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.
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.301 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.302 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?303 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.
WHENCE THE RIGHTS REVOLUTIONS?
When I began my research for this