The Yale Law Journal

December 2000

Animal Rights

Richard A. Posner
110 Yale L.J. 527 (2000)

The "animal rights" movement is gathering steam, and Steven Wise is one of the pistons. A lawyer whose practice is the protection of animals, he has now written a book in which he urges courts in the exercise of their common-law powers of legal rulemaking to confer legally enforceable rights on animals, beginning with chimpanzees and bonobos (the two most intelligent primate species). Although Wise is well-informed about his subject--the biological as well as legal aspects--this is not an intellectually exciting book. I do not say this in criticism. Remember who Wise is: a practicing lawyer who wants to persuade the legal profession that courts should do much more to protect animals. Judicial innovation proceeds incrementally; as Holmes put it, the courts, in their legislative capacity, "are confined from molar to molecular motions." Wise's practitioner's perspective is, as we shall see, both the strength and the weakness of the book.

If Wise is to persuade his chosen audience, he must show how courts can proceed incrementally, building on existing cases and legal concepts, toward his goal of radically enhanced legal protection for animals. Recall the process by which, starting from the unpromising principle that "separate but equal" was constitutional, the Supreme Court outlawed official segregation. First, certain public facilities were held not to be equal; then segregation of law schools was invalidated as inherently unequal because of the importance of the contacts made in law school to a successful legal practice; then segregation of elementary schools was outlawed on the basis of social scientific evidence that this segregation, too, was inherently unequal; then the "separate but equal" principle itself, having been reduced to a husk, was quietly buried and the no-segregation principle of the education cases extended to all public facilities, including rest rooms and drinking fountains.

That is the process that Wise envisages for the animal-rights movement, although the end point is less clear. We have, Wise points out, a robust conception of human rights, and we apply it even to people who by reason of retardation or other mental disability cannot enforce their own rights but need a guardian to do it for them. The evolution of human-rights law has involved not only expanding the number of rights but also expanding the number of rights-holders, notably by adding women and blacks. (Much of Wise's book is about human rights, and about the methodology by which judges enlarge human rights in response to changed understandings.) We also have a long history of providing legal protections for animals that recognize their sentience, their emotional capacity, and their capacity to suffer pain; these protections have been growing too.

Wise wants to merge these legal streams by showing that the apes that are most like us genetically, namely the chimpanzees and the bonobos, are also very much like us in their mentation, which exceeds that of human infants and profoundly retarded people. He believes that they are enough like us to be in the direct path of rights expansion. So far as deserving to have rights is concerned, he finds no principled difference between the least mentally able people and the most mentally able animals, as the two groups overlap--or at least too little difference to justify interrupting, at the gateway to the animal kingdom, the expansive rights trend that he has discerned. The law's traditional dichotomy between humans and animals is a vestige of bad science and of a hierarchizing tendency that put men over animals just as it put free men over slaves. Wise does not say how many other animal species besides chimpanzees and bonobos he would like to see entitled, but he makes clear that he regards entitling those two species as a milestone, not as the end of the road.