Let me tell you about the worst thing I have ever done. In 1975, as a twenty-year-old sophomore, I got a summer job as a research assistant in an animal behavior lab. One evening the professor gave me an assignment. Among the rats in the lab was a runt that could not participate in the ongoing studies, so he wanted to use it to try out a new experiment. The first step was to train the rat in what was called a temporal avoidance conditioning procedure. The floor of a Skinner box was hooked up to a shock generator, and a timer that would shock the animal every six seconds unless it pressed a lever, which would give it a ten-second reprieve. Rats catch on quickly and press the lever every eight or nine seconds, postponing the shock indefinitely. All I had to do was throw the rat in the box, start the timers, and go home for the night. When I arrived back at the lab early the next morning, I would find a fully conditioned rat.

But that was not what looked back at me when I opened the box in the morning. The rat had a grotesque crook in its spine and was shivering uncontrollably. Within a few seconds, it jumped with a start. It was nowhere near the lever. I realized that the rat had not learned to press the lever and had spent the night being shocked every six seconds. When I reached in to rescue it, I found it cold to the touch. I rushed it to the veterinarian two floors down, but it was too late, and the rat died an hour later. I had tortured an animal to death.

The resonance with certain episodes of 20th-century history is too close for comfort, and in the next chapter I will expand on the psychological lesson I learned that day. The reason I bring up this blot on my conscience is to show what was standard practice in the treatment of animals at the time. To motivate the animals to work for food, we starved them to 80 percent of their freefeeding weight, which in a small animal means a state of gnawing hunger. In the lab next door, pigeons were shocked through beaded keychains that were fastened around the base of their wings; I saw that the chains had worn right through their skin, exposing the muscle below. In another lab, rats were shocked through safety pins that pierced the skin of their chests. In one experiment on endorphins, animals were given unavoidable shocks described in the paper as "extremely intense, just subtetanizing"-- that is, just short of the point where the animal's muscles would seize up in a state of tetanus. The callousness extended outside the testing chambers. One researcher was known to show his anger by picking up the nearest unused rat and throwing it against a wall. Another shared a cold joke with me: a photograph, printed in a scientific journal, of a rat that had learned to avoid shocks by lying on its furry back while pressing the food lever with its forepaw. The caption: "Breakfast in bed."

As the experiment was being explained to me, I had already sensed it was wrong. Even if the procedure had gone perfectly, the rat would have spent twelve hours in constant anxiety, and I had enough experience to know that laboratory procedures don't always go perfectly. My professor was a radical behaviorist, for whom the question "What is it like to be a rat?" was simply incoherent. But I was not, and there was no doubt in my mind that a rat could feel pain. The professor wanted me in his lab; I knew that if I refused, nothing bad would happen. But I carried out the procedure anyway, reassured by the ethically spurious but psychologically reassuring principle that it was standard practice.

I'm relieved to say that just five years later, indifference to the welfare of animals among scientists had become unthinkable, indeed illegal. Beginning in the 1980s, any use of an animal for research or teaching had to be approved by an Institutional Animal Care and Use Committee (IACUC), and any scientist will confirm that these committees are not rubber stamps. The size of cages, the amount and quality of food and veterinary care, and the opportunities for exercise and social contact are strictly regulated. Researchers and their assistants must take a training course on the ethics of animal experimentation, attend a series of panel discussions, and pass an exam. Any experiment that would subject an animal to discomfort or distress is placed in a category governed by special regulations and must be justified by its likelihood of providing "a greater benefit to science and human welfare."

Any scientist will also confirm that attitudes among scientists themselves have changed. Recent surveys have shown that animal researchers, virtually without exception, believe that laboratory animals feel pain. Today a scientist who was indifferent to the welfare of laboratory animals would be treated by his or her peers with contempt.

The change in the treatment of laboratory animals is part of yet another rights revolution: the growing conviction that animals should not be subjected to unjustifiable pain, injury, and death. The revolution in animal rights is a uniquely emblematic instance of the decline of violence, and it is fitting that I end my survey of historical declines by recounting it. That is because the change has been driven purely by the ethical principle that one ought not to inflict suffering on a sentient being. Unlike the other Rights Revolutions, the movement for animal rights was not advanced by the affected parties themselves: the rats and pigeons were hardly in a position to press their case. Nor has it been a by-product of commerce, reciprocity, or any other positive-sum negotiation; the animals have nothing to offer us in exchange for our treating them more humanely. And unlike the revolution in children's rights, it does not hold out the promise of an improvement in the makeup of its beneficiaries later in life. The recognition of animal interests was taken forward by human advocates on their behalf, who were moved by empathy, reason, and the inspiration of the other Rights Revolutions. Progress has been uneven, and certainly the animals themselves, if they could be asked, would not allow us to congratulate ourselves too heartily just yet. But the trends are real, and they are touching every aspect of our relationship with our fellow animals.

When we think of indifference to animal welfare, we tend to conjure up images of scientific laboratories and factory farms. But callousness toward animals is by no means modern. In the course of human history it has been the default.

Killing animals to eat their flesh is a part of the human condition. Our ancestors have been hunting, butchering, and probably cooking meat for at least two million years, and our mouths, teeth, and digestive tracts are specialized for a diet that includes meat. The fatty acids and complete protein in meat enabled the evolution of our metabolically expensive brains, and the availability of meat contributed to the evolution of human sociality. The jackpot of a felled animal gave our ancestors something of value to share or trade and set the stage for reciprocity and cooperation, because a lucky hunter with more meat than he could consume on the spot had a reason to share it, with the expectation that he would be the beneficiary when fortunes reversed. And the complementary contributions of hunted meat from men and gathered plants from women created synergies that bonded men and women for reasons other than the obvious ones. Meat also provided men with an efficient way to invest in their offspring, further strengthening family ties.

The ecological importance of meat over evolutionary time left its mark in the psychological importance of meat in human lives. Meat tastes good, and eating it makes people happy. Many traditional cultures have a word for meat hunger, and the arrival of a hunter with a carcass was an occasion for village-wide rejoicing. Successful hunters are esteemed and have better sex lives, sometimes by dint of their prestige, sometimes by explicit exchanges of the carnal for the carnal. And in most cultures, a meal does not count as a feast unless meat is served.

With meat so important in human affairs, it's not surprising that the welfare of the entities whose bodies provide that meat has been low on the list of human priorities. The usual signals that mitigate violence among humans are mostly absent in animals: they are not close kin, they can't trade favors with us, and in most species they don't have faces or expressions that elicit our sympathy. Conservationists are often exasperated that people care only about the charismatic mammals lucky enough to have faces to which humans respond, like grinning dolphins, sad-eyed pandas, and baby-faced juvenile seals. Ugly species are on their own.

ROAST TURTLE

Ingredients:

The reverence for nature commonly attributed to foraging people in children's books did not prevent them from hunting large animals to extinction or treating captive animals with cruelty. Hopi children, for example, were encouraged to capture birds and play with them by breaking their legs or pulling off their wings. A Web site for Native American cuisine includes the following recipe:

One turtle

Directions:

One campfire

When you hear the shell crack, he's done.

The cutting or cooking of live animals by traditional peoples is far from uncommon. The Masai regularly bleed their cattle and mix the blood with milk for a delicious beverage, and Asian nomads cut chunks of fat from the tails of living sheep that they have specially bred for that purpose. Pets too are treated harshly: a recent cross-cultural survey found that half the traditional cultures that keep dogs as pets kill them, usually for food, and more than half abuse them. Among the Mbuti of Africa, for example, "the hunting dogs, valuable as they are, get kicked around mercilessly from the day they are born to the day they die." When I asked an anthropologist friend about the treatment of animals by the hunter-gatherers she had worked with, she replied:

Put a turtle on his back on the fire.

The early civilizations that depended on domesticated livestock often had elaborate moral codes on the treatment of animals, but the benefits to the animal were mixed at best. The overriding principle was that animals exist for the benefit of humans. In the Hebrew Bible, God's first words to Adam and Eve in Genesis 1:28 are "Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth." Though Adam and Eve were frugivores, after the flood the human diet switched to meat. God told Noah in Genesis 9:2-3: "The fear of you and the dread of you shall be upon every beast of the earth, and upon every fowl of the air, upon all that moveth upon the earth, and upon all the fishes of the sea; into your hand are they delivered. Every moving thing that liveth shall be meat for you; even as the green herb have I given you all things." Until the destruction of the second temple by the Romans in 70 CE, vast numbers of animals were slaughtered by Hebrew priests, not to nourish the people but to indulge the superstition that God had to be periodically placated with a well-done steak. (The smell of charbroiled beef, according to the Bible, is "a soothing aroma" and "a sweet savor" to God.)

That is perhaps the hardest part of being an anthropologist. They sensed my weakness and would sell me all kinds of baby animals with descriptions of what they would do to them otherwise. I used to take them far into the desert and release them, they would track them, and bring them back to me for sale again!

Ancient Greece and Rome had a similar view of the place of animals in the scheme of things. Aristotle wrote that "plants are created for the sake of animals, and the animals for the sake of man." Greek scientists put this attitude into practice by dissecting live mammals, including, occasionally, Homo sapiens. (According to the Roman medical writer Celsus, physicians in Hellenic Alexandria "procured criminals out of prison by royal permission, and dissecting them alive, contemplated, while they were yet breathing, the parts which nature had before concealed.") The Roman anatomist Galen wrote that he preferred to work with pigs rather than monkeys because of the "unpleasant expression" on the monkeys' faces when he cut into them. His compatriots, of course, delighted in the torture and slaughter of animals in the Colosseum, again not excluding a certain bipedal primate. In Christendom, Saints Augustine and Thomas Aquinas combined biblical with Greek views to ratify the amoral treatment of animals. Aquinas wrote, "By the divine providence [animals] are intended for man's use… Hence it is not wrong for man to make use of them, either by killing or in any other way whatsoever."

When it came to the treatment of animals, modern philosophy got off to a bad start. Descartes wrote that animals were clockwork, so there was no one home to feel pain or pleasure. What sound to us like cries of distress were merely the output of a noisemaker, like a warning buzzer on a machine. Descartes knew that the nervous systems of animals and humans were similar, so from our perspective it's odd that he could grant consciousness to humans while denying it to animals. But Descartes was committed to the existence of the soul, granted to humans by God, and the soul was the locus of consciousness. When he introspected on his own consciousness, he wrote, he could not "distinguish in myself any parts, but apprehend myself to be clearly one and entire… The faculties of willing, feeling, conceiving, etc. cannot be properly speaking said to be its parts, for it is one and the same mind which employs itself in willing and in feeling and understanding." Language too is a faculty of this indivisible thing we call mind or soul. Since animals lack language, they must lack souls; hence they must be without consciousness. A human has a clockwork body and brain, like an animal, but also a soul, which interacts with the brain through a special structure, the pineal gland.

From the standpoint of modern neuroscience, the argument is loopy. Today we know that consciousness depends, down to the last glimmer and itch, on the physiological activity of the brain. We also know that language can be dissociated from the rest of consciousness, most obviously in stroke patients who have lost their ability to speak but have not been turned into insensate robots. But aphasia would not be documented until 1861 (by Descartes' compatriot Paul Broca), and the theory sounded plausible enough at the time. For centuries live animals would be dissected in medical laboratories, encouraged by the church's disapproval of the dissection of human cadavers. Scientists cut the limbs off living animals to see if they would regenerate, drew out their bowels, pulled off their skin, and removed their organs, including their eyes.

Agriculture was no more humane. Practices like gelding, branding, piercing, and the docking of ears and tails have been common in farms for centuries. And cruel practices to fatten animals or tenderize their meat (familiar to us today from protests against foie gras and milk-fed veal) are by no means a modern invention. A history of the British kitchen describes some of the methods of tenderization in the 17th century:

Poultry, in order to put on flesh after its long journey from the farms, was sewn up by the gut… turkey were bled to death by hanging them upside down with a small incision in the vein of the mouth; geese were nailed to the floor; salmon and carp were hacked into collops while living to make their flesh firmer; eels were skinned alive, coiled around skewers and fixed through the eye so they could not move… The flesh of the bull, it was believed, was indigestible and unwholesome if the animal was killed without being baited… Calves and pigs were whipped to death with knotted ropes to make the meat more tender, rather than our modern practice of beating the flesh when dead. "Take a red cock that is not too old and beat him to death," begins one… recipe.

The Elizabethan method of "brawning" or fattening pigs was "to keep them in so close a room that they cannot turn themselves round about… whereby they are forced always to lie on their bellies." "They feed in pain," said a contemporary, "lie in pain and sleep in pain." Poultry and game-birds were often fattened in darkness and confinement, sometimes being blinded as well… Geese were thought to put on weight if the webs of their feet were nailed to the floor, and it was the custom of some seventeenth-century housewives to cut the legs off living fowl in the belief that it made their flesh more tender. In 1686 Sir Robert Southwell announced a new invention of "an oxhouse, where the cattle are to eat and drink in the same crib and not to stir until they be fitted for the slaughter." Dorset lambs were specially reared for the Christmas tables of the gentry by being imprisoned in little dark cabins.

Factory farming is also not a phenomenon of the 20th century:

During this long history of exploitation and cruelty, there had always been forces that pushed for restraint in the treatment of animals. But the driving motive was rarely an empathic concern for their inner lives. Vegetarianism, antivivisectionism, and other pro-animal movements have always had a wide range of rationales. Let's consider a few of them.

Many other millennia-old practices are thoroughly indifferent to animal suffering. Fishhooks and harpoons go back to the stone age, and even fishnets kill by slow suffocation. Bits, whips, spurs, yokes, and heavy loads made life miserable for beasts of burden, especially those who spent their days pushing drive shafts in dark mills and pumping stations. Any reader of Moby-Dick knows about the age-old cruelties of whaling. And then there were the blood sports that we saw in chapters 3 and 4, such as head-butting a cat nailed to a post, clubbing a pig, baiting a bear, and watching a cat burn to death.

I have mentioned in a number of places the mind's tendency to moralize the disgust-purity continuum. The equation holds at both ends of the scale: at one pole, we equate immorality with filth, carnality, hedonism, and dissoluteness; at the other, we equate virtue with purity, chastity, asceticism, and temperance. This cross talk affects our emotions about food. Meat-eating is messy and pleasurable, therefore bad; vegetarianism is clean and abstemious, therefore good.

People can be turned against meat by romantic ideologies as well. Prelapsarian, pagan, and blood-and-soil creeds can depict the elaborate process of procuring and preparing animals as a decadent artifice, and vegetarianism as a wholesome living off the land. For similar reasons, a concern over the use of animals in research can feed off an antipathy toward science and intellect in general, as when Wordsworth wrote in "The Tables Turned":

Also, since the human mind is prone to essentialism, we are apt to take the cliché "you are what you eat" a bit too literally. Incorporating dead flesh into one's body can feel like a kind of contamination, and ingesting a concentrate of animality can threaten to imbue the eater with beastly traits. Even Ivy League university students are vulnerable to the illusion. The psychologist Paul Rozin has shown that students are apt to believe that a tribe that hunts turtles for their meat and wild boar for their bristles are probably good swimmers, whereas a tribe that hunts wild boar for their meat and turtles for their shells are probably tough fighters.

Finally, since different subcultures treat animals in different ways, a moralistic concern with how the other guy treats his animals (while ignoring the way we do) can be a form of social one-upmanship. Blood sports in particular offer satisfying opportunities for class warfare, as when the middle class lobbies to outlaw the cockfighting enjoyed by the lower classes and the foxhunts enjoyed by the upper ones. Thomas Macaulay's remark that "the Puritan hated bearbaiting, not because it gave pain to the bear, but because it gave pleasure to the spectators' can mean that campaigns against violence tend to target the mindset of cruelty rather than just the harm to victims. But it also captures the insight that zoophily can shade into misanthropy.

Our meddling intellect

Mis-shapes the beauteous forms of things:--

We murder to dissect.

Sweet is the lore which Nature brings;

The Jewish dietary laws are an ancient example of the confused motives behind taboos on meat. Leviticus and Deuteronomy present the laws as unadorned diktats, since God is under no obligation to justify his commandments to mere mortals. But according to later rabbinical interpretations, the laws foster a concern with animal welfare, if only by forcing Jews to stop and think about the fact that the source of their meat is a living thing, ultimately belonging to God. Animals must be dispatched by a professional slaughterer who severs the animal's carotid artery, trachea, and esophagus with a clean swipe of a nick-free knife. This indeed may have been the most humane technology of the time, and was certainly better than cutting parts off a living animal or roasting it alive. But it is far from a painless death, and some humane societies today have sought to ban the practice. The commandment not to "seethe a kid in its mother's milk," the basis for the prohibition of mixing meat with dairy products, has also been interpreted as an expression of compassion for animals. But when you think about it, it's really an expression of the sensibilities of the observer. To a kid that is about to be turned into stewing meat, the ingredients of the sauce are the least of its concerns.

Cultures that have gone all the way to vegetarianism are also driven by a mixture of motives. In the 6th century BCE Pythagoras started a cult that did more than measure the sides of triangles: he and his followers avoided meat, largely because they believed in the transmigration of souls from body to body, including those of animals. Before the word vegetarian was coined in the 1840s, an abstention from meat and fish was called "the Pythagorean diet." The Hindus too based their vegetarianism on the doctrine of reincarnation, though cynical anthropologists like Marvin Harris have offered a more prosaic explanation: cattle in India were more precious as plow animals and dispensers of milk and dung (used as fuel and fertilizer) than they would have been as the main ingredient in beef curry. The spiritual rationale of Hindu vegetarianism was carried over into Buddhism and Jainism, though with a more explicit concern for animals rooted in a philosophy of nonviolence. Jain monks sweep the ground in front of them so as not to tread on insects, and some wear masks to avoid killing microbes by inhaling them.

But any intuition that vegetarianism and humanitarianism go together was shattered in the 20th-century by the treatment of animals under Nazism. Hitler and many of his henchmen were vegetarians, not so much out of compassion for animals as from an obsession with purity, a pagan desire to reconnect to the soil, and a reaction to the anthropocentrism and meat rituals of Judaism. In an unsurpassed display of the human capacity for moral compartmentalization, the Nazis, despite their unspeakable experiments on living humans, instituted the strongest laws for the protection of animals in research that Europe had ever seen. Their laws also mandated humane treatment of animals in farms, movie sets, and restaurants, where fish had to be anesthetized and lobsters killed swiftly before they were cooked. Ever since that bizarre chapter in the history of animal rights, advocates of vegetarianism have had to retire one of their oldest arguments: that eating meat makes people aggressive, and abstaining from it makes them peaceful.

Some of the early expressions of a genuinely ethical concern for animals took place in the Renaissance. Europeans had become curious about vegetarianism when reports came back from India of entire nations that lived without meat. Several writers, including Erasmus and Montaigne, condemned the mistreatment of animals in hunting and butchery, and one of them, Leonardo da Vinci, became a vegetarian himself.

There are barbarians who seize this dog, who so prodigiously surpasses man in friendship, and nail him down to a table, and dissect him alive to show you the mezaraic veins. You discover in him all the same organs of feeling as in yourself. Answer me, Machinist, has Nature really arranged all the springs of feeling in this animal to the end that he might not feel? Has he nerves that he may be incapable of suffering?

But it was in the 18th and 19th centuries that arguments for animal rights began to catch on. Part of the impetus was scientific. Descartes' substance dualism, which considered consciousness a free-floating entity that works separately from the brain, gave way to theories of monism and property dualism that equated, or at least intimately connected, consciousness with brain activity. This early neurobiological thinking had implications for animal welfare. As Voltaire wrote:

And as we saw in chapter 4, Jeremy Bentham's laser-beam analysis of morality led him to pinpoint the issue that should govern our treatment of animals: not whether they can reason or talk, but whether they can suffer. By the early 19th century, the Humanitarian Revolution had been extended from humans to other sentient beings, first targeting the most conspicuous form of sadism toward animals, blood sports, followed by the abuse of beasts of burden, livestock on farms, and laboratory animals. When the first of these measures, a ban on the abuse of horses, was introduced into the British Parliament in 1821, it elicited howls of laughter from MPs who said that it would lead to the protection of dogs and even cats. Within two decades that is exactly what happened. Throughout 19th-century Britain, a blend of humanitarianism and romanticism led to antivivisection leagues, vegetarian movements, and societies for the prevention of cruelty to animals. Biologists' acceptance of the theory of evolution following the publication of The Origin of Species in 1859 made it impossible for them to maintain that consciousness was unique to humans, and by the end of the century in Britain, they had acceded to laws banning vivisection.

One sometimes gets the impression that the mere words "Socialism" and "Communism" draw towards them with magnetic force every fruit-juice drinker, nudist, sandal-wearer, sex-maniac, Quaker, "Nature Cure" quack, pacifist, and feminist in England… The food-crank is by definition a person willing to cut himself off from human society in hopes of adding five years on to the life of his carcase; that is, a person out of touch with common humanity.

The campaign to protect animals lost momentum during the middle decades of the 20th century. The austerity from the two world wars had created a meat hunger, and the populace was so grateful for the flood of cheap meat from factory farming that it gave little thought to where the meat came from. Also, beginning in the nineteen-teens, behaviorism took over psychology and philosophy and decreed that the very idea of animal experience was a form of unscientific naïveté: the cardinal sin of anthropomorphism. Around the same time the animal welfare movement, like the pacifist movements of the 19th century, developed an image problem and became associated with do-gooders and health food nuts. Even one of the greatest moral voices of the 20th century, George Orwell, was contemptuous of vegetarians:

All this changed in the 1970s. The plight of livestock in factory farms was brought to light in Britain in a 1964 book by Ruth Harrison called Animal Machines. Other public figures soon took up the cause. Brigid Brophy has been credited with the term animal rights, which she deliberately coined by analogy: she wanted to associate "the case for non-human animals with that clutch of egalitarian or libertarian ideas which have sporadically, though quite often with impressively actual political results, come to the rescue of other oppressed classes, such as slaves or homosexuals or women."

The real turning point was the philosopher Peter Singer's 1975 book Animal Liberation, the so-called bible of the animal rights movement. The sobriquet is doubly ironic because Singer is a secularist and a utilitarian, and utilitarians have been skeptical of natural rights ever since Bentham called the idea "nonsense on stilts." But following Bentham, Singer laid out a razor-sharp argument for a full consideration of the interests of animals, while not necessarily granting them "rights." The argument begins with the realization that it is consciousness rather than intelligence or species membership that makes a being worthy of moral consideration. It follows that we should not inflict avoidable pain on animals any more than we should inflict it on young children or the mentally handicapped. And a corollary is that we should all be vegetarians. Humans can thrive on a modern vegetarian diet, and animals' interests in a life free of pain and premature death surely outweigh the marginal increase in pleasure we get from eating their flesh. The fact that humans "naturally" eat meat, whether by cultural tradition, biological evolution, or both, is morally irrelevant.

Like Brophy, Singer made every effort to analogize the animal welfare movement to the other Rights Revolutions of the 1960s and 1970s. The analogy began with his title, an allusion to colonial liberation, women's liberation, and gay liberation, and it continued with his popularization of the term speciesism, a sibling of racism and sexism. Singer quoted an 18th-century critic of the feminist writer Mary Wollstonecraft who argued that if she was right about women, we would also have to grant rights to "brutes." The critic had intended it as a reductio ad absurdum, but Singer argued that it was a sound deduction. For Singer, these analogies are far more than rhetorical techniques. In another book, The Expanding Circle, he advanced a theory of moral progress in which human beings were endowed by natural selection with a kernel of empathy toward kin and allies, and have gradually extended it to wider and wider circles of living things, from family and village to clan, tribe, nation, species, and all of sentient life. The book you are reading owes much to this insight.

Singer's moral arguments were not the only forces that made people sympathetic to animals. In the 1970s it was a good thing to be a socialist, fruit-juice drinker, nudist, sandal-wearer, sex-maniac, Quaker, Nature Cure quack, pacifist, and feminist, sometimes all at the same time. The compassion-based argument for vegetarianism was soon fortified with other arguments: that meat was fattening, toxic, and artery-hardening; that growing crops to feed animals rather than people was a waste of land and food; and that the effluvia of farm animals was a major pollutant, particularly methane, the greenhouse gas that comes out of both ends of a cow.

Whether you call it animal liberation, animal rights, animal welfare, or the animal movement, the decades since 1975 in Western culture have seen a growing intolerance of violence toward animals. Changes are visible in at least half a dozen ways.

I've already mentioned the first: the protection of animals in laboratories. Not only are live animals now protected from being hurt, stressed, or killed in the conduct of science, but in high school biology labs the venerable custom of dissecting pickled frogs has gone the way of inkwells and slide rules. (In some schools it has been replaced by V-Frog, a virtual reality dissection program.) And in commercial laboratories the routine use of animals to test cosmetics and household products has come under fire. Since the 1940s, following reports of women being blinded by mascara containing coal tar, many household products have been tested for safety with the infamous Draize procedure, which applies a compound to the eyes of rabbits and looks for signs of damage. Until the 1980s few people had heard of the Draize test, and until the 1990s few would have recognized the term cruelty-free, the designation for products that avoid it. Today the term is emblazoned on thousands of consumer goods and has become familiar enough that the label "cruelty-free condoms' does not raise an eyebrow. Animal testing in consumer product labs continues, but has been increasingly regulated and reduced.

Even the proud bullfight has been threatened. In 2004 the city of Barcelona outlawed the deadly contests between matador and beast, and in 2010 the ban was extended to the entire region of Catalonia. The state-run Spanish television network had already ended live coverage of bullfights because they were deemed too violent for children. The European Parliament has considered a continent-wide ban as well. Like formal dueling and other violent customs sanctified by pomp and ceremony, bullfighting may eventually bite the dust, not because compassion condemns it or governments outlaw it, but because detraction will not suffer it. In his 1932 book Death in the Afternoon, Ernest Hemingway explained the primal appeal of the bullfight:

Another conspicuous change is the outlawing of blood sports. I have already mentioned that since 2005 the British aristocracy has had to retire its bugles and bloodhounds, and in 2008 Louisiana became the last American state to ban cockfights, a sport that had been popular throughout the world for centuries. Like many prohibited vices, the practice continues, particularly among immigrants from Latin America and Southeast Asia, but it has long been in decline in the United States and has been outlawed in many other countries as well.

[The matador] must have a spiritual enjoyment of the moment of killing. Killing cleanly and in a way which gives you esthetic pleasure and pride has always been one of the greatest enjoyments of a part of the human race. Once you accept the rule of death, "Thou shalt not kill" is an easily and naturally obeyed commandment. But when a man is still in rebellion against death he has pleasure in taking to himself one of the godlike attributes, that of giving it. This is one of the most profound feelings in those men who enjoy killing. These things are done in pride and pride, of course, is a Christian sin and a pagan virtue. But it is pride which makes the bull-fight and true enjoyment of killing which makes the great matador.

Thirty years later, Tom Lehrer described his experience of a bullfight a bit differently. "There is surely nothing more beautiful in this world," he exclaimed, "than the sight of a lone man facing singlehandedly a half a ton of angry pot roast." In the climactic verse of his ballad, he sang:

Got run over.

As they stuck the bull in their own clever way,

For I hadn't had so much fun since the day

I cheered at the bandilleros' display,

My brother's dog Rover

"Rover was killed by a Pontiac," Lehrer added, "and it was done with such grace and artistry that the witnesses awarded the driver both ears and the tail." The reaction of young Spaniards today is closer to Lehrer's than to Hemingway's. Their heroes are not matadors but singers and football players who become famous without the spiritual and aesthetic pride of killing anything. While bullfighting retains a loyal following in Spain, the crowds are middle-aged and older.

Hunting is another pastime that has been in decline. Whether it is from compassion for Bambi or an association with Elmer Fudd, fewer Americans shoot animals for fun. Figure 7-26 shows the declining proportion of Americans in the past three decades who have told the General Social Survey that either they or their spouse hunts. Other statistics show that the average age of hunters is steadily creeping upward.

It's not just that Americans are spending more time behind video screens and less in the great outdoors. According to the U. S. Fish and Wildlife Service, in the decade between 1996 and 2006, while the number of hunters, days of hunting, and dollars spent on hunting declined by about 10 to 15 percent, the number of wildlife watchers, days of wildlife watching, and dollars spent on wildlife watching increased by 10 to 20 percent. People still like to commune with animals; they would just rather look at them than shoot them. It remains to be seen whether the decline will be reversed by the locavore craze, in which young urban professionals have taken up hunting to reduce their food miles and harvest their ownfree-range, grass-fed, sustainable, humanely slaughtered meat.

It's hard to imagine that fishing could ever be considered a humane sport, but anglers are doing their best. Some of them take catch-and-release a step further and release the catch before it even breaks the surface, because expofurther and release the catch before it even breaks the surface, because exposure to the air is stressful to a fish. Better still is hookless fly-fishing: the angler watches the trout take the fly, feels a little tug on the line, and that's it. One of them describes the experience: "I entered the trout's world and got among them in a much more natural way than ever before. I didn't interrupt their feeding rhythms. They took the fly continually, and I still got that little jolt of pleasure you feel when a fish takes your fly. I don't want to harass or harm trout anymore, so now there's a way for me to do that and still keep fishing."

No Tea Partiers Were Harmed in the Protesting of This Health Care Bill.

No Polar Bears Were Harmed in the Making of This Commercial.

And do you recognize this trope?

It comes from the trademarked certification of the American Humane Association that no animals were harmed in the making of a motion picture, displayed in the rolling credits after the names of the gaffer and key grip. In response to movies that depicted horses plunging over cliffs by actually filming horses plunging over cliffs, the AHA created its film and television unit to develop guidelines for the treatment of animals in films. As the association explains, "Today's consumers, increasingly savvy about animal welfare issues, have forged a partnership with American Humane to demand greater responsibility and accountability from entertainment entities that use animal actors'-- a term they insist on, because, they explain, "animals are not props." Their 131-page Guidelines for the Safe Use of Animals in Filmed Media, first compiled in 1988, begins with a definition of animal ("any sentient creature, including birds, fish, reptiles and insects') and leaves no species or contingency unregulated. Here is a page I turned to at random:

Source: General Social Survey, http://www. norc. org/GSS+Website/.

No Trees Were Harmed in the Making of This Blog Post.

FIGURE 7-26: Percentage of American households with hunters, 1977-2006

No Hamsters Were Harmed in the Making of This Book Trailer.

No Goats Were Harmed in the Writing of This Review.

No Cans of Diet Coke Were Harmed in the Production of This Product.

WATER EFFECTS (Also see Water Safety in Chapter 5.)

6-2. No animal shall be subjected to extreme, forceful rain simulation. Water pressure and the velocity of any fans used to create this effect must be monitored at all times.

6-3. Rubber mats or other non-slip material or surface shall be provided when simulating rain. If effects call for mud, the depth of the mud must be approved by American Humane prior to filming. When necessary, a non-slip surface shall be provided underneath the mud.

Source: American Humane Association, Film and Television Unit, 2010.

The AHA boasts that "since the introduction of the Guidelines, animal accidents, illnesses and deaths on the set have sharply declined." They back it up with numbers, and since I like to tell my story with graphs, figure7-27 is one that shows the number of films per year designated as "unacceptable" because of mistreatment of animal actors.

FIGURE 7-27: Number of motion pictures per year in which animals were harmed, 1972-2010

And finally we get to meat. If someone were to count up every animal that has lived on earth in the past fifty years and tally the harmful acts done to them, he or she might argue that no progress has been made in the treatment of animals. The reason is that the Animal Rights Revolution has been partly canceled out by another development, the Broiler Chicken Revolution. The 1928 campaign slogan "A chicken in every pot" reminds us that chicken was once thought of as a luxury. The market responded by breeding meatier chickens and raising them more efficiently, if less humanely: factory-farmed chickens have spindly legs, live in cramped cages, breathe fetid air, and are handled roughly when transported and slaughtered. In the 1970s consumers became convinced that white meat was healthier than red (a trend exploited by the National Pork Board when it came up with the slogan "The Other White Meat"). And since poultry are smallbrained creatures from a different biological class, many people have a vague sense that they are less fully conscious than mammals. The result was a massive increase in the demand for chicken, surpassing, by the early 1990s, the demand for beef. The unintended consequence was that billions more unhappy lives had to be brought into being and snuffed out to meet the demand, because it takes two hundred chickens to provide the same amount of meat as a single cow. Now, factory farming and cruel treatment of poultry and livestock go back centuries, so the baleful trend was not a backsliding of moral sensibilities or an increase in callousness. It was a stealthy creeping up of the numbers, driven by changes in economics and taste, which had gone undetected because a majority of people had always been incurious about the lives of chickens. The same is true, to a lesser extent, of the animals that provide us with the other white meat.

And if that is not enough to convince you that animal rights have been taken to a new level, consider the events of June 16, 2009, as recounted in a New York Times article entitled "What's White, Has 132 Rooms, and Flies?" The answer to the riddle is the White House, which had recently become infested with the bugs. During a televised interview a large fly orbited President Obama's head. When the Secret Service did not wrestle it to the ground, the president took matters into his own hands, using one of them to smack the fly on the back of the other. "I got the sucker," boasted the exterminator in chief. The footage became a YouTube sensation but drew a complaint from People for the Ethical Treatment of Animals. They noted on their blog, "It can't be said that President Obama wouldn't hurt a fly," and sent over one of their Katcha Bug Humane Bug Catchers "in the event of future insect incidents."

But the tide has begun to turn. One sign is the increase in vegetarianism. I'm sure I was not the only dinner host in the 1990s to have had one of my guests announce as he sat down at the table, "Oh, I forgot to tell you. I don't eat dead animals." Since that era the question "Do you have any food restrictions?" has become a part of the etiquette of a dinner invitation, and participants at conference dinners can now tick a box that will replace a plate of rubber chicken with a plate of sodden eggplant. The trend was noted in 2002, when Time magazine ran a cover story entitled: "Should You Be a Vegetarian? Millions of Americans Are Going Meatless."

The food industry has responded with a cornucopia of vegetarian and vegan products. The faux-meat section of my local supermarket offers Soyburgers, Gardenburgers, Seitanburgers, Veggie Burger Meatless Patties, Tofu Pups, Not Dogs, Smart Dogs, Fakin Bacon, Jerquee, Tofurky, Soy Sausage, Soyrizo, Chik Patties, Meatless Buffalo Wings, Celebration Roast, Tempeh Strips, Terkettes, Veggie Protein Slices, Vege-Scallops, and Tuno. The technological and verbal ingenuity is testimony both to the popularity of the new vegetarianism and to the persistence of ancient meat hunger. Those who enjoy a hearty breakfast can serve their Veggie Breakfast Strips with Tofu Scramblers, perhaps in an omelet with Soya Kaas, Soymage, or Veganrella. And for dessert there's Ice Bean, Rice Dream, and Tofutti, perhaps garnished with Hip Whip and a cherry on top. The ultimate replacement for meat would be animal tissue grown in culture, sometimes called meat without feet. The everoptimistic People for the Ethical Treatment of Animals has offered a milliondollar prize to the first scientist who brings cultured chicken meat to market.

But is vegetarianism at least trending upward? As best we can tell, it is. In the U. K. the Vegetarian Society gathers up the results of every opinion poll it can find and presents the data on its information sheets. In figure 7-28 I've plotted the results of all the questions that ask a national sample of respondents whether they are vegetarians. The best-fitting straight line suggests that over the past two decades, vegetarianism has more than tripled, from about 2 percent of the population to about 7 percent. In the United States, the Vegetarian Resource Group has commissioned polling agencies to ask Americans the more stringent question of whether they eat meat, fish, or fowl, excluding the flexitarians and those with creative Linnaean taxonomies. The numbers are smaller, but the trend is similar, more than tripling in about fifteen years.

For all the visibility of vegetarianism, pure vegetarians still make up just a few percentage points of the population. It's not easy being green. Vegetarians are surrounded by dead animals and the carnivores who love them, and meat hunger has not been bred out of them. It's not surprising that many fall off the wagon: at any moment there are three times as many lapsed vegetarians as observant ones. Many of those who continue to call themselves vegetarians have convinced themselves that a fish is a vegetable, because they partake of fish and seafood and sometimes even chicken. Others parse their dietary restrictions like Conservadox Jews in a Chinese restaurant, allowing themselves exemptions for narrowly defined categories or for food eaten outside the home. The demographic sector with the largest proportion of vegetarians is teenage girls, and their principal motive may not be compassion for animals. Vegetarianism among teenage girls is highly correlated with eating disorders.

FIGURE 7-28: Vegetarianism in the United States and United Kingdom, 1984-2009

With all the signs of increasing concern with animal welfare, it may be surprising that the percentage of vegetarians, though rising, is still so low. But it really shouldn't be. Being a vegetarian and being concerned with animal welfare are not the same thing. Not only do vegetarians have motives other than animal welfare -- health, taste, ecology, religion, driving their mothers crazy -- but people who are concerned with animal welfare may wonder whether the symbolic statement of vegetarianism is the best way to reduce animal suffering. They may feel that the hamburgers they altruistically forgo are unlikely to register amid the noise in the vast national demand for meat or to lead to the sparing of the lives of any cows. And even if they did, the lives of the remaining cows would be no more pleasant. Changing the practices of the food industry is a collective action dilemma, in which individuals are tempted to shirk from private sacrifices that have marginal effects on aggregate welfare.

Sources: U. K.: Vegetarian Society, http://www. vegsoc. org/info/. Excluded are polls that ask about households, ask students, or ask about "strict" vegetarians. United States: Vegetarian Resource Group, Vegetarian Journal. 2009: http://www. vrg. org/press/2009poll. htm. 2005 and 2003: http://www. vrg. org/journal/vj2006issue4/vj2006issue4poll. htm. 2000: http://www. vrg. org/nutshell/poll2000. htm. 1997: http://www. vrg. org/journal/vj97sep/979poll. htm. 1994: http: www. vrg. org/nutshell/poll. htm.

The increase in vegetarianism, though, is a symbolic indicator of a broader concern for animals that can be seen in other forms. People who don't abstain from meat as a matter of principle may still eat less of it. (American consumption of meat from mammals has declined since 1980.) Restaurants and supermarkets increasingly inform their patrons about what their main course fed on and how freely it ranged while it was still on the hoof or claw. Two of the major poultry processors in the United States announced in 2010 that they were switching to a more humane method of slaughtering, in which the birds are knocked out by carbon dioxide before being hung by their feet to have their throats slit. The marketers have to walk a fine line. Diners are happy to learn that their entrée was humanely treated until its last breath, but they would rather not know the details of exactly how it met its end. And even the most humane technique has an image problem. As one executive said, "I don't want the public to say we gas our chickens."

More significantly, a majority of people support legal measures that would solve the collective action problem by approving laws that force farmers and meatpackers to treat animals more humanely. In a 2000 poll 80 percent of Britons said "they would like to see better welfare conditions for Britain's farm animals." Even Americans, with their more libertarian temperament, are willing to empower the government to enforce such conditions. In a 2003 Gallup poll, a remarkable 96 percent of Americans said that animals deserve at least some protection from harm and exploitation, and only 3 percent said that they need no protection "since they are just animals." Though Americans oppose bans on hunting or on the use of animals in medical research and product testing, 62 percent support "strict laws concerning the treatment of farm animals." And when given the opportunity, they translate their opinions into votes. Livestock rights have been written into the laws of Arizona, Colorado, Florida, Maine, Michigan, Ohio, and Oregon, and in 2008, 63 percent of California voters approved the Prevention of Farm Animal Cruelty Act, which bans veal crates, poultry cages, and sow gestation crates that prevent the animal from moving around. There is a cliché in American politics: as California goes, so goes the country.

And perhaps as Europe goes, so goes California. The European Union has elaborate regulations on animal care "that start with the recognition that animals are sentient beings. The general aim is to ensure that animals need not endure avoidable pain or suffering and obliges the owner/keeper of animals to respect minimum welfare requirements." Not every country has gone so far as Switzerland, which enacted 150 pages of regulations that force dog owners to attend a four-hour "theory" course and legislate how pet owners may house, feed, walk, play with, and dispose of their pets. (No more flushing live goldfish down the toilet.) But even the Swiss balked at a 2010 referendum that would have nationalized a Zurich policy that pays an "animal advocate" to haul offenders into criminal court, including an angler who boasted to a local newspaper that he took ten minutes to land a large pike. (The angler was acquitted; the pike was eaten.) All this may sound like American conservatives' worst nightmare, but they too are willing to allow the government to regulate animal welfare. In the 2003 poll, a majority of Republicans favored passing "strict laws" on the treatment of farm animals.

Maybe, but maybe not. The analogy between oppressed people and oppressed animals has been rhetorically powerful, and insofar as we are all sentient beings, it has a great deal of intellectual warrant. But the analogy is not exact -- African Americans, women, children, and gay people are not broiler chickens -- and I doubt that the trajectory of animal rights will be a time-lagged copy of the one for human rights. In his book Some We Love, Some We Hate, Some We Eat, the psychologist Hal Herzog lays out the many reasons why it's so hard for us to converge on a coherent moral philosophy to govern our dealings with animals. I'll mention a few that have struck me.

How far will it go? People often ask me whether I think the moral momentum that carried us from the abolition of slavery and torture to civil rights, women's rights, and gay rights will culminate in the abolition of meat-eating, hunting, and animal experimentation. Will our 22nd-century descendants be as horrified that we ate meat as we are that our ancestors kept slaves?

One impediment is meat hunger and the social pleasures that go with the consumption of meat. Though traditional Hindus, Buddhists, and Jains prove that a meatless society is possible, the 3 percent market share of vegetarian diets in the United States shows that we are very far from a tipping point. While gathering the data for this chapter, I was excited to stumble upon a 2004 Pew Research poll in which 13 percent of the respondents were vegetarians. Upon reading the fine print, I discovered that it was a poll of supporters of the presidential candidacy of Howard Dean, the left-wing governor of Vermont. That means that even among the crunchiest granolas in Ben-and-Jerry land, 87 percent still eat meat. 300

But the impediments run deeper than meat hunger. Many interactions between humans and animals will always be zero-sum. Animals eat our houses, our crops, and occasionally our children. They make us itch and bleed. They are vectors for diseases that torment and kill us. They kill each other, including endangered species that we would like to keep around. Without their participation in experiments, medicine would be frozen at its current state, and billions of living and unborn people would suffer and die for the sake of mice. An ethical calculus that gave equal weight to any harm suffered by any sentient being, allowing no chauvinism toward our own species, would prevent us from trading off the well-being of animals for an equivalent well-being of humans -- for example, shooting a wild dog to save a little girl. To be sure, the interests of humans could be given some extra points by virtue of our zoological peculiarities, such as that our big brains allow us to savor our lives, reflect on our past and future, dread death, and enmesh our well-being with those of others in dense social networks. But the human life taboo, which among other things protects the lives of mentally incompetent people just because they are people, would have to go. Singer himself unflinchingly accepts this implication of a species-blind morality. But it will not take over Western morality anytime soon.

Ultimately the move toward animal rights will bump against some of the most perplexing enigmas in the space of human thoughts, a place where moral intuitions start to break down. One is the hard problem of consciousness, namely how sentience arises from neural information processing. Descartes was certainly wrong about mammals, and I am pretty sure he was wrong about fish. But was he wrong about oysters? Slugs? Termites? Earthworms? If we wanted ethical certainty in our cooking, gardening, home repair, and recreation, we would need nothing less than a solution to this philosophical conundrum. Another paradox is that human beings are simultaneously rational, moral agents and organisms that are part of nature red in tooth and claw. Something in me objects to the image of a hunter shooting a moose. But why am I not upset by the image of a grizzly bear that renders it just as dead? Why don't I think it's a moral imperative to tempt the bear away with all-soy meatless moose patties? Should we arrange for the gradual extinction of carnivorous species, or even genetically engineer them into herbivores? We recoil from these thought experiments because, rightly or wrongly, we assign some degree of ethical weight to what we feel is "natural." But if the natural carnivory of other species counts for something, why not the natural carnivory of Homo sapiens -- particularly if we deploy our cognitive and moral faculties to minimize the animals' suffering?

These imponderables, I suspect, prevent the animal rights movement from duplicating the trajectory of the other Rights Revolutions exactly. But for now the location of the finish line is beside the point. There are many opportunities in which enormous suffering by animals can be reduced at a small cost to humans. Given the recent changes in sensibilities, it is certain that the lives of animals will continue to improve.