Richard A. Posneris a judge of the U.S. Court of Appeals for the 7th Circuit and a senior lecturer at the University of Chicago Law School. Peter Singer is the Ira W. DeCamp Professor of Bioethics at Princeton University. He is the author of, among other books, Animal Liberation. This week they discuss what, if any, ethical obligations humans have to animals.
Dear Judge Posner,
I'm not a lawyer, let alone a judge, but I've noticed increasing interest in legal circles in the topic of the legal status of animals. This seems to have been triggered in part by the efforts of the Great Ape Project, by the publication of Steven Wise's Rattling the Cage, and by the fact several law schools, including Harvard, are now teaching courses on law and animals. You reviewed Rattling the Cage in the Yale Law Journal, and while you were critical of Wise's argument that the law should recognize chimpanzees and other great apes as legal persons, your tone was respectful, and you took his argument seriously. That has encouraged me to attempt to persuade you that—for I am an ethicist, not a lawyer—there is a sound ethical case for changing the status of animals.
Before the rise of the modern animal movement there were societies for the prevention of cruelty to animals, but these organizations largely accepted that the welfare of nonhuman animals deserves protection only when human interests are not at stake. Human beings were seen as quite distinct from, and infinitely superior to, all forms of animal life. If our interests conflict with theirs, it is always their interests which have to give way. In contrast with this approach, the view that I want to defend puts human and nonhuman animals, as such, on the same moral footing. That is the sense in which I argued, in Animal Liberation, that "all animals are equal." But to avoid common misunderstandings, I need to be careful to spell out exactly what I mean by this. Obviously nonhuman animals cannot have equal rights to vote and nor should they be held criminally responsible for what they do. That is not the kind of equality I want to extend to nonhuman animals. The fundamental form of equality is equal consideration of interests, and it is this that we should extend beyond the boundaries of our own species. Essentially this means that if an animal feels pain, the pain matters as much as it does when a human feels pain—if the pains hurt just as much. How bad pain and suffering are does not depend on the species of being that experiences it.
People often say, without much thought, that all human beings are infinitely more valuable than any animals of any other species. This view owes more to our own selfish interests and to ancient religious teachings that reflect these interests than to reason or impartial moral reflection. What ethically significant feature can there be that all human beings but no nonhuman animals possess? We like to distinguish ourselves from animals by saying that only humans are rational, can use language, are self-aware, or are autonomous. But these abilities, significant as they are, do not enable us to draw the requisite line between all humans and nonhuman animals. For there are many humans who are not rational, self-aware, or autonomous, and who have no language—all humans under 3 months of age, for a start. And even if they are excluded, on the grounds that they have the potential to develop these capacities, there are other human beings who do not have this potential. Sadly, some humans are born with brain damage so severe that they will never be able to reason, see themselves as an independent being, existing over time, make their own decisions, or learn any form of language.
If it would be absurd to give animals the right to vote, it would be no less absurd to give that right to infants or to severely retarded human beings. Yet we still give equal consideration to their interests. We don't raise them for food in overcrowded sheds or test household cleaners on them. Nor should we. But we do these things to nonhuman animals who show greater abilities in reasoning than these humans. This is because we have a prejudice in favor of the view that all humans are somehow infinitely more valuable than any animal. Sadly, such prejudices are not unusual. Like racists and sexists, speciesists say that the boundary of their own group is also a boundary that marks off the most valuable beings from all the rest. Never mind what you are like, if you are a member of my group, you are superior to all those who are not members of my group. The speciesist favors a larger group than the racist and so has a large circle of concern; but all these prejudices use an arbitrary and morally irrelevant fact—membership of a race, sex, or species—as if it were morally crucial. The only acceptable limit to our moral concern is the point at which there is no awareness of pain or pleasure, and no preferences of any kind. That is why pigs count, but lettuces don't. Pigs can feel pain and pleasure. Lettuces can't.
One closing caution: I have been arguing against the widely accepted idea that we are justified in discounting the interests of an animal merely because it is not a member of the species Homo sapiens. I have not argued against the more limited claim that there is something special about beings with the mental abilities that normal humans possess, once they are past infancy, and that when it is a question of life or death, we are justified in giving greater weight to saving their lives. Of course, some humans do not possess these mental abilities, and arguably some nonhuman animals do—here we return to the chimpanzees and other great apes with which I began. But whatever we decide about the value of a life, this is a separate issue from our decisions about practices that inflict suffering. Unfortunately a great deal of what Americans do to animals, especially in raising them for food in modern industrialized farms, does inflict prolonged suffering on literally billions of animals each year. Since we can live very good lives without doing this, it is wrong for us to inflict this suffering, irrespective of the question of the wrongness of taking the lives of these animals.