QuestionsDo animals matter as much as we do?All beings love life and shun pain
Do animals matter as much as we do?Their suffering counts equally

All beings love life and shun pain

Ahimsa (non-violence) in Jainism

Mahāvīra (enseignement recueilli dans l'Ācārāṅga Sūtra) c. 599 BC · c. 527 BCAll beings love life and hate pain: no being that feels may be slain or tormented (ahimsa).
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What it claims

No breathing, existing, living, sentient being should be slain, treated with violence, abused, tormented or driven away, whatever its form.

Why

Every being that feels loves life and shuns pain as I do: what I do not want to suffer, it does not want either, whatever its form.

The same idea through history
Mahāvīra (enseignement recueilli dans l'Ācārāṅga Sūtra)400 BCThe Acaranga is the oldest book of the Jain canon. Tradition traces it to Mahavira (traditionally 599-527 BCE; historians rather place him in the 5th century), whose words were passed on by his disciples; the canon was only fixed in writing in the 5th century CE. The year -400 is a round value for the oldest part (book I), which scholars most often date to the 4th-3rd century BCE.
In short

"All beings love life and shun pain" is an argument by Mahāvīra (enseignement recueilli dans l'Ācārāṅga Sūtra) (Acaranga Sutra, I, 2, 3; I, 4, 1; I, 5, 5, 400 BC) on the question "Do animals matter as much as we do?" (answer: their suffering counts equally). Its claim: No breathing, existing, living, sentient being should be slain, treated with violence, abused, tormented or driven away, whatever its form. According to AskPhilosophy's logic check (Z3 solver), the argument is valid only if one grants a premise the author leaves unstated (P3). AskPhilosophy presents 3 objections, 3 of them with a documented reply, and the original text behind each premise, checked word for word.

Acaranga Sutra, I, 2, 3; I, 4, 1; I, 5, 5
Valid with an implicit premise

The Jains of India make non-violence (ahimsa) the first rule of life. In the Acaranga Sutra, the oldest book of their canon, the reasoning is simple. All living beings, says the text, love life, like pleasure and hate pain. So what I would inflict on another, I would inflict on a being who lives it as I do: "as it would be unto thee, so it is with him whom thou intendest to kill". The rule holds for all beings that breathe and feel, human or animal, without exception; the text even counts plants and beings of earth, water, fire and wind among the living. The text even lists the reasons people kill animals (sacrifice, skin, flesh, blood) and judges them all wrong. This argument is attributed to Mahavira (traditionally 599-527 BCE, rather the 5th century for historians), but the book is not in his hand: it was passed on orally and written down later. We quote Jacobi's English translation (1884), which is in the public domain.

P1All living beings are fond of life, like pleasure, hate pain, shun destruction and long to live. To all, life is dear.
P2What happens to the other is for it what it would be for me: to kill, tyrannise or torment a being is to do to it what I would not want to suffer.
P3 · implicit premiseThe form of the body (human, animal, insect) changes nothing about what pain and death are for the one who lives them: it gives no reason to count them for less.
P4One must not do to others what one would not want to suffer. The law forbidding to kill, strike or torment living beings is "pure, unchangeable, eternal": it is proclaimed for all, faithful or not, cruel or not.
So no breathing, existing, living, sentient being should be slain, treated with violence, abused, tormented or driven away, whatever its form.

click a premise to reject it

If you accept every premise, logic forces you to accept the conclusion. So the debate is about the premises.
Checked by a logic solver: the premises cannot all be true while the conclusion is false.
Without the implicit premise: Without P3, the computer finds a case where a being feels pain and loves life, where tormenting it is what I would not want to suffer, and where it may still be tormented, because it belongs to another species and that would count for less.
The argument is valid with the hidden premise P3. If all sentient beings want to live and shun pain (P1), if their suffering is for them what mine is for me (P2), if the form of the body changes nothing about it (P3), and if one must not impose on others what one would not want to suffer (P4), then one must harm no sentient being. The objections target P1 (do animals really feel?) and the conclusion (does the duty really cover animals?).
Analogy. Two people burn a finger. One speaks your language, the other does not. For Jainism the pain is the same for both, and it must not be inflicted on the second because she cannot complain in your language.

Objections

3

Each objection is a conversation: click to see who replies and where the debate stands.

René Descartes 1637 · attacks premise 1

For Descartes, animals have neither reason nor language. Their acts are explained by the arrangement of their organs, like a clock that tells the time without thinking. They would be machines, and many readers conclude that they do not feel pain as we do: there would be no one to love life or to suffer.

a defender replies
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Jeremy Bentham defender of the argument · 1789
Bentham answers that the question is not "Can they reason?" nor "Can they talk?" but "Can they suffer?". Many animals react to pain as we do, and what counts is their capacity to suffer, not their intelligence.
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Where the debate stands (our summary)Our summary: Descartes's objection is now very much a minority view in science. The present disagreement is rather about which animals feel (insects, fish) and how much that feeling matters.
Immanuel Kant 1780 · attacks the conclusion

For Kant, our duties concern rational beings. We must not be cruel to animals, but only because cruelty makes us hard toward humans. The duty therefore does not concern the animal itself.

a defender replies
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Arthur Schopenhauer defender of the argument · 1840
Schopenhauer finds "revolting" the doctrine that we have no duties toward animals. For him compassion is the only truly moral motive and it extends to all suffering, including that of animals, whom the other European systems leave unprotected.
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T
The Laws of Manu (Brahmanical tradition) 100 · attacks the conclusion

The Laws of Manu, a Brahmanical text from the same India, say the opposite for sacrifice: the Creator himself made animals for sacrifices, and sacrifice is instituted for the good of the world. Killing for a sacrifice is therefore not "slaughtering" in the ordinary sense.

a defender replies
T
The Acaranga Sutra (same book I) defender of the argument · 400 BC
The Jain text answers in advance: among the reasons people kill animals it lists sacrifices, skin, flesh and blood. He who injures them "does not comprehend" sin and does not renounce it; the wise man does not harm animals nor cause others to do so.
Where the debate stands (our summary)Our summary: this is a basic disagreement between two Indian traditions, not settled by proof. The Jains refuse that ritual justifies killing; the Brahmanical texts accept sacrifice, but limit violence elsewhere.