The Moral Argument
1. Everyday Moral Intuitions
Most of us recognize that it is wrong to inflict harm on others for mere pleasure. But why?
Is it merely because we fear retaliation?
If we possessed absolute power and faced no threat of reprisal, would it then be permissible to harm others for amusement? No.
Is it simply because we possess intelligence (unlike other animals)?
We can imagine highly intelligent extraterrestrial beings who derive pleasure from killing humans. Would such actions be morally acceptable for them? No.
History demonstrates that many intelligent people have inflicted harm on others for pleasure.
We refrain from such actions not merely from prudence, but because we recognize them as morally wrong.
Is it morally good that parents love their children? Yes.
Consider a poster from a university Sexual Assault and Information Center: "Sexual Assault: No One Has the Right to Abuse a Child, Woman, or Man." Most recognize that sexually abusing another person is wrong—not merely socially unacceptable, but genuinely morally wrong.
Similarly, the Holocaust was objectively wrong even though the perpetrators believed it justified, and would remain wrong even if the Nazis had won World War II and convinced everyone otherwise.
The question then arises: Do we possess genuine knowledge that some things are objectively right or wrong? The answer appears to be yes.
Working definitions:
Right = morally good (we ought to do it)
Wrong = morally bad (we ought not to do it)
2. Moral Nihilism Challenge
What if someone claims: "Nothing is objectively right or wrong!"
Most people continue to respond as if some things genuinely are right or wrong—particularly when they experience injustice or are wronged by others (e.g., Story of the Blue Folder).
Even if someone sincerely maintains that nothing is objectively right or wrong:
This resembles a blind person who denies the existence of physical objects.
Such a belief does not overturn our knowledge that physical objects (and objective moral distinctions) exist.
3. Formulations of the Moral Argument
Let OMVD = Objective Moral Values and Duties.
Standard form:
If God does not exist, then OMVD do not exist.
OMVD do exist.
Therefore, God exists.
Logically equivalent contrapositive form:
If OMVD exist, then God exists. (Contrapositive of premise 1 above)
OMVD do exist.
Therefore, God exists.
Both formulations are logically valid. Premise 2 is defended through moral experience and intuition; premise 1 through considerations of ontological grounding and explanatory adequacy.
Important note: This argument's persuasive force depends on accepting premise 2—that objective moral values and duties actually exist. For those who genuinely deny the existence of objective morality (moral nihilists or thoroughgoing moral relativists), this argument will not be compelling. The argument is most effective for those who already recognize, through moral experience, that at least some things are objectively right or wrong, but who may not have considered what best explains or grounds this moral reality.
4. Logic Refresher
The moral argument uses a valid logical form. Here are the two ways to present it:
Standard Form (Modus Ponens)
This is the form typically used by apologists like William Lane Craig:
Contrapositive Form
The contrapositive is logically equivalent to the standard form and may be clearer for some readers:
Both forms are valid. The contrapositive simply reverses and negates the conditional statement—if "not A implies not B" is true, then "B implies A" must also be true.
What We Are NOT Doing: Affirming the Consequent (Fallacy)
The moral argument should not be confused with this invalid form:
This is a fallacy called "affirming the consequent." Here's why it doesn't work:
Cat/Mammal Example:
The moral argument avoids this fallacy by starting with the correct conditional: "If God does NOT exist, then OMVD do NOT exist" (or its contrapositive).
5. Key Moral Concepts
Moral value: The intrinsic worth, goodness, or badness of a person, character trait, or action.
Moral duty: Our obligation to act rightly, independent of our preferences or desires.
Example: It may be admirable to become a physician, but this is not typically a moral duty. Similarly, becoming a farmer or diplomat would be good, but one is not morally obligated to pursue any particular career path.
Not all good options constitute moral duties. Sometimes only bad choices exist (consider Sophie's dilemma in Sophie's Choice), yet choosing isn't morally wrong since one must choose.
Objective moral values: Moral truths that hold independently of whether anyone believes them or not.
Example: The Nazi persecution of Jews was morally wrong even if the perpetrators sincerely believed it justified and even if they had successfully silenced all opposition. The Holocaust was objectively wrong even though Nazis believed it right, and would remain wrong even if the Nazis had won and convinced everyone otherwise.
6. Premise 1: If God Does Not Exist, OMVD Do Not Exist
6.1 Clarifying the Argument
An important distinction must be emphasized: This argument concerns God's existence as necessary for objective morality, not belief in God. Three questions must be carefully distinguished:
Must we believe in God to live moral lives? No—nonbelievers clearly can live good, decent lives.
Can we recognize objective moral values without believing in God? Yes—one needn't believe in God to recognize we should love our children.
Can we formulate ethics without referring to God? Yes—nonbelievers recognizing human intrinsic value can develop ethical codes (though excluding obligations toward God).
The actual question is: If God does not exist, do objective moral values and duties exist? This concerns ontological grounding, not epistemology or moral behavior.
This confusion between belief in God and God's existence is illustrated in a debate between William Lane Craig and humanist philosopher Paul Kurtz. When Craig argued that without God, no objective moral values, duties, or accountability exist, Kurtz responded:
This response demonstrates the common misunderstanding, as it only shows belief in God isn't essential to living morally, not that God's existence is unnecessary for objective morality.
6.2 The Naturalistic Challenge
Critical questions for a naturalistic foundation of morality:
What provides the ontological foundation for moral values?
What grounds the intrinsic value and dignity of human beings?
Why should humans be considered morally significant on naturalism?
What imposes moral obligations (duties) upon us?
Naturalism—the view that only entities describable by natural science exist—appears to be morally neutral. Scientific instruments do not detect moral properties. Under strict naturalism, moral values risk being mere illusions or useful fictions.
Objective Moral Values Require God
Naturalism explains moral values as evolutionary byproducts and social conditioning. Just as baboons exhibit cooperative behavior because natural selection favored survival advantages, humans display similar patterns for identical reasons. Sociobiological pressures produced a "herd morality" that aids species perpetuation. But nothing makes this morality objectively true. Rewinding human evolution and restarting might produce entirely different moral systems.
As Darwin himself wrote in The Descent of Man,
Considering humans special and our morality objectively true constitutes speciesism—unjustified bias toward one's own species. Without God, no basis exists for regarding human-evolved morality as objectively true. Remove God, and one is left with an apelike creature on cosmic dust harboring delusions of moral grandeur.
Objective Moral Duties Require God
Consider an analogy: Non-human animals lack moral obligations to one another. When a lion kills a zebra, it kills but does not murder. When a great white shark forcibly copulates, it does not commit rape in any moral sense—these behaviors fall outside the categories of moral prohibition or obligation. If humans are merely sophisticated animals, what accounts for our status as moral agents?
Actions like incest and rape may be biologically and socially disadvantageous, becoming taboo through human development. But this doesn't demonstrate they're genuinely wrong. Such behavior pervades the animal kingdom. Without a moral lawgiver, violating herd morality would be no more serious than belching at dinner—merely unfashionable, not morally wrong.
7. Atheistic Moral Realism (AMR)
Central claim: Objective moral values and duties exist independently of God as ungrounded brute facts.
This view—sometimes called atheistic moral platonism—holds that moral values like justice, mercy, and love exist without foundation in God, similar to how Plato thought the Good exists independently as a self-existent Idea. Later Christian thinkers equated Plato's Good with God's moral nature, but Plato conceived the Good as existing alone.
Contemporary defenders of theistic grounding include eminent philosophers Robert Adams, William Alston, and Philip Quinn. Yet atheistic responses often ignore this sophisticated work. For example, the article on God and morality in the Cambridge Companion to Atheism (2007) refers neither to these scholars nor to their solutions, but attacks only the view that God arbitrarily made up moral values—a straw man that virtually nobody defends.
Philosophical difficulties:
Explanatory opacity: What does it mean for a value like justice to simply exist as a brute fact? It's easy to understand what it means for a person to be just, but bewildering when someone says justice itself exists absent any people. Moral values appear to be properties of persons; understanding how justice exists as an abstraction is difficult. This view posits an ontologically mysterious moral realm with no further grounding or explanation.
The problem of obligation: Even granting that values like mercy, justice, love, and forbearance exist as abstract entities, how do they generate binding obligations for moral agents? Who or what imposes a duty to be merciful? On this view, moral vices like greed, hatred, and selfishness also presumably exist as abstractions. So why are we obligated to align with one set of abstractly existing objects rather than another? Atheistic moral platonism, lacking a moral lawgiver, has no grounds for moral obligation.
Evolutionary coincidence: It appears remarkably fortuitous that undirected evolutionary processes would produce creatures whose moral faculties reliably track an abstract, ungrounded moral realm—as if the moral realm somehow anticipated our arrival. It's far more plausible that both natural and moral realms exist under God's authority, who gave us both natural laws and moral law, than that these independent realms coincidentally meshed.
7.1 The Reductive Naturalist Strategy
Some atheists propose that moral facts are simply natural facts (analogous to mathematical truths like 2 + 2 = 4).
Central question: Can moral facts be reduced to purely descriptive natural facts?
Example: The natural fact that I will strike a dog if I fail to brake provides me with a reason to brake—yet the normative force (the "ought") is not identical to the descriptive fact itself.
Moral facts function as normative reasons—considerations that count in favor of certain beliefs, actions, or desires. They resist reduction to mere descriptions of what is the case.
7.2 The Problem of Moral Accountability
Even granting the existence of abstract or concrete OMVD under naturalism, without God there remains no ultimate moral accountability. If death terminates all conscious existence, it makes no ultimate difference whether one lives as Stalin or as Mother Teresa.
8. Humanism: Human Flourishing as the Standard
The humanist proposal: Whatever contributes to human flourishing is good; whatever detracts from it is bad—this is taken as a brute fact. Humanity replaces God as the moral anchor; duties derive from what promotes human flourishing.
Philosophical objections:
Arbitrariness: Why privilege human flourishing over, say, ant or mouse flourishing within an atheistic framework? Why is harming another human being wrong beyond mere species preference? When challenged to explain why harming humans would be wrong under atheism, Dartmouth ethicist Walter Sinnott-Armstrong responded, "It simply is. Objectively. Don't you agree?"[3] While this may be true, it doesn't answer the question of what grounds this objectivity given an atheistic worldview. Selecting human flourishing as morally special appears arbitrary without a theistic foundation.
Explanatory deficit: Like atheistic moral realism, humanism asserts that moral properties (goodness, badness) somehow "attach" to states of affairs without providing a satisfying ontological or explanatory account of how this occurs. For example, atheists sometimes claim that badness necessarily attaches to wife-beating, and goodness necessarily attaches to a mother nursing her infant. Once all natural properties are in place, moral properties necessarily accompany them. Given atheism, this seems extraordinarily implausible. Why think these strange, nonnatural moral properties like "goodness" and "badness" even exist, much less necessarily attach to various natural states?
The "shopping list" approach: Humanistic philosophers have taken a "shopping list" approach to ethics. Because they hold humanism, they simply help themselves to needed moral properties without explanation. What's needed is some account for why moral properties attach to certain natural states. It's inadequate to assert that humans have intrinsic moral value—that's not disputed (indeed, that's premise 2 of the moral argument). What's needed is some reason to think humans would be morally significant if atheism were true.
God as the Natural Stopping Point
By contrast, God is a natural stopping point as a foundation for objective moral values and duties. Unless we're moral nihilists, we must recognize some stopping point, and God as ultimate reality is the natural place to stop. Moreover:
God is by definition worthy of worship, so He must embody perfect moral goodness.
God, by definition, is the greatest conceivable being, and a being that grounds and sources goodness is greater than one merely sharing in goodness.
So theism isn't characterized by the arbitrariness and implausibility afflicting humanism.
9. The Euthyphro Dilemma
Classic formulation:
Is something good because God wills it? (If so, then goodness appears arbitrary.)
Does God will it because it is good? (If so, then goodness exists independently of God.)
The theistic response: This dilemma presents a false choice. A third alternative exists: God wills something because He is good. God's own perfectly good and holy nature supplies the absolute standard for moral value. God is the locus and source of moral value by nature—loving, generous, just, faithful, and kind. This provides a necessary, non-arbitrary foundation—a "brute fact" only in the sense of being the ultimate explanatory terminus.
More precisely:
Moral values aren't independent of God because God's character defines goodness. God is essentially compassionate, fair, kind, impartial, etc. His nature is the moral standard defining good and bad.
His commands necessarily reflect His moral nature, so they're not arbitrary.
The morally good/bad is determined by God's nature, and the morally right/wrong is determined by His will.
God wills something because He is good, and something is right because God wills it.
When atheists ask, "If God commanded child abuse, would we be obligated to abuse children?" they're asking something logically incoherent—like asking "If there were a square circle, would its area be the square of one of its sides?" No answer exists because the supposition is logically impossible. God, being perfectly good by nature, cannot command what contradicts His nature.
10. Premise 2: OMVD Exist (Objective Moral Values and Duties)
Objective moral values and duties are affirmed through moral experience.
Properly basic belief: The conviction that some things are objectively good or evil, right or wrong, is foundational—rationally accepted unless defeated by contrary evidence.
Key question: Do we possess overriding defeaters that would undermine our trust in moral experience?
Philosophers reflecting on moral experience see no more reason to distrust it than sensory experience. Just as we believe what our five senses tell us—that a physical world exists—despite their fallibility, we should accept what moral experience tells us absent reason to distrust it: that some things are objectively good or evil, right or wrong.
People failing to see moral truths are handicapped, the moral equivalent of the physically blind. There's no reason to let their impairment question what we see clearly.
Although many people initially express relativistic views, most can be readily convinced that objective moral values exist through concrete examples:
The Hindu practice of suttee (burning widows alive on husbands' funeral pyres)
The ancient Chinese custom of crippling women by tightly binding their feet from childhood to resemble lotus blossoms
The Crusades and the Inquisition—moral atrocities perpetrated in religion's name
Catholic priests sexually abusing children and the institutional cover-up
Actions like rape, torture, and child abuse aren't just socially unacceptable—they're moral abominations
When confronted with such examples, honest inquirers almost invariably agree that objective moral values and duties exist.
11. The Sociobiological Objection
The objection: Evolution and social conditioning shaped our moral beliefs for survival advantage, not for tracking truth; therefore we cannot trust them to correspond to objective morality.
11.1 Expanded Statement
Moral beliefs were ingrained through evolutionary advantage rather than truth-tracking processes.
Therefore, we lack justification for believing premise 2 (that OMVD exist).
11.2 Response
The Genetic Fallacy: This objection explains the origin of a belief but does not address its truth value. Demonstrating evolutionary influence on moral beliefs does not falsify their content (just as demonstrating cultural influence on democratic beliefs does not prove democracy false). A belief's truth is independent of how one came to hold it. One may have acquired moral beliefs through a fortune cookie or reading tea leaves, and they could still be true. In particular, if God exists, then objective moral values and duties exist, regardless of how we learn about them.
Begging the question (assumes atheism): At most, this objection shows that our moral perception evolved. If moral values are discovered rather than invented, then our gradual, fallible apprehension of them no more undermines moral realism than our fallible perception of the physical world undermines physical realism. The objection assumes atheism is true. If there is no God, then evolution selected our moral beliefs solely for survival value, not truth. But that's no reason to think the sociobiological account is true. Indeed, if God exists, then He likely would want us to have fundamentally correct moral beliefs and so would either guide the evolutionary process to produce such beliefs or instill them in us:
Apart from assuming atheism, we have no reason to deny what our moral experience tells us.
Self-defeating (Evolutionary Argument Against Naturalism): If all beliefs (including evolutionary theory itself) are selected for survival rather than truth, then global skepticism follows, which undercuts the objection itself. Given naturalism's truth, all our beliefs, not just moral beliefs, result from evolution and social conditioning. Thus, the evolutionary account leads to skepticism about knowledge generally. But this is self-defeating because then we should be skeptical of the evolutionary account itself, since it too is the product of evolution and social conditioning.
11.3 Supporting Quote
Reference: https://en.wikipedia.org/wiki/Evolutionary_argument_against_naturalism
12. Argument Map
13. Summary
If God does not exist, then objective moral values and duties do not exist.
Objective moral values and duties do exist (grounded in moral experience and the absence of successful defeaters).
Therefore, God exists.
The argument's force rests on considerations of ontological grounding (premise 1) and moral experience combined with moral realism (premise 2). The principal challenges—atheistic moral realism, humanism, evolutionary skepticism, and the Euthyphro dilemma—are addressed through careful analysis of ontological grounding, normativity, ultimate accountability, and the nature of divine goodness.
The argument map above illustrates the dialectical exchange between proponents and critics, showing how each objection is met with a reasoned response that strengthens the overall case for God's existence as the necessary foundation of objective morality.
References
[1] William Lane Craig and Paul Kurtz, "The Kurtz/Craig Debate," in Goodness without God is Good Enough, ed. Robert Garcia and Nathan King (Lanham, MD: Rowman & Littlefield, 2008), 34.
[2] Charles Darwin, The Descent of Man and Selection in Relation to Sex, 2nd edition (New York: D. Appleton & Company, 1909), 100.
[3] William Lane Craig and Walter Sinnott-Armstrong, God?: A Debate between a Christian and an Atheist (New York: Oxford University Press, 2003), 34.