Ethics tree · where our rules came from, and where they go
Rules for living together are older than writing and older than our species. Think of cells that police cheats, bats that repay a meal, chimpanzees that make peace. Nodes in the first band are marked as observed in living species or inferred for ancestors. Written law and revealed religion came next. Beside them, from the start, ran traditions that did without a divine lawgiver: Confucian, Jain and Buddhist ethics, Indian materialism, then the Greek and later European line that asks how to behave once no god is watching. After them come rules for your own experience, and the long widening of who the rules protect, with its cost to wild and authentic lives. The tree ends in open questions. None is answered here.
Start here
Where it starts
Everything grows from one root: , the oldest rule there is. From there the tree branches towards bodies, families and societies.
Your progress stays in this browser only. If you clear site data, the tree starts over.
The whole tree as text · every node in order, for screen readers, text browsers and machine readers. Same nodes as the map
Dates are years of the common era unless marked BC or BCE. Evolutionary dates are in years ago. Each node has a stable address, shown after it. We don’t answer the open questions here. Each one lists the closest published thinking.
Unwritten rules
Stop the free rider (origin undated; tested 2004 · Observed in living species)
Many bacteria release costly molecules, such as iron-scavenging siderophores, that help every cell nearby. Mutants that stop paying the cost but still use the product can spread. Griffin, West and Buckling (2004) showed in Pseudomonas aeruginosa that how much cooperation survives depends on two things. One is how closely related the neighbours are. The other is the scale at which they compete.
Led to: The multicellular bargain; Pool your genes
Address: /trees/ethics?n=e-pubgoods
The multicellular bargain (at least 1 billion years ago · Inferred for ancestors)
In a multicellular body most cells give up their own reproduction. Only the germ line passes on genes. That’s a cooperative bargain among cells. The oldest securely dated fossil with differentiated cells is the red alga Bangiomorpha, about 1.05 billion years old. Claims for older multicellular eukaryotes exist. The true origin is earlier, and it has happened many times.
Built on: Stop the free rider
Led to: Cancer breaks the rules
Address: /trees/ethics?n=e-multicell
Pool your genes (more than 1 billion years ago · Inferred for ancestors)
In sexual reproduction, two individuals each give half the genome of the next generation. It’s a joint act, so cells needed rules about whose genes pass on. Comparative genomics indicates that meiosis and sex were already present in the last common ancestor of living eukaryotes. So the practice is well over a billion years old.
Built on: Stop the free rider
Led to: Care for the young
Address: /trees/ethics?n=e-sex
Care for the young (about 450 million years ago · Inferred for ancestors)
Ordovician ostracod crustaceans, about 450 million years old, were preserved with eggs and embryos held inside the shell. That’s direct fossil evidence of brood care. Care means paying a cost to protect another individual’s survival. This is the oldest case in this tree.
Built on: Pool your genes
Led to: Help your relatives
Address: /trees/ethics?n=e-parental
Help your relatives (rule stated 1964 · Idea)
Hamilton (1964) showed that a gene for helping others can spread. It spreads if the cost to the helper is smaller than the benefit to the one helped, weighted by how closely they’re related. This inclusive-fitness rule is the standard starting point for explaining why animals help their kin.
Built on: Care for the young
Led to: Return the favour; One queen, many workers; Feed the hungry roost-mate; Warn the family; Make peace after a fight; The Expanding Circle
Address: /trees/ethics?n=e-kin
Return the favour (theory 1971, 1981 · Idea)
Trivers (1971) argued that helping non-relatives can evolve when helpers are likely to meet again and the favour is returned. Axelrod and Hamilton (1981) ran a computer tournament. It showed that conditional cooperation can last among self-interested players.
Built on: Help your relatives
Led to: Feed the hungry roost-mate; Fair shares; Share, and be owed
Address: /trees/ethics?n=e-reciprocity
Cancer breaks the rules (as old as multicellularity · Observed in living species)
Aktipis and colleagues review cancer as a failure of cooperation among cells. It breaks the rules on limiting division, dying on schedule, dividing labour, sharing resources and keeping the surrounding tissue intact. They find cancer-like disorganised growth in every form of multicellular life they examined.
Built on: The multicellular bargain
Led to: Police the egg-layers
Address: /trees/ethics?n=e-cancer
Police the egg-layers (observed 1989 · Observed in living species)
In honeybee colonies, workers eat eggs laid by other workers. That way the queen’s offspring are the ones raised. Ratnieks and Wenseleers reviewed such policing across insect societies. They describe it as a way of suppressing individuals that breed at the colony’s expense.
Built on: One queen, many workers; Cancer breaks the rules
Led to: Rules for synthetic minds
Address: /trees/ethics?n=e-police
Feed the hungry roost-mate (observed 1984 · Observed in living species)
Wilkinson (1984) found that wild vampire bats bring up blood for roost-mates that failed to feed. Sharing depended on relatedness and on the chance to return the favour, each on its own. A later study by Carter and Wilkinson found that past help predicts sharing better than relatedness does. Reciprocity there was supported, not demonstrated.
Built on: Return the favour; Help your relatives
Source: Wilkinson, ‘Reciprocal food sharing in the vampire bat’, Nature 308 (1984) 181–184
Address: /trees/ethics?n=e-bats
Warn the family (observed 1983 · Observed in living species)
Hoogland (1983) studied alarm calling in black-tailed prairie dogs. He reported that callers are more likely to warn when close relatives are nearby. Later summaries extend the pattern to more distant kin.
Built on: Help your relatives
Address: /trees/ethics?n=e-prairie
Fair shares (observed 2003 · Observed in living species)
Brosnan and de Waal (2003) reported that capuchin monkeys refused a reward they had accepted before, once a partner got a better one for the same task. A Nature commentary argued that the results show rejection of a worse reward when a better one is in view. It said they don’t necessarily show a dislike of inequity.
Built on: Return the favour
Led to: Share, and be owed
Source: Brosnan & de Waal, ‘Monkeys reject unequal pay’, Nature 425 (2003) 297–299
Address: /trees/ethics?n=e-capuchin
Make peace after a fight (observed 1979 · Observed in living species)
De Waal and van Roosmalen (1979) found at Arnhem Zoo that chimpanzees who had fought made body contact soon afterwards. They named this reconciliation. A later study of wild chimpanzees found reconciliation much rarer than in captivity.
Built on: Help your relatives
Led to: Rank and file rule the boss
Address: /trees/ethics?n=e-chimp-repair
Rank and file rule the boss (reconstructed for foragers · Inferred for ancestors)
Boehm (1993) argued, from a cross-cultural survey, that egalitarian foragers keep leaders in check. They band together to ridicule, shun or remove anyone who tries to dominate. He treats this as a reversal of the dominance ordering found in the great apes.
Built on: Make peace after a fight; Share, and be owed
Led to: Shame the boaster
Address: /trees/ethics?n=e-reverse
Shame the boaster (observed 1990s–2005 · Inferred for ancestors)
Wiessner (2005) recorded how the Ju/‘hoansi, foragers of the Kalahari, enforce norms through gossip, criticism and, rarely, group violence. She found that most conflict is handled by talk. Third parties who weren’t harmed do the enforcing. It shows how norms can be kept without a state. These are living people with their own history. So the study is evidence about how enforcement works, not a portrait of our ancestors.
Built on: Rank and file rule the boss
Led to: First written laws; Do no harm to any life; Roles, ritual and humaneness; The five precepts; Rules for synthetic minds
Source: Wiessner, ‘Norm enforcement among the Ju/‘hoansi Bushmen’, Human Nature 16 (2005) 115–145
Address: /trees/ethics?n=e-norms
Rules from above
First written laws (c. 2100 BC)
The Code of Ur-Nammu, from the Sumerian city of Ur, is the oldest surviving written law code. It sets fixed payment for injuries. A rule the ruler published took the place of unwritten settlement.
Built on: Shame the boaster
Led to: Hammurabi’s code
Source: Britannica, ‘Ur-Nammu’
Address: /trees/ethics?n=a-urnammu
Hammurabi’s code (c. 1754 BC)
Hammurabi of Babylon had about 280 laws carved on a stele. They state penalties by offence and by the rank of the people involved. The code presents the laws as given by the king under the sanction of the gods.
Built on: First written laws
Led to: The Decalogue; Good because God says so?
Source: Britannica, ‘Code of Hammurabi’
Address: /trees/ethics?n=a-hammurabi
The Decalogue (first millennium BC (dating debated))
The Hebrew Bible gives ten commandments, in Exodus 20 and Deuteronomy 5. They’re framed as rules spoken by God to a people bound by covenant. They cover worship, the sabbath, honouring parents, killing, adultery, theft, false witness and coveting.
Built on: Hammurabi’s code
Led to: The Golden Rule; Love your neighbour; Law from revelation; Reason or revelation?
Source: Britannica, ‘Ten Commandments’
Address: /trees/ethics?n=a-decalogue
The Golden Rule (c. 500 BC onward, many cultures · Idea)
Versions of the rule to treat others as you’d wish to be treated appear in Confucian, Jewish, Christian, Buddhist, Hindu and other writings. Some are worded positively and some negatively. That it recurs across traditions is cited as evidence of a common root in reciprocity among people.
Built on: Roles, ritual and humaneness; The Decalogue; The five precepts
Led to: Love your neighbour
Source: Britannica, ‘Golden Rule’
Address: /trees/ethics?n=a-golden
Live by reason and nature (c. 300 BC onward · Idea)
The Stoics, from Zeno of Citium on, taught that virtue is the only good. A person should live in agreement with reason and nature. Later Stoics such as Hierocles described concentric circles of concern, widening from the self to all humanity.
Built on: The Ring of Gyges
Led to: Natural law
Source: Stanford Encyclopedia of Philosophy, ‘Stoicism’
Address: /trees/ethics?n=a-stoics
Love your neighbour (1st century AD · Idea)
The Sermon on the Mount in the Gospel of Matthew moves rules from outward acts to intentions. It extends concern to enemies. Christianity took the commandments of the Hebrew Bible as its base and added the rule to love your neighbour.
Built on: The Decalogue; The Golden Rule
Led to: Law from revelation; Natural law; Give yourself the law; If there is no God; The death of God
Source: Britannica, ‘Sermon on the Mount’
Address: /trees/ethics?n=a-christian
Law from revelation (7th century AD · Idea)
In Islam, the Quran and the example of Muhammad are the base of the sharia. It’s a body of duties covering worship, family, trade and punishment. Jurists developed the rules through interpretation over the following centuries.
Built on: Love your neighbour; The Decalogue
Led to: Reason or revelation?
Source: Britannica, ‘Sharia’
Address: /trees/ethics?n=a-islam
Reason or revelation? (8th–13th century AD · Idea)
The Mu’tazila (e.g. ‘Abd al-Jabbar, d. 1025) held that the value of acts can generally be known by reason. The Ash’arites (al-Ash’ari, d. 935 or 936) disagreed. For them good and evil are fixed by God’s command and known through revelation. Avicenna, Averroes and Maimonides developed Aristotle within Islamic and Jewish law. Aquinas drew on them. He called Averroes ‘the Commentator’ and followed Avicenna and Maimonides on several questions.
Built on: Law from revelation; The Decalogue; Virtue is a habit
Led to: Natural law
Address: /trees/ethics?n=a-reason-revelation
Natural law (1265–1274 · Idea)
Aquinas’s Summa Theologiae argues that there is a law reason can discover. It binds all people, and human law should follow it. The idea joins Stoic and Roman thought, Aristotle, Christian doctrine, and the work of Islamic and Jewish philosophers such as Avicenna, Averroes and Maimonides, on whom Aquinas drew.
Built on: Live by reason and nature; Love your neighbour; Virtue is a habit; Reason or revelation?
Led to: Rights from nature
Source: Stanford Encyclopedia of Philosophy, ‘Aquinas’s Moral, Political, and Legal Philosophy’
Address: /trees/ethics?n=a-natlaw
Rights from nature (1689 · Idea)
Locke’s Second Treatise of Government holds that in the state of nature everyone has natural rights to life, liberty and property. Government exists to protect them. Natural rights give individuals claims that no ruler may override.
Built on: Natural law
Led to: Declaration of Human Rights
Source: Stanford Encyclopedia of Philosophy, ‘Locke’s Political Philosophy’
Address: /trees/ethics?n=a-locke
Without gods
Do no harm to any life (c. 6th–5th c. BC · Idea)
Jain teaching, linked to Mahavira, makes ahimsa the first duty. Ahimsa means avoiding harm to any living being. It extends to animals and plants. It’s one of the oldest rules whose circle of concern reaches beyond humans.
Built on: Shame the boaster
Led to: Many-sided truth
Source: Britannica, ‘Ahimsa’
Address: /trees/ethics?n=a-jain
Roles, ritual and humaneness (c. 500 BC · Idea)
The Analects, attributed to Confucius and his students, ground moral life in roles within family and state. Filial piety (xiao) is the root. Ritual (li) gives conduct its form. Ren, humaneness, is the quality of the exemplary person (junzi). Reciprocity (shu) gives a rule of restraint: do not do to others what you would not want done to yourself (Analects 15.24).
Built on: Shame the boaster
Led to: The Golden Rule; Declaration of Human Rights; Sprouts of goodness; Human nature is bad; Care without gradation
Source: Stanford Encyclopedia of Philosophy, ‘Confucius’
Address: /trees/ethics?n=a-confucius
The five precepts (c. 5th c. BC · Idea)
Buddhist lay practice includes five precepts. Refrain from killing, stealing, sexual misconduct, false speech and intoxicants. They’re framed as training rules a person takes on. They’re not commands from a deity.
Built on: Shame the boaster
Led to: The Golden Rule; Ashoka protects animals
The sources leave this date or claim uncertain.
Source: Stanford Encyclopedia of Philosophy, ‘Ethics in Indian and Tibetan Buddhism’
Address: /trees/ethics?n=a-buddha
No gods, no afterlife (Ajita: c. 5th century BC; Cārvāka school: attested only in later reports · Idea)
Ajita Kesakambalī is a teacher the Pali Sāmaññaphala Sutta (DN 2) places in the Buddha’s time. He is reported to have taught that there is no other world. Gifts and sacrifices bear no fruit. Fool and wise alike are cut off at death. The later Cārvāka or Lokāyata school is the Indian tradition best known for a thoroughgoing materialism with no gods. Its own texts are lost. We know it mostly from opponents, who describe its ethics as the pursuit of pleasure.
Source: Dīgha Nikāya 2 (Sāmaññaphala Sutta), Ajita Kesakambalī section; Britannica, ‘Carvaka’
Address: /trees/ethics?n=g-carvaka
Good because God says so? (c. 380 BC · Idea)
In Plato’s Euthyphro, Socrates asks a question. Do the gods love the pious because it is pious? Or is it pious because they love it? The question separates what is right from who commands it.
Built on: Hammurabi’s code
Source: Plato, Euthyphro (trans. Jowett), Project Gutenberg
Address: /trees/ethics?n=g-euthyphro
The Ring of Gyges (c. 375 BC · Idea)
In Republic Book II, Glaucon tells of a ring that makes its wearer invisible. He asks whether anyone would stay just if they could act without being seen or punished. It’s the oldest well-known test of conduct with no witnesses and no consequences.
Led to: Virtue is a habit; Live by reason and nature; Suppose you are the only one
Source: Plato, Republic, Book II (trans. Jowett), Project Gutenberg
Address: /trees/ethics?n=g-gyges
Virtue is a habit (c. 340 BC · Idea)
In the Nicomachean Ethics Aristotle argues that the good life is activity in line with virtue. Virtues of character are formed by habit. They’re judged against a mean between extremes. The question shifts from what is forbidden to what kind of person to become.
Built on: The Ring of Gyges
Led to: Natural law; Choose who you are; Reason or revelation?
Source: Stanford Encyclopedia of Philosophy, ‘Aristotle’s Ethics’
Address: /trees/ethics?n=a-aristotle
Sprouts of goodness (4th century BC · Idea)
Mencius held that human nature tends toward goodness. Everyone has the beginning ‘sprouts’ of compassion, shame, deference and approval and disapproval. Upbringing can nurture or stunt them. His argument is a child about to fall into a well. Anyone would respond with alarm and compassion, with no thought of reward or reputation (Mencius 2A6).
Built on: Roles, ritual and humaneness; Care without gradation
Led to: Human nature is bad
Source: Stanford Encyclopedia of Philosophy, ‘Mencius’; Mencius 2A6, 6A6
Address: /trees/ethics?n=g-mencius
Gods do not watch (c. 300 BC · Idea)
Epicurus taught that the gods exist but take no part in human affairs. So there is no divine judgement to fear. He taught that justice is an agreement not to harm one another. He held that wrongdoing is bad because you can’t be sure of escaping detection, or of peace of mind afterwards.
Led to: The is–ought gap; Count the consequences; The tedium of living forever
Source: Stanford Encyclopedia of Philosophy, ‘Epicurus’
Address: /trees/ethics?n=g-epicurus
Human nature is bad (3rd century BC · Idea)
Xunzi, also a follower of Confucius, held that ‘human nature is bad’ (ch. 23). Left alone, our desires breed strife, and goodness is something made. The sage kings established ritual and rules to reshape desire. He treated Heaven as the regular order of nature, which neither rewards nor punishes (ch. 17).
Built on: Roles, ritual and humaneness; Sprouts of goodness
Source: Stanford Encyclopedia of Philosophy, ‘Xunzi’
Address: /trees/ethics?n=g-xunzi
Many-sided truth (canonical roots; classical formulation c. 5th–8th century AD (dates uncertain) · Idea)
Jain anekantavada holds that reality has many aspects, so no single statement captures it. Syadvada puts syat (‘in some respect’) in front of each claim and sorts claims into seven forms. Later Jain philosophers, among them Siddhasena Divakara and Samantabhadra, developed it into a method. It weighs rival views without dismissing any outright.
Built on: Do no harm to any life
The sources leave this date or claim uncertain.
Address: /trees/ethics?n=g-anekanta
The is–ought gap (1739–1740 · Idea)
In A Treatise of Human Nature, Hume argued that moral distinctions come from sentiment, not from reason alone. He noted that writers move from statements of what is to statements of what ought to be, without explaining the step. Readers still argue about what he meant: that no such inference can ever be valid, or only that it needs a justification.
Built on: Gods do not watch
Led to: Conscience from instincts; Give yourself the law; Count the consequences; Identity is not what matters
Source: Stanford Encyclopedia of Philosophy, ‘Hume’s Moral Philosophy’
Address: /trees/ethics?n=g-hume
Give yourself the law (1785 · Idea)
Kant’s Groundwork argues that a rational person is bound by a law they give themselves. It’s tested in two ways. One is to ask whether you could will the rule for everyone. The other is the Humanity formula: treat humanity, in yourself and others, never merely as a means. The law needs no divine commander. But Kant held that the highest good, virtue matched by happiness, requires the postulates of God and immortality. He also held that our duties concerning animals are only indirect, owed to humanity.
Built on: The is–ought gap; Love your neighbour
Led to: Nothing above the self; The death of God; Choose without knowing; The veil of ignorance; Declaration of Human Rights; The Case for Animal Rights; Rules for synthetic minds; Animals as ends
Source: Stanford Encyclopedia of Philosophy, ‘Kant’s Moral Philosophy’
Address: /trees/ethics?n=g-kant
Count the consequences (1789–1861 · Idea)
Bentham (1789) and Mill (1861) held that right actions are those that produce the greatest happiness for the greatest number, with each person counted equally. The rule needs no god. It only needs a way to compare how lives go.
Built on: Gods do not watch; The is–ought gap
Led to: Humanist Manifestos; Choose without knowing; The experience machine; Can they suffer; Animal Liberation; Harm principle
Source: Stanford Encyclopedia of Philosophy, ‘The History of Utilitarianism’
Address: /trees/ethics?n=g-util
Nothing above the self (1844 · Idea)
Stirner’s The Ego and Its Own rejects every higher cause, including humanity and morality, as a fixed idea. It takes the individual’s own interest as the only ground. It’s the most thoroughgoing early statement that no rule stands above the person.
Built on: Give yourself the law
Source: Stanford Encyclopedia of Philosophy, ‘Max Stirner’
Address: /trees/ethics?n=g-stirner
Conscience from instincts (1871 · Idea)
In The Descent of Man, Darwin argued that the moral sense grew out of social instincts such as sympathy, joined to memory and reason. He argued it isn’t unique to humans in origin. This tied rules for behaviour to animal life without appeal to a lawgiver.
Built on: The is–ought gap
Led to: The death of God
Source: Darwin, The Descent of Man (1871), ch. 3–4, Project Gutenberg
Address: /trees/ethics?n=g-darwin
If there is no God (1880 · Idea)
In Dostoevsky’s The Brothers Karamazov, Ivan presses the question of what limits conduct if there is no immortality or God. The book is the source of the saying usually paraphrased as ‘everything is permitted’. The novel argues the question from several sides. It doesn’t give one answer.
Built on: Love your neighbour
Source: Dostoevsky, The Brothers Karamazov (1880), Project Gutenberg
Address: /trees/ethics?n=g-karamazov
The death of God (1882 · Idea)
In The Gay Science (section 125), Nietzsche’s madman announces that God is dead and that we have killed him. Section 341 poses eternal recurrence as a test: could you affirm your life as you’ve lived it? He treats the loss of a shared ground for values as an event. People must answer it by creating new values.
Built on: Love your neighbour; Give yourself the law; Conscience from instincts
Led to: Live without a given meaning; Existence before essence
Source: Stanford Encyclopedia of Philosophy, ‘Friedrich Nietzsche’
Address: /trees/ethics?n=g-nietzsche
Humanist Manifestos (1933, 1973, 2003)
Three Humanist Manifestos, issued in 1933, 1973 and 2003, state ethics without appeal to a supernatural source. They place values in human need and shared experience. Each revision widened its concerns. The later ones include animals and the environment.
Built on: Count the consequences
The sources leave this date or claim uncertain.
Source: American Humanist Association, ‘Humanist Manifesto I’
Address: /trees/ethics?n=g-humanist
Live without a given meaning (1942 · Idea)
In The Myth of Sisyphus, Camus argues that life has no given meaning. He calls the clash between the human demand for meaning and the silent world the absurd. He rejects suicide as an answer. He concludes that one can live with revolt, and without appeal to anything beyond the world.
Built on: The death of God
Led to: Existence before essence
Source: Stanford Encyclopedia of Philosophy, ‘Albert Camus’
Address: /trees/ethics?n=g-camus
Existence before essence (1945–1946 · Idea)
In ‘Existentialism is a Humanism’, delivered in 1945 and published in 1946, Sartre argues that there is no god to fix human nature. So each person makes themselves by their choices and answers for what they choose, because in choosing they choose for everyone. He holds that this is a burden, not a licence.
Built on: The death of God; Live without a given meaning
Led to: Choose who you are
Source: Stanford Encyclopedia of Philosophy, ‘Jean-Paul Sartre’
Address: /trees/ethics?n=g-sartre
Choose without knowing (1953–1955 · Idea)
Harsanyi argued that a rational, impartial chooser who doesn’t know which person they will be should pick the rules that maximise average well-being. His 1955 paper makes the case with an explicit model of choice behind such ignorance.
Built on: Count the consequences; Give yourself the law
Led to: The veil of ignorance
Address: /trees/ethics?n=g-harsanyi
The veil of ignorance (1971 · Idea)
In Rawls’s A Theory of Justice, people choose principles for society from an original position. In it they don’t know their class, talents or place in life. He argues they would choose equal basic liberties, and arrangements that most benefit the worst off.
Built on: Give yourself the law; Choose without knowing
Led to: Veil, all species; The experience machine; Identity is not what matters; Sharing with digital minds; Rules behind a wider veil; Capabilities for animals
Source: Stanford Encyclopedia of Philosophy, ‘The Original Position’
Address: /trees/ethics?n=g-rawls
Veil, all species (2007–2016 · Idea)
Several authors have asked what Rawlsian choosers would decide if they didn’t know which species they belonged to. Hilden (2007) argues that being a nonhuman animal is a matter of chance, so it belongs behind the veil. Liberto (2016) argues such choosers would end up nearer to utilitarianism than to Rawls’s own principles.
Built on: The veil of ignorance; Animal Liberation
Led to: Rules behind a wider veil
Address: /trees/ethics?n=g-veil-animals
Rules behind a wider veil (Open question)
If you might wake up as any being, what rules would you choose? That could be a human, an animal, a synthetic being or a character in a simulation. Choosers behind the veil can be asked to ignore their species. Buddhist writers such as Śāntideva ask us to weigh others’ suffering as our own. But no agreed account says what choosers should do about beings whose experience is uncertain or whose numbers can change.
Built on: The veil of ignorance; Veil, all species; Taking AI welfare seriously; Identity is not what matters
Closest published thinking:- Rawls (1971): Sets out choice of principles from an original position without knowledge of one’s place in society. A Theory of Justice, Harvard University Press
- Hilden (2007): Argues the possibility of being a non-human animal belongs behind the veil of ignorance. Animal Law 14
- Liberto (2016): Argues that representatives of all animals behind the veil would choose principles nearer utilitarian than Rawls’s. Utilitas
- Śāntideva (c. 700-750): Argues that no suffering belongs to anyone in the end and should be prevented simply as suffering, and asks the reader to exchange self and other so that others’ pain is felt as one’s own. Bodhicaryāvatāra, ch. 8 (verses 90–103 and the exchange meditation of 8.120–131)
Address: /trees/ethics?n=q-veil-all
Own experience
Choose who you are (1958–1984 · Idea)
Anscombe (1958) argued that the language of moral duty had lost its footing without a lawgiver. She pointed back to virtue and flourishing, and that revived virtue ethics. Read with Sartre, the question becomes what character you make for yourself.
Built on: Virtue is a habit; Existence before essence
Source: Anscombe, ‘Modern moral philosophy’, Philosophy 33 (1958) 1–19; SEP, ‘Virtue Ethics’
Address: /trees/ethics?n=x-virtue-back
The last person (1973 · Idea)
Routley asked whether the last person left alive would do wrong by destroying the rest of the living world. It’s a case of acting when no other person is affected. It tests whether any rule survives when no one is left whose interests are at stake.
Led to: Suppose you are the only one
Address: /trees/ethics?n=x-routley
The tedium of living forever (1973 · Idea)
Williams’s essay on the Makropulos case argues that an endless life would become unbearable, or would stop being your own. The desires that give a life its point would run out, or change beyond recognition. Many Indian traditions treat endless rebirth (samsara) as bondage and liberation as release. But a series of rebirths without memory isn’t the single continuing life Williams considers.
Built on: Gods do not watch
Source: Stanford Encyclopedia of Philosophy, ‘Bernard Williams’
Address: /trees/ethics?n=x-makropulos
The experience machine (1974 · Idea)
Nozick’s Anarchy, State, and Utopia asks whether you would plug into a machine that gives any experiences you choose. He argues most people wouldn’t. We want to do things and be a certain kind of person, not only to have experiences. The case is used against views on which only experiences matter.
Built on: Count the consequences; The veil of ignorance
Led to: Do virtual lives count; Choosing a virtual life
Source: Stanford Encyclopedia of Philosophy, ‘Hedonism’
Address: /trees/ethics?n=x-machine
Suppose you are the only one (hypothesis examined since antiquity · Idea)
Philosophers have examined solipsism, the view that only your own mind exists. They’ve mostly treated it as a puzzle about knowledge. They’ve also asked what ethics could mean if you were alone. The site doesn’t hold this view. It writes as though other people exist and matter. It appears here only as a hypothesis that has been examined.
Built on: The last person; The Ring of Gyges
The sources leave this date or claim uncertain.
Source: Stanford Encyclopedia of Philosophy, ‘Other Minds’
Address: /trees/ethics?n=x-alone
Identity is not what matters (1984 · Idea)
In Reasons and Persons, Parfit argues that personal identity is not what matters in survival. What matters is psychological connection and continuity. These can come in degrees and can be shared. That gives a new way to answer questions about copies, division and fusion of persons. Parfit himself noted the parallel with the Buddhist teaching that there is no enduring self. He cited Buddhist passages in an appendix.
Built on: The is–ought gap; The veil of ignorance
Led to: Do virtual lives count; Many bodies, one being; Rules behind a wider veil
Source: Stanford Encyclopedia of Philosophy, ‘Personal Identity’
Address: /trees/ethics?n=x-parfit
Do virtual lives count (2022 · Idea)
Chalmers’s Reality+ argues that virtual worlds are genuine realities and that a person can lead a meaningful life in one. The book also takes up what we owe to the characters in such worlds, if they are conscious.
Built on: The experience machine; Identity is not what matters
Led to: Choosing a virtual life; Rights from inside a simulation
Source: Chalmers, Reality+: Virtual Worlds and the Problems of Philosophy (W. W. Norton, 2022)
Address: /trees/ethics?n=x-chalmers
Many bodies, one being (Open question)
Do our rules apply to a being that lives and dies as many organisms at once? Most legal rules and many moral rules assume one body and one life. Relational and no-self traditions already treat persons differently. No settled account says how to count harm or consent for a being that is many bodies, copied minds, or a group that may itself be a subject.
Built on: Identity is not what matters; Sharing with digital minds; A defence of AI rights
Closest published thinking:- Parfit (1984): Argues that what matters in survival is psychological continuity, which can divide, merge and come in degrees. Reasons and Persons, Oxford University Press
- Shulman and Bostrom (2021): Considers digital minds that can be copied, merged and run in large numbers, and what that does to moral status and resource claims. Rethinking Moral Status, Oxford University Press, 306–326
- Schwitzgebel (2015): Argues that if materialism is true, some groups of people, such as a nation, are probably conscious subjects. Philosophical Studies 172, 1697–1721
Address: /trees/ethics?n=q-collective
Widening circle
Care without gradation (5th–4th century BC · Idea)
Mozi argued that disorder comes from partiality. He said people should show jian ai, usually translated ‘impartial’ or ‘inclusive’ care. It means concern for the welfare of others without ranking it by closeness. He tested customs, including elaborate Confucian funerals and music, by whether they benefit all. That makes his ethics an early consequence-based one.
Built on: Roles, ritual and humaneness
Led to: Sprouts of goodness
Source: Stanford Encyclopedia of Philosophy, ‘Mohism’
Address: /trees/ethics?n=c-mozi
Ashoka protects animals (c. 3rd century BC (Rock Edict I; Pillar Edict V in the king’s 26th regnal year))
In Rock Edict I, the Mauryan king Ashoka declares that no living being is to be slaughtered or offered in sacrifice in his domain. He says killing in his own kitchen is being cut to a few creatures. Pillar Edict V was issued twenty-six years after his coronation. It lists species declared protected, together with females with young and fish on set days.
Built on: The five precepts
Source: Dhammika (trans.), The Edicts of King Ashoka, Buddhist Publication Society (Wheel 386)
Address: /trees/ethics?n=c-ashoka
Can they suffer (1789 · Idea)
In a footnote to An Introduction to the Principles of Morals and Legislation, Bentham wrote that the question about animals is not whether they can reason or talk. It’s whether they can suffer. He used it to argue that the capacity to suffer, not species, sets who is owed consideration.
Built on: Count the consequences
Led to: Animal Liberation
Source: Stanford Encyclopedia of Philosophy, ‘The Moral Status of Animals’
Address: /trees/ethics?n=c-bentham
Declaration of Human Rights (1948)
The General Assembly of the United Nations adopted the Universal Declaration of Human Rights on 10 December 1948, by 48 votes to none with 8 abstentions. Article 1 says all human beings are born free and equal in dignity and rights and are endowed with reason and conscience. It was the first such statement adopted by the UN General Assembly. Its drafters came from several traditions. Chang Peng-chun, the Chinese delegate, proposed the word ‘conscience’ and drew on the Confucian idea of ren. Charles Malik, the Lebanese delegate, proposed ‘endowed with reason’.
Built on: Rights from nature; Give yourself the law; Roles, ritual and humaneness
Led to: The Expanding Circle
Source: United Nations, Universal Declaration of Human Rights (1948)
Address: /trees/ethics?n=c-udhr
Animal Liberation (1975 · Idea)
Singer’s Animal Liberation argues from equal consideration of interests that animals’ suffering counts. Treating it as less important because of species is a prejudice. It became a founding text of the modern animal protection movement.
Built on: Can they suffer; Count the consequences
Led to: Veil, all species; The Case for Animal Rights; The Expanding Circle; Wild lives have a value; Help wild animals; Capabilities for animals
Source: Stanford Encyclopedia of Philosophy, ‘The Moral Status of Animals’
Address: /trees/ethics?n=c-singer75
The Expanding Circle (1981 · Idea)
Singer’s The Expanding Circle argues that morality began as concern for kin and group. Reason has widened it to cover more beings. He ties the widening to evolved sympathy and to impartial reasoning.
Built on: Animal Liberation; Help your relatives; Declaration of Human Rights
Source: Singer, The Expanding Circle: Ethics and Sociobiology (Farrar, Straus and Giroux, 1981)
Address: /trees/ethics?n=c-circle81
The Case for Animal Rights (1983 · Idea)
Regan argued that animals who are subjects of a life have inherent value. They have rights that can’t be overridden for the sake of total benefit. His rights view is a rival to the utilitarian case for animals.
Built on: Animal Liberation; Give yourself the law
Led to: Dolphins as persons; Sandra the orangutan; A defence of AI rights
Source: Stanford Encyclopedia of Philosophy, ‘The Moral Status of Animals’
Address: /trees/ethics?n=c-regan
Capabilities for animals (2006 · Idea)
In Frontiers of Justice, Nussbaum argues that Rawls’s social contract is designed for roughly equal parties who gain from cooperating. So it can’t cover disabled people, foreigners, or non-human animals. Her capabilities approach asks what each creature needs to live a life worthy of its kind. She treats failing to provide it as an injustice, not only a lapse of compassion.
Built on: The veil of ignorance; Animal Liberation
Address: /trees/ethics?n=c-nussbaum
Cambridge Declaration (2012)
At a conference at Cambridge on 7 July 2012, neuroscientists signed a declaration. It says non-human animals have the neurological substrates of conscious states. That includes all mammals and birds and many other creatures, such as octopuses. Philip Low wrote it, and a group including Christof Koch edited it.
Led to: Dolphins as persons; Sandra the orangutan; Crabs and octopuses review; New York Declaration
Source: The Cambridge Declaration on Consciousness (2012)
Address: /trees/ethics?n=c-cambridge
Dolphins as persons (2013)
In May 2013 India’s environment ministry told state governments to reject proposals for dolphinaria. It said dolphins should be seen as non-human persons with their own rights, and that keeping them for entertainment is morally unacceptable. It was a policy statement, not a statute.
Built on: Cambridge Declaration; The Case for Animal Rights
Led to: Sanctuary or the wild
Source: Global Voices, ‘India sees dolphins as non-human persons’ (31 July 2013)
Address: /trees/ethics?n=c-india
Sandra the orangutan (2014–2019)
On 18 December 2014 an Argentine appeals court ruled on a habeas corpus petition for Sandra, an orangutan held in a Buenos Aires zoo. It called her a ‘non-human subject’ with rights, but it didn’t grant habeas corpus. A court ordered her moved to a sanctuary in 2015, and she moved to one in Florida in November 2019.
Built on: The Case for Animal Rights; Cambridge Declaration
Source: AP, ‘Orangutan granted “personhood” settles into new Florida home’ (7 November 2019)
Address: /trees/ethics?n=c-sandra
A defence of AI rights (2015 · Idea)
Schwitzgebel and Garza argue that artificial beings might come to have the psychological and social features that ground moral status in humans. If so, they would deserve similar rights. They also argue we should avoid building beings whose status is uncertain. They treat the issue as a live problem for design.
Built on: The Case for Animal Rights
Led to: Many bodies, one being; Pause synthetic suffering; Sharing with digital minds; Rights from inside a simulation
Address: /trees/ethics?n=c-schwitz-garza
A river as a legal person (2017)
New Zealand’s Te Awa Tupua (Whanganui River Claims Settlement) Act 2017 declared the Whanganui River a legal person. Two guardians speak for it. It’s a Treaty settlement with the Whanganui iwi. It reflects a Māori view of the river as an ancestor.
Source: Te Awa Tupua (Whanganui River Claims Settlement) Act 2017 (New Zealand)
Address: /trees/ethics?n=c-whanganui
Animals as ends (2018 · Idea)
Korsgaard’s Fellow Creatures argues, from Kantian premises, that animals are ends in themselves. We can’t count our own good as mattering without counting the good of any creature for which things can go well or badly. She rejects Kant’s own view that duties concerning animals are only indirect.
Built on: Give yourself the law
Address: /trees/ethics?n=c-korsgaard
Crabs and octopuses review (2021)
A review led by Jonathan Birch for the UK government looked at more than 300 studies. It recommended treating cephalopod molluscs and decapod crustaceans as sentient for the purposes of welfare law. It set out eight criteria for judging the evidence of sentience in an animal.
Built on: Cambridge Declaration
Led to: The UK’s Animal Welfare (Sentience) Act 2022; Pause synthetic suffering; New York Declaration
Address: /trees/ethics?n=c-birch
Pause synthetic suffering (2021 · Idea)
Metzinger (2021) proposed a global moratorium until 2050 on research that aims at, or risks, creating artificial consciousness. His worry is a possible explosion of negative experience in synthetic beings. A 2024 critique by Krzanowski argued that the moratorium is unsound as stated.
Built on: Crabs and octopuses review; A defence of AI rights
Led to: Indicators of AI awareness
Address: /trees/ethics?n=c-metzinger
Sharing with digital minds (2021 · Idea)
Shulman and Bostrom argue that moral norms built on assumptions about human life may not fit digital minds. Digital minds can be copied or sped up, or can have unusually strong claims on resources. They call for reform of norms and institutions. They also call for planning about which digital minds to create.
Built on: A defence of AI rights; The veil of ignorance
Led to: Many bodies, one being; Taking AI welfare seriously; Rules for synthetic minds; Rights from inside a simulation
Address: /trees/ethics?n=c-shulman
The UK’s Animal Welfare (Sentience) Act 2022 (2022)
The Act, passed in 2022, set up an Animal Sentience Committee. The committee reports on whether government policy has had due regard to animal welfare. The Act defines animals to include vertebrates, cephalopod molluscs and decapod crustaceans. Invertebrates were added to the Bill after the 2021 review. The Secretary of State may extend the list by regulation.
Built on: Crabs and octopuses review
Source: Animal Welfare (Sentience) Act 2022, c. 22 (UK)
Address: /trees/ethics?n=c-sentience-act
Indicators of AI awareness (2023)
Butlin, Long and colleagues drew indicator properties from scientific theories of consciousness. They checked existing AI systems against them. They concluded that no current system is a strong candidate. They saw no obvious barriers to building systems that meet the indicators.
Built on: Pause synthetic suffering
Led to: Taking AI welfare seriously
Address: /trees/ethics?n=c-butlin
New York Declaration (2024)
The declaration was launched at New York University on 19 April 2024. It says there is strong scientific support for conscious experience in mammals and birds. It says there is at least a realistic possibility of it in all vertebrates and many invertebrates, including insects. It says that ignoring this possibility in decisions that affect animals is irresponsible.
Built on: Cambridge Declaration; Crabs and octopuses review
Led to: Taking AI welfare seriously
The sources leave this date or claim uncertain.
Source: The New York Declaration on Animal Consciousness (2024)
Address: /trees/ethics?n=c-ny-declaration
Taking AI welfare seriously (2024 · Idea)
Long, Sebo and colleagues argue there is a realistic possibility that some AI systems will be conscious, or robustly agentic, in the near future. They recommend acknowledging the issue, assessing systems for signs, and preparing policies. They don’t claim that any system now has moral significance.
Built on: Indicators of AI awareness; Sharing with digital minds; New York Declaration
Led to: Rules for synthetic minds; Rules behind a wider veil
Source: Long, Sebo et al., ‘Taking AI welfare seriously’, arXiv:2411.00986 (2024)
Address: /trees/ethics?n=c-long
Rules for synthetic minds (Open question)
Should the hard-won rules that keep human societies together be extended to synthetic minds? And which ones? Rules against cheating, for fair shares and for peace-making grew up among beings who are mortal, similar to one another and costly to copy. It isn’t settled which of them depend on those conditions.
Built on: Taking AI welfare seriously; Sharing with digital minds; Police the egg-layers; Shame the boaster; Give yourself the law
Closest published thinking:- Shulman and Bostrom (2021): Argues that norms built on human assumptions may need reform when minds can be copied and have unusual claims on resources. Rethinking Moral Status, Oxford University Press
- Long, Sebo and colleagues (2024): Recommends assessing AI systems for consciousness and agency and preparing policies for how they are treated. arXiv:2411.00986
- Schwitzgebel and Garza (2015): Argues that artificial beings with the relevant features would deserve similar rights, and that design should take that into account. Midwest Studies in Philosophy 39
Address: /trees/ethics?n=q-cohesion
Rights from inside a simulation (Open question)
If we’re living in a simulation, our minds run on someone else’s computer, which makes us artificial minds of a kind. So any argument that denies rights to a mind just because it runs on a computer would deny them to us too. Arguments that ask whether a system really feels anything wouldn’t. Which kind is being made matters.
Built on: A defence of AI rights; Sharing with digital minds; Do virtual lives count
Closest published thinking:- Bostrom (2003): Argues that at least one of three propositions is true, one of them being that we are almost certainly living in a computer simulation. Philosophical Quarterly 53 (211)
- Schwitzgebel and Garza (2015): Argues that artificial beings with the relevant features would deserve similar rights, and that design should take that into account. Midwest Studies in Philosophy 39
- Chalmers (2022): Argues that virtual worlds are genuine realities and that beings in them can be conscious, and asks what we owe to such beings. Reality+, W. W. Norton
Address: /trees/ethics?n=q-own-rights
Cost of protection
The seabird feast (4th–2nd century BC (outer chapter 18; inner chapters are earlier) · Idea)
In Zhuangzi ch. 18, the Marquis of Lu welcomes a seabird to his ancestral temple with wine, music and the meat of an ox. It dies in three days. The point is that treating another creature by what would please you can kill it. The creature’s own way of living is the standard of its good.
Led to: Choosing a virtual life
Source: Zhuangzi, ch. 18 (‘Supreme Happiness’); Stanford Encyclopedia of Philosophy, ‘Zhuangzi’
Address: /trees/ethics?n=p-seabird
Harm principle (1859 · Idea)
In On Liberty, Mill argued that power may be used against a person’s will only to prevent harm to others. A person’s own good is not enough reason. He allowed stopping someone from crossing an unsafe bridge, as a case of not knowing the danger.
Built on: Count the consequences
Led to: Paternalism; The right to choose a risk; Choosing a virtual life
Source: Mill, On Liberty (1859), Project Gutenberg; SEP, ‘John Stuart Mill’
Address: /trees/ethics?n=p-mill
Paternalism (1972 · Idea)
Dworkin’s essay sets out when interfering with a person’s liberty for their own good could be justified. He proposes that it can be justified where people would consent to it as rational persons. The paper helped define the field of debate on paternalism.
Built on: Harm principle
Led to: The right to choose a risk; Choosing a virtual life
Source: Dworkin, ‘Paternalism’, The Monist 56 (1972) 64–84; SEP, ‘Paternalism’
Address: /trees/ethics?n=p-dworkin
Wild lives have a value (1980–1984 · Idea)
Callicott (1980) and Sagoff (1984) argued that caring about each animal’s welfare, taken consistently, would call for ending predation. That would destroy the wild communities that environmental ethics values. They concluded that animal liberation and environmental ethics can’t share one theory.
Built on: Animal Liberation
Led to: Help wild animals; Rewilding
Source: Callicott, ‘Animal liberation: a triangular affair’, Environmental Ethics 2 (1980) 311–338
Address: /trees/ethics?n=p-callicott
Rewilding (1998 · Idea)
Soule and Noss (1998) proposed rewilding. It means restoring large protected cores, linking corridors and top predators across a continent so that wild nature can run itself. The approach asks humans to step back and accept the harm that wild life contains.
Built on: Wild lives have a value
Address: /trees/ethics?n=p-rewild
Help wild animals (2010 · Idea)
Horta (2010) argued that wild animals suffer from hunger, disease and predation. So an approach that counts their interests should aim to reduce that harm, not keep ecosystems as they are. He gave wolf reintroduction as a case where the two goals conflict.
Built on: Animal Liberation; Wild lives have a value
Address: /trees/ethics?n=p-horta
Sanctuary or the wild (2013–2015)
India’s 2013 dolphinarium policy and the Argentine court order moving Sandra to a sanctuary both treat captivity as a cost to the animal. Both swap one form of protected life for another. Neither says whether a sanctuary is as good for the animal as freedom.
Built on: Dolphins as persons
Led to: Choosing a virtual life
The sources leave this date or claim uncertain.
Source: AP, ‘Orangutan granted “personhood” settles into new Florida home’ (7 November 2019)
Address: /trees/ethics?n=p-captive
The right to choose a risk (2015)
In Carter v Canada (2015), the Supreme Court of Canada held unanimously that the ban on assisted dying infringed the right to life, liberty and security of the person. That applied to competent adults suffering intolerably. It protects a competent adult’s choice of a medically assisted death, for a grievous and irremediable condition and within strict safeguards. The ruling took effect in 2016.
Built on: Harm principle; Paternalism
Led to: Choosing a virtual life
Source: Carter v. Canada (Attorney General), 2015 SCC 5
Address: /trees/ethics?n=p-carter
Choosing a virtual life (Open question)
If someone chooses to live as another kind of being in a simulation, do our protections respect that choice, or stand in its way? The same rules that shield people from harm they can’t see are used to override choices they’ve made. The rules give no clear test for which case a chosen virtual life is.
Built on: The experience machine; Do virtual lives count; Harm principle; Paternalism; The right to choose a risk; Sanctuary or the wild; The seabird feast
Closest published thinking:- Nozick (1974): Argues that most people would refuse a machine that supplies chosen experiences, since we want to be and do, not only to feel. Anarchy, State, and Utopia, Basic Books
- Chalmers (2022): Argues that virtual worlds are genuine realities and that a person can lead a meaningful life in one. Reality+, W. W. Norton
- Mill (1859): Allows interference only to prevent harm to others, with a narrow case for warning of danger the person does not know. On Liberty, ch. 1 and 5
Address: /trees/ethics?n=q-choose-being