Home / A. Sentience and moral status / Part DIR
"Animals don't have souls."
the existence of a soul can't be publicly verified and, even in the traditions that affirm it, it doesn't authorize causing suffering. The word "animal" itself comes from the Latin anima, soul; classical philosophy attributed souls to animals; and the great religions condemn cruelty. What matters morally, the capacity to suffer, exists with or without an immortal soul.
Note on tone: this chapter doesn't discuss whether God or the soul exists. It discusses whether belief in an exclusively human soul justifies causing suffering to other beings, and shows that religious traditions themselves usually answer no.
Short answer
No one can prove who has a soul and who doesn't, so that can't be the criterion for deciding whom we may make suffer. The word "animal" itself comes from the Latin anima, meaning soul. And religions usually condemn cruelty: the Catechism of the Catholic Church says "it is contrary to human dignity to cause animals to suffer or die needlessly". Finally, if an animal has no afterlife, this life is all it has, which makes taking it even more serious.
For children
Some people believe only humans have souls, others believe animals do too, and every family can talk about this. But there's one thing everyone can see: when a dog gets hurt, it feels pain, and when it's left alone, it can get sad. To know whether it's wrong to hurt someone, we don't need to know whether they have a soul. It's enough to know they feel. And almost all religions teach us to take good care of animals.
"If only the soul matters, why does your own religion condemn cruelty to animals?"
Como pode aparecer
"Animals have no spirit."
"When an animal dies, that's it."
"Animals don't go to heaven."
"Vegans think chickens have souls."
"Are you going to pray for the chicken's soul?"
"Only man was made in the image and likeness of God."
"God gave us animals to serve us." (developed in D4)
"Animals are complex machines, without minds."
"Human life is sacred; animals are resources."
The strongest version
"Animals don't have souls, so there's no problem killing them."
Strongest version (steelman). In its most elaborate theological form, inspired by Thomism:
- P1A being's full moral value comes from having a rational, immortal soul, created by God.
- P2Only humans have a rational, immortal soul.
- C1So only humans have full moral value.
- P3Beings without full moral value were entrusted by God to human use.
- C2So using animals for food and other purposes is permitted.
There's also a Cartesian version, not religious in the same sense: without a soul (mind), animals would be complex machines that react but don't feel. That version denies sentience and is dealt with in A5.
The theological argument is valid. Its soundness problems are of three kinds: P1 and P2 can't be assessed by public criteria; "soul" is used in different senses; and P3 doesn't authorize what is practiced today, not even according to the religious traditions that hold it.
Full answer
- a
Reconstruction and diagnosis
"Soul" has at least three senses, and the argument only seems to work when they're mixed together.
Sense of "soul" What happens to P2 What happens to P1 Principle of life and sensation (Aristotle, Thomas Aquinas) False: in this tradition, animals have a sensitive soul, which perceives, desires and feels Loses its meaning: having a soul doesn't separate humans from animals Mind or consciousness (popular usage) False in light of the evidence of sentience (see A5) Comes close to sentientism Rational, immortal soul (theology) Can't be verified or refuted by public evidence Doesn't explain why the pain of a being without immortality wouldn't matter In the Aristotelian tradition, which shaped medieval Christian thought, there are three levels of soul: nutritive (plants), sensitive (animals) and rational (humans). In other words, the philosophy that gave rise to the argument attributed souls to animals. What it denied was the rational soul.
- b
Where the argument breaks
1. The premise can't be examined by everyone (P1 and P2).
Who has an immortal soul is a matter of faith, not shared evidence, and traditions disagree among themselves. In Jainism and strands of Hinduism, all living beings have a spiritual principle; in Buddhism, rebirth crosses species. Choosing one specific theology's answer to authorize harm to others is special pleading. This isn't an attack on faith: it's the demand that a criterion used to justify suffering be accessible to those who don't share the same belief.
2. Even in traditions that affirm a uniquely human soul, cruelty is condemned.
The table in (c) shows that Christianity, Judaism, Islam, Hinduism and Buddhism have explicit teachings against making animals suffer. Those who use A4 usually attribute to religion a license it doesn't grant.
3. Immortality isn't what makes pain bad.
Pain is bad while it's felt, here and now. Having or not having an afterlife doesn't change what an animal feels in confinement or at slaughter. There's even reason to think the opposite: if there's no compensation after death, this life is the only one the animal has, and the harm of taking or ruining it is final. C. S. Lewis, one of the most widely read Christian apologists of the 20th century, treated animal suffering as a serious problem precisely for this reason (The Problem of Pain, 1940).
4. The criterion ends up reduced to species.
In practice, the rational soul is attributed to every human and denied to every animal, regardless of each one's capacities. So "having a soul" works as another name for "being human", and the argument becomes A10 ("they're just animals") in theological vocabulary.
- c
Data and sources: what the traditions say
The table doesn't claim religions are vegan. It shows they don't authorize unnecessary suffering, and honestly records where they allow the use of animals.
Tradition What it says Source Honest note Catholicism "It is contrary to human dignity to cause animals to suffer or die needlessly" Catechism of the Catholic Church, § 2418 The previous paragraph (§ 2417) considers it legitimate to use animals for food and clothing. The question is what counts as "needlessly" when there are alternatives Catholicism Rejects the idea that being created in God's image and given dominion over the earth justifies "absolute domination over other creatures" Pope Francis, Laudato Si' (2015), § 67, quoted here The encyclical recognizes the creatures' own value, but doesn't deal directly with industrial livestock farming Christianity and Judaism (Hebrew Bible) "A righteous man regardeth the life of his beast"; in Eden, the diet described is plant-based; the prophetic vision of peace includes the wolf and the lamb Proverbs 12:10; Genesis 1:29-30; Isaiah 11:6-9 Other texts, such as Genesis 9:3, permit eating meat Judaism The principle of tza'ar ba'alei chayim: a prohibition on causing animals unnecessary suffering Babylonian Talmud, Bava Metzia 32b Coexists with rules of ritual slaughter Islam A woman was punished for shutting a cat up until it died without giving it food or water; a prostitute was forgiven for giving water to a thirsty dog Sahih al-Bukhari 3482 and 3321 Coexists with rules of ritual slaughter Hinduism and Jainism Ahimsa, non-violence toward living beings; in Jainism, all living beings have a soul (jiva) Textual tradition and practice Jainism takes the principle further than any other major tradition Buddhism The first precept: to abstain from taking the life of living beings Textual tradition Dietary practice varies between schools and countries - d
The strongest counter-reply: human dignity and religious permission
The most solid version doesn't say animals don't matter. It says humans have a unique dignity, grounded in the rational soul and the image of God, and that God permitted the use of animals, provided there's no cruelty. On this reading, eating meat would be compatible with faith, and veganism would demand more than religion does.
- e
Why the counter-reply doesn't reach the conclusion
The permission's own limit condemns current practice.
The permission comes with the condition of not causing unnecessary suffering. When there are food alternatives and the dominant system involves confinement, mutilation and slaughter on an industrial scale, most of that suffering is unnecessary by the tradition's own standard.
Dignity creates duties, not license.
In the Abrahamic traditions, humans receive animals as stewards caring on another's behalf, not as absolute owners. Laudato Si' itself rejects absolute domination. There's even a strand of Christian theology that defends animals on the basis of faith (Linzey, 1994).
Permission isn't obligation.
Even if religion permits eating meat, none requires it. Choosing not to cause suffering remains available within all these traditions.
Faith and sentientism are compatible.
It's possible to believe only humans have immortal souls and, at the same time, recognize that animal suffering matters. There's no contradiction between the two beliefs; the contradiction lies in condemning cruelty while funding it when it can be avoided.
Reasoning errors
Logical
Is the form valid?
Equivocation
Non sequitur
Begging the question
Special pleading
Epistemological
Does the evidence support it?
Unfalsifiable premise
Selective reading of texts
Not knowing one's own tradition
Moral
Is the criterion coherent?
Irrelevant criterion
Dignity as license
Lack of public justification
Biases
Psychological essentialism
The tendency to think categories have an invisible essence makes the "soul" seem a natural boundary between humans and animals
Medin and Ortony, 1989; Gelman, 2003
Motivated reasoning
Religion is searched for a justification of a practice one already wants to keep
General literature on motivated cognition
Confirmation bias in reading texts
The passages that permit use are remembered and those that condemn cruelty are forgotten
A known pattern in interpreting authoritative texts
Deference to authority
"Religion says so" closes the analysis before it starts
A known pattern of appeal to authority
Motivated denial of mind
Denying a soul to eaten animals is a way of denying them a mind
Bastian et al., 2012; replicated by Jacobs et al., 2024
Extrapolations
The principle being tested is: "whoever lacks a (rational) soul may be used".
If it applied to…Peoples considered "without reason" or "without a full soul"Tap to see
It would be enough to claim a human group lacks a full rational soul to justify using them. Since possession of a soul can't be verified, those with power decide whom it belongs to
In the 16th century, some argued that the Indigenous peoples of the Americas should be treated "as dumb brutes created for our service". The bull Sublimis Deus (1537) replied that they were "truly men" and could not be enslaved
If it applied to…Human physical sufferingTap to see
Bodily pain would be morally secondary. If value lies only in the immortal soul, and the soul isn't hurt by physical pain, relieving a sick person's pain would matter less than it seems
Religious traditions do the opposite and treat care for the suffering body as a duty
If it applied to…Different religious traditionsTap to see
Each religion could impose its own answer about souls on everyone. If the soul decides, a Jain could require everyone to treat insects as ensouled beings, with the same right as those who deny souls to cattle
Shows why the criterion for authorizing harm must be public, not dependent on a specific faith
If it applied to…Conscious beings without a recognized soulTap to see
Sentient extraterrestrials or a conscious artificial intelligence could be tortured. If they lack the soul a certain tradition attributes to humans, their suffering wouldn't count
Whoever feels this would be wrong is appealing to sentience, not to the soul
Contradictions
Almost everyone who uses A4 thinks it wrong to torture an animal, and so do their religions. That only makes sense if animal suffering matters, soul or no soul.
Many people who say animals have no souls hope to meet their dog or cat again "in a better place" or speak of its "good soul", but don't extend that idea to the pig or the cow.
The traditions speak of responsibility and compassion; the argument uses them to close the conversation about responsibility.
If only the immortal soul mattered, human physical pain would also be secondary. Yet the same religions run hospitals and teach the relief of bodily suffering.
What the argument gets right
What is true
The argument expresses an intuition that deserves respect: that there's something special about human life and that we have a responsibility no other animal has. For billions of people, this intuition is lived through faith, and an honest book needn't attack it. It's also true that the ultimate nature of consciousness remains an open question in philosophy and science: no one can fully explain why subjective experience exists.
But
But none of these points leads to the conclusion that we may make animals suffer needlessly. The special responsibility traditions attribute to humans is, in almost all of them, a responsibility to care. And uncertainty about the nature of consciousness doesn't erase the evidence that animals feel.
Connections
Usually comes before
Usually comes after
Go deeper in Questão de Ética
Chapters from the open-access collection A Journey Through Animal Ethics that discuss this argument in more detail:
- Could Metaphysical Characteristics Justify Speciesism? Vol. I, ch. 3
References
Provisional author-date format. The links indicate the sources checked in writing this chapter.
Religious texts and teaching
- Bible: Genesis 1:29-30 and 9:3; Proverbs 12:10; Isaiah 11:6-9.
- Catechism of the Catholic Church, § 2415-2418.
- Laudato Si', § 67 and § 130. Passages checked at Catholic Moral Theology.
- *Sublimis Deus*.
- Sahih al-Bukhari 3482 and 3321.
- Babylonian Talmud, Bava Metzia 32b.
Philosophy and theology
- Aristotle. On the Soul (De Anima), book II.
- Discourse on Method, part V.
- The Problem of Pain, chapter on animal pain.
- Animal Theology. SCM Press.
- Thomas Aquinas. Summa contra Gentiles, book III, ch. 112.
Psychology
- The Essential Child: Origins of Essentialism in Everyday Thought. Oxford University Press.
- Replication registered report of Bastian et al. (2012). *International Review of Social Psychology*.
- Psychological essentialism. In S. Vosniadou & A. Ortony (Eds.), Similarity and Analogical Reasoning. Cambridge University Press.