1.

The phrase “Animal Liberation” appeared in the press for the first time on the April 5, 1973, cover of The New York Review of Books. Under that heading, I discussed Animals, Men and Morals, a collection of essays on our treatment of animals, which was edited by Stanley and Roslind Godlovitch and John Harris.1 The article began with these words:

We are familiar with Black Liberation, Gay Liberation, and a variety of other movements. With Women’s Liberation some thought we had come to the end of the road. Discrimination on the basis of sex, it has been said, is the last form of discrimination that is universally accepted and practiced without pretense, even in those liberal circles which have long prided themselves on their freedom from racial discrimination. But one should always be wary of talking of “the last remaining form of discrimination.”

In the text that followed, I urged that despite obvious differences between humans and nonhuman animals, we share with them a capacity to suffer, and this means that they, like us, have interests. If we ignore or discount their interests, simply on the grounds that they are not members of our species, the logic of our position is similar to that of the most blatant racists or sexists who think that those who belong to their race or sex have superior moral status, simply in virtue of their race or sex, and irrespective of other characteristics or qualities. Although most humans may be superior in reasoning or in other intellectual capacities to nonhuman animals, that is not enough to justify the line we draw between humans and animals. Some humans—infants and those with severe intellectual disabilities—have intellectual capacities inferior to some animals, but we would, rightly, be shocked by anyone who proposed that we inflict slow, painful deaths on these intellectually inferior humans in order to test the safety of household products. Nor, of course, would we tolerate confining them in small cages and then slaughtering them in order to eat them. The fact that we are prepared to do these things to nonhuman animals is therefore a sign of “speciesism”—a prejudice that survives because it is convenient for the dominant group—in this case not whites or males, but all humans.

That essay and the book that grew out of it, also published by The New York Review,2 are often credited with starting off what has become known as the “animal rights movement”—although the ethical position on which the movement rests needs no reference to rights. Hence the essay’s thirti-eth anniversary provides a convenient opportunity to take stock both of the current state of the debate over the moral status of animals and of how effective the movement has been in bringing about the practical changes it seeks in the way we treat animals.

2.

The most obvious difference between the current debate over the moral status of animals and that of thirty years ago is that in the early 1970s, to…