whether there is a causal relationship between religious truth (if it exists) and the evolutionary mechanism?
3. How independent are other reasons for belief from the evolutionary mechanism?

From the Perspective of Rational Weighing (rajḥān ʿaqlī)

The Natural Belief Argument by Moser and Evans provides modest probabilistic support for theism, but does not settle the matter. Strengths:

- Wide recognition of the universality of religious inclination
- Difficulty of reductionist explanations in accommodating all dimensions of the phenomenon
- Coherence with other arguments in a cumulative framework

Weaknesses:

- Possibility of reasonable naturalistic explanations
- Unclear causal relationship between inclination and truth
- Religious diversity complicates inference to a single truth

Most probable position: The argument contributes to the probabilistic balance but needs to combine with other arguments. Evolutionary explanation does not completely invalidate it but weakens its independent inferential force.

Where We Stand in This Debate Today

The debate over the Natural Belief Argument has seen notable developments between 2020 and 2026. In cognitive science of religion, new empirical studies (Baimel et al., 2021; Banerjee & Bloom, 2023) have shown that religious inclinations are more complex than early evolutionary models assumed, involving cognitive, cultural, and environmental factors that cannot be reduced to a single mechanism like hyperactive agency detection. Conversely, evolutionary debunking arguments (Wilkins & Griffiths, 2023) have become more precise, distinguishing between types of cognitive inclinations and degrees of reliability by domain.

On the theistic side, new formulations have emerged integrating the Natural Belief Argument with philosophy of mind and theories of consciousness (Arcadi & Turner, 2022), transcending the old dichotomy between "evolutionary explanation or divine explanation." The "explanatory pluralism" approach has also gained momentum: evolutionary and theistic explanations operate at different levels of analysis and do not necessarily compete.

The philosophically sound position today: the Natural Belief Argument does not fall to the evolutionary challenge, but neither does it stand alone. Its real strength emerges when integrated within broader cumulative argumentation—precisely what the cumulative rational weighing method adopted by this site requires.

For Reading

- Paul Moser, The Evidence for God (Cambridge UP, 2010)
- C. Stephen Evans, Natural Signs and Knowledge of God (Oxford UP, 2010)
- Pascal Boyer, Religion Explained (Basic Books, 2001)
- Justin Barrett, Born Believers (Free Press, 2012)
- Helen De Cruz, Religious Disagreement