…and that should scare us.
A man I know once called me “a ■■■■.ing indoctrinated idiot.”
And the most interesting thing was the reason why he insulted me. What he found indoctrinated was my refusal to regard human beings and non-human animals as ontologically and morally equivalent.
I wasn’t denying that humans are animals biologically, I was saying that a human being possesses a fundamental dignity which does not depend upon intelligence, self-awareness, usefulness, independence, or the cognitive abilities he happens to be exercising at a particular moment.
My acquaintance rejected precisely that premise.
What makes the episode more interesting is that, outwardly, he was a perfectly decent person. I did not experience him as cruel, antisocial or morally indifferent. On the contrary, he had moral convictions strong enough to regard me as morally corrupted by indoctrination.
That is important, because one of the most comforting (for many; not for me) arguments about secular morality runs like this: “Look, people don’t need God to be good. Atheists love their families, help strangers, condemn injustice and sacrifice themselves for others. Therefore morality is safe without transcendence.”
The first sentence is obviously true, it’s the second that worries me.
If the disappearance of God simply turned human beings into visibly amoral beasts, if atheism reliably produced people incapable of love, loyalty, compassion or conscience, the problem would almost solve itself, and the necessity of some transcendent moral order would become glaringly obvious. We would look at what humanity became without it and immediately understand what had been lost.
But that is not what happens.
We remain moral.
We remain capable of tenderness and outrage.
We remain capable of calling other people evil.
And that means something much more disturbing is possible: we can possess a powerful conscience while being profoundly wrong about what that conscience is telling us.
Matter and the missing “ought”
This argument requires a careful definition, because atheism doesn’t logically and intrinsically entail moral nihilism. An atheist may believe in irreducible moral facts. Erik Wielenberg, for example, explicitly defends “godless normative realism.” The argument begins only when we add reductive materialism: the claim that reality is exhausted by natural facts and that there are no irreducible normative properties outside that order.
Once that premise is accepted, the difficulty is severe.
A complete physical description of a murder could tell us that a projectile entered a body; tissue was destroyed; nociceptors fired; consciousness ended; relatives experienced grief.
No increase in physical detail converts any of those descriptions into “therefore this ought not to have happened”.
J. L. Mackie begins Ethics: Inventing Right and Wrong with the deliberately blunt claim that “there are no objective values.” His argument from queerness asks what kind of property objective wrongness could possibly be if, unlike ordinary natural properties, simply apprehending it somehow supplied a categorical reason for action. His alternative is error theory: human beings objectify their attitudes and experience them as features of reality. https://courses.edx.org/c4x/GeorgetownX/phlx101-01/asset/marquis.pdf
Now, the PDF link above is to Marquis rather than Mackie, so the safer Mackie text is the Colorado scan already discussed: https://spot.colorado.edu/~heathwoo/readings/mackie.pdf
Evolutionary explanations make the problem sharper. Sharon Street asks why natural selection, which selects traits for reproductive success rather than philosophical accuracy, should have produced evaluative intuitions reliably aligned with independent moral truth. https://sites.pitt.edu/~mthompso/readings/street.pdf
Richard Joyce gives the unsettling hypothesis its cleanest form: selection may have produced creatures disposed to “invest the world with values that it does not contain.” The important thing is not whether every detail of that evolutionary genealogy is established. It is that materialism already possesses the resources to explain why morality feelsobjective without presupposing that objective morality exists.
Parents who fiercely protect children survive.
Groups that punish defectors can outcompete groups that do not.
Empathy facilitates cooperation.
Guilt modifies behaviour.
Disgust protects boundaries.
Loyalty binds coalitions.
None of this requires evolution to have discovered a metaphysical property called wrongness.
So the austere materialist faces a choice. He may identify morality with some natural property—flourishing, preference satisfaction, suffering—or he may deny that moral prescriptions are properties waiting to be discovered in the natural world at all.
The first route immediately raises the question: why that natural property? The universe contains suffering, but why should the existence of suffering, considered merely as a physical and psychological fact, contain the further command therefore nobody ought to cause it? A materialist can care enormously about suffering. What materialism alone does not establish is why somebody who does not care has made a metaphysical error rather than simply possessing different preferences.
The second route does not remove the difficulty; it changes its form. If the prescriptive force of morality is projected rather than discovered, then moral judgments no longer report irreducible normative properties in reality. Mackie’s own conclusion is error theory: ordinary moral discourse presents its claims as objectively binding, while the objective prescriptivity it presupposes does not exist.
An expressivist may resist calling this an “error” by treating moral judgments as expressions of attitudes, commitments or prescriptions rather than descriptions of facts. But that can explain why we condemn cruelty without yet establishing that someone who sincerely approves of cruelty has failed to perceive an objective feature of reality. Constructivism offers a more ambitious alternative by grounding normativity in rational agency, ideal deliberation or principles of justification; yet this too requires an additional normative framework whose authority must itself be defended.
The dilemma remains; If morality is identified with a natural property, the materialist must explain why that property is categorically normative; If morality is projected, expressed or constructed, he must explain in what sense its authority is discovered rather than generated by human evaluative activity.
That is why Mackian error theory is such a natural resting point for reductive materialism.
And it leads to a strange conclusion, namely that moral nihilism need not produce morally indifferent people.
The nihilist’s brain can continue generating love, guilt, indignation, compassion and moral certainty.
The machinery survives after its metaphysical warranty has expired.
Why the human animal becomes difficult to privilege
My argument with my acquaintance was indeed deeper than it initially appeared.
If human beings possess no intrinsic dignity simply by being the kind of beings they are, then moral status must depend upon some additional property.
Sentience.
Intelligence.
Self-consciousness.
Autonomy.
Ability to formulate desires.
Capacity to imagine one’s future.
But these properties come in degrees.
And once dignity tracks performance, there is no reason for moral status to respect the species boundary.
Michael Tooley embraces this consequence in “Abortion and Infanticide.” His account makes psychological capacities central to the serious right to life; accordingly, human fetuses and newborns can fail the test while sufficiently developed non-human animals may fare better. He therefore has no principled reason to preserve the proposition that every human being possesses a status categorically superior to every animal. (Philosophy & Public Affairs 2.1, 1972, pp. 37–65.) https://eclass.uoa.gr/modules/document/file.php/PPP504/Michael%20Tooley%2C%20Abortion%20and%20infanticide.pdf
This is not a cheap reductio of Tooley, it’s the consistency of his premise.
And Dr Calum Miller (an Oxford-trained physician as well as a bioethicist) has recently pressed exactly the opposite argument from human equality. In Journal of Medical Ethics he begins from a remarkably modest proposition: ordinary non-disabled adult humans are moral equals. Properties such as intelligence, consciousness and psychological sophistication vary by degree. If those gradated properties ground inherent worth, then equal human worth becomes extremely difficult to explain. Miller therefore argues that the more plausible basis of fundamental equality is possession of a non-gradated property: being an individual human organism. Fetuses possess that property. (J Med Ethics 49, 2023, pp. 569–572.)
His argument is worth stating formally:
- Fundamental human equality must rest either on a property possessed equally or on properties possessed by degree.
- Intelligence, sentience, self-awareness and rational performance exist by degree.
- If one of these grounds fundamental worth, humans with greater quantities should possess greater fundamental worth.
- But our basic commitment to human equality denies precisely that conclusion.
- Therefore fundamental equality plausibly rests on something we possess equally as individual human beings.
- Fetuses are individual human beings.
- Therefore the fetus cannot be excluded merely because its present abilities are undeveloped.
One may dispute premise four or five, several bioethicists do, but the price of rejecting them should be stated honestly: one needs an alternative explanation of why the intelligent adult, the ordinary adult, the severely disabled adult and the newborn possess exactly equal fundamental status despite dramatic differences in the properties usually invoked to explain personhood. Miller’s critics have engaged precisely this difficulty.
The first question in abortion is biological, but the decisive one is philosophical
There is one claim medicine can help settle.
An embryo is not a gamete or merely a piece of maternal tissue.
Miller and Alexander Pruss devote an entire Bioethics article to the organismic question and conclude that there are strong grounds for holding that a new human organism begins to exist at fertilization. Importantly, they explicitly say that this does not by itself establish personhood. That distinction is crucial. (Bioethics 31.7, 2017, pp. 534–542.) https://calumsblog.com/wp-content/uploads/2015/02/pruss-paper-in-journal.pdf
Standard medical embryology describes fertilization as the formation of the zygote, followed by a coordinated developmental process rather than the assembly of a human being from independent parts. Langman’s Medical Embryology, for example, lists among the consequences of fertilization the restoration of diploid chromosomes, determination of chromosomal sex and initiation of cleavage.
The medical fact therefore gives us this much: there is a living developing human organism.
Medicine cannot append: therefore intentionally killing it is murder.
That is philosophy.
But several sophisticated philosophers have argued exactly that conclusion without relying upon Scripture.
Don Marquis’s “Why Abortion Is Immoral” remains perhaps the best-known secular example. Marquis deliberately avoids beginning with the controversial word person. He asks instead why killing an ordinary adult is one of the gravest wrongs, and his answer is that killing deprives the victim of an entire future of value (relationships, experiences, projects, pleasures, knowledge, everything the victim would otherwise have had). The fetus has such a future in exactly the deprivation-relevant sense. Hence abortion, he argues, is prima facie in the same moral category as killing an innocent adult. (Journal of Philosophy 86.4, 1989, pp. 183–202.) https://courses.edx.org/c4x/GeorgetownX/phlx101-01/asset/marquis.pdf
The power of Marquis’s argument is that it asks us to use the same theory of killing on adults and fetuses: If what primarily makes my murder wrong is not my present ability to articulate my desire to live but the future stolen from me, then lack of currently sophisticated psychology does not obviously remove the wrong.
Patrick Lee approaches the issue through substantial identity (and he makes an argument I appreciate even more): his argument is that the embryo does not become the same individual only after acquiring consciousness; consciousness is something the already-existing organism later develops. In Abortion and Unborn Human Life he argues that intentionally killing that individual cannot be justified merely by pointing to its current immaturity. The book explicitly defends the proposition that the unborn are human individuals with full basic moral worth.
There is then an unusually interesting argument from the other side.
Kate Greasley’s Arguments about Abortion is not a pro-life book. Yet her chapter “Abortion as Justified Homicide” asks what follows if fetal personhood is conceded, and her conclusion is that ordinary abortion fits very badly into the conventional categories by which killing persons is normally justified: self-defence, necessity, or related doctrines. In her words, if normal abortion were justified homicide, it would be an exceptionally anomalous form of it.
That matters because it identifies the real hinge of the debate.
The easiest philosophical defence of abortion is not “Yes, this is a person, but killing him is ordinarily justified”, it instead is “This is not yet a person of the relevant sort.”
Which brings us straight back to the question of who counts.
Moral risk
Even somebody unconvinced by Marquis, Lee or Miller must face a second problem.
What probability should we assign to our own moral fallibility?
Dan Moller frames this as moral risk. His historical example is John Newton, who participated in the slave trade before becoming an abolitionist. Newton had not lacked access to the empirical reality of slavery. He had seen it.
Looking back, he wrote: “Custom, example, and interest had blinded my eyes.”
Moller’s point is that human beings can know the relevant non-moral facts while being grotesquely mistaken about their moral significance. He then applies precisely this lesson to abortion: even after concluding that the arguments against abortion fail, there can remain a non-negligible possibility that the judgment is catastrophically wrong. (Philosophy 86.3, 2011, pp. 425–443, especially pp. 433–434.) https://www.cambridge.org/core/services/aop-cambridge-core/content/view/C4E02BAE7D49B2B59B2C1D55B03A2B34/S0031819111000222a.pdf/abortion_and_moral_risk1.pdf
Matthew Braddock has recently pushed the moral-risk argument further: one need not be certain that abortion constitutes homicide for the possibility of homicide to carry serious normative weight. His 2026 paper explicitly distinguishes uncertainty about personhood, personal identity and the wrongness of killing and asks what precautions are appropriate when the possible error is the unjust killing of a person. If abortion substantially risks homicide, it should be illegal - PMC
I don’t need to accept Braddock’s legal conclusion to accept the epistemic question, If I am unsure whether a dark figure in the woods is a man or a cardboard target, I cannot normally answer “ I have arguments suggesting it probably isn’t a man, therefore I may shoot.”
The more serious the possible moral harm, the more our uncertainty matters.
A doctor making the case from equality
Miller’s work is especially interesting because he combines clinical training with philosophical argument rather than pretending that medicine itself settles personhood.
His 2023 equality argument is simple enough to be dangerous.
If fetuses lack fundamental status because they are less conscious, less rational or less autonomous, then these properties are doing the moral work.
But every one of them is scalar.
Some adults are vastly more intelligent than others.
Some are more autonomous.
Some have richer self-consciousness.
If degree of those properties determines basic moral worth, equal fundamental human dignity becomes difficult to preserve.
Miller’s proposed escape is to distinguish basic worth from the developed manifestation of capacities. We are not equal because we perform equally, we are equal because we are equally individual human beings of the kind whose mature members characteristically possess rational capacities.
The argument may ultimately fail, but it cannot be answered merely by saying science says fetus.
“Fetus” is a developmental stage, just as “infant” and “adolescent” are developmental stages.
It tells us how mature the organism is, it doesn’t tell us how much the organism is worth.
Why abortion could become a future moral atrocity
No serious philosopher can prove how the twenty-second century will judge us, but we can ask what would follow if the pro-life account of moral status is correct.
Dr Calum Miller makes the comparison very explicit in The Journal of Medicine and Philosophy. Writing from the pro-life premise that unborn humans possess equal moral status, he argues that abortion differs from miscarriage precisely because one is natural death and the other involves intentional, systematic human killing. He says comparisons with mass killing, including the Holocaust, are useful for understanding why someone who accepts fetal equality could regard abortion as an issue of extraordinary moral seriousness. Importantly, this is presented as the implication of the pro-life premise, not as proof of that premise. (Journal of Medicine and Philosophy 48.3, 2023, pp. 225–242.)
And Justin Buckley Dyer’s Cambridge study of slavery and abortion documents how the analogy has repeatedly arisen around the same question of equality and exclusion. Dyer himself warns against crude historical equivalences, but argues that the philosophical and constitutional parallels deserve serious analysis.
That provides a rational basis for the prediction without pretending it is prophecy.
If future moral philosophy concludes that prenatal humans possessed the same fundamental protection all along, our descendants will not merely think that we selected the wrong gestational limit, they will see an enormous category error.
They may ask how a civilization which spoke constantly of human rights could deliberately exclude millions of humans because they had not yet reached an approved level of development.
And that question will sound disturbingly familiar.
Slavery, the Shoah and the problem of membership
The comparison must remain exact, lest we fall into parody and unseriousness.
Abortion is not chattel slavery.
It’s not the Holocaust.
Those historical phenomena involved born, socially interacting people subjected respectively to ownership and racialized genocidal persecution, while pregnancy involves a unique bodily relationship between two organisms, and bodily autonomy introduces a consideration for which neither analogy has a perfect equivalent.
The real analogy lies elsewhere, because a moral rule always contains two questions:
- What is owed?
and
- To whom is it owed?
A civilization may answer the first beautifully while answering the second catastrophically.
Slavery demonstrates that people can affirm moral principles while excluding human beings from their equal application.
The history of Nazism makes the phenomenon even more disturbing because Nazi ideology did not simply abolish morality.
Claudia Koonz’s The Nazi Conscience is built around exactly that point. Nazi morality was particularist: duty, sacrifice, loyalty and reciprocity remained virtues, but the moral community was racially restricted. Nazis could regard themselves as defending a morally righteous Volksgemeinschaft precisely because outsiders had been expelled from the relevant universe of obligation.
And the primary sources are worse.
In his Posen speech of 4 October 1943, Heinrich Himmler spoke to senior SS officers about mass killing using the vocabulary of moral right, duty and decency. He simultaneously insisted that SS men must not enrich themselves from murdered Jews: murder could be interpreted as duty while theft remained dishonourable. That grotesque coexistence is preserved in the Nuremberg documentary record. Nuremberg - Document Viewer - Extracts from speeches to senior SS officers, concerning the activities of the SS during the war and plans for the future, including the extermination of the Jews
This is why Reinhard Heydrich matters too.
His monstrosity would be easier to understand if he were incapable of ordinary human valuation, but he wasn’t . Robert Gerwarth records Heydrich’s 1939 instructions concerning the moral formation of his own children: they were to be disciplined toward themselves, generous toward their own people, and merciless toward enemies of the Reich. The page reference is Gerwarth, Hitler’s Hangman, p. 139, independently documented in Uğur Ümit Üngör’s scholarly review.
That is not amorality.
It is moral particularism turned murderous.
The virtues remain.
The boundary changes.
And this is precisely what makes the comparison to slavery and abortion philosophically relevant without making the historical events equivalent.
The underlying question is who is inside the circle?
The most frightening possibility
This finally explains why “we can be moral without God” doesn’t reassure me and, I argue, shouldn’t reassure anybody.
Imagine the opposite world.
Suppose that whenever belief in transcendence disappeared, people immediately became visibly monstrous. Parents stopped loving children. Friends betrayed one another. Compassion disappeared. Murder became casual. Nobody experienced guilt.
In such a world, the argument for transcendence would be almost embarrassingly easy.
We would know what had been removed because we could see the moral faculty collapse with it.
Our actual world is much harder, because an atheist can be extraordinarily kind, a materialist can sacrifice himself for another person, my acquaintance could be outwardly decent and sincerely convinced that his rejection of human exceptionalism made him more moral, not less.
And Nazis could possess codes of duty, loyalty, sacrifice and honour while committing crimes which now stand among our paradigms of evil.
This suggests that moral psychology is frighteningly independent of moral truth.
If reductive materialism is correct, that independence becomes even more intelligible: nature only had to produce organisms with powerful evaluative dispositions, it didn’t have to give those organisms access to a transcendent order.
So we can remain deeply moral after transcendence disappears.
We can be compassionate.
We can be righteous.
We can be disgusted by injustice.
We can call someone else a ■■■■■■■ indoctrinated idiot because his moral premises offend ours.
And none of those psychological facts guarantees that we have drawn the boundary correctly.
That is why abortion matters so much to this argument: If the fetus is not the kind of being entitled to fundamental protection, the comparison with slavery and the Shoah collapses at precisely that point, but if Marquis, Lee, Miller or related arguments are broadly correct, if the being killed already possesses the same fundamental status that later belongs to the infant and adult, then abortion becomes something morally enormous.
Not because Scripture said so, not because the Church said so, not because an ultrasound is emotionally moving.
But because a civilization outwardly committed to human equality would have solved the contradiction by changing the definition of who counts as one of us.
And history gives us no reason whatsoever to believe that civilized, educated, outwardly decent people are incapable of doing exactly that, actually it proves the very opposite!
Perhaps the most dangerous sentence in ethics is not “nothing is good or evil”, it may well be “of course good and evil exist. We simply know which beings they apply to”.