Who is a person?

 The question of who is a person (in law, and in welfare economics) is sometimes vexing. Arguments about abortion focus on the personhood of a fetus. The growing possibility of successful transplants of pig organs into humans might be viewed with less optimism if we thought of pigs as people (and transplants from great apes would probably be repugnant because apes are uncomfortably close to being human).  In economic theory we often speak of Pareto improvements as those that raise the welfare of "everyone," with the assumption that the model takes care of specifying the full set of people we are concerned with.  As we make progress in artificial intelligence, we may find ourselves asking about the personhood of machines.

In the meantime, here's a New Yorker story about a lawsuit brought on behalf of an elephant in the Bronx zoo:

The Elephant in the Courtroom. A curious legal crusade to redefine personhood is raising profound questions about the interdependence of the animal and human kingdoms.   By Lawrence Wright

"The subject of the petition was Happy, an Asian elephant in the Bronx Zoo. American law treats all animals as “things”—the same category as rocks or roller skates. However, if the Justice granted the habeas petition to move Happy from the zoo to a sanctuary, in the eyes of the law she would be a person. She would have rights.

"Humanity seems to be edging toward a radical new accommodation with the animal kingdom. In 2013, the government of India banned the capture and confinement of dolphins and orcas, because cetaceans have been proved to be sensitive and highly intelligent, and “should be seen as ‘non-human persons’ ” with “their own specific rights.” The governments of Hungary, Costa Rica, and Chile, among others, have issued similar restrictions, and Finland went so far as to draft a Declaration of Rights for cetaceans. In Argentina, a judge ruled that an orangutan at the Buenos Aires Eco-Park, named Sandra, was a “nonhuman person” and entitled to freedom—which, in practical terms, meant being sent to a sanctuary in Florida. The chief justice of the Islamabad High Court, in Pakistan, asserted that nonhuman animals have rights when he ordered the release of an elephant named Kaavan, along with other zoo animals, to sanctuaries; he even recommended the teaching of animal welfare in schools, as part of Islamic studies. In October, a U.S. court recognized a herd of hippopotamuses originally brought to Colombia by the drug lord Pablo Escobar as “interested persons” in a lawsuit that would prevent their extermination. The Parliament of the United Kingdom is currently weighing a bill, backed by Prime Minister Boris Johnson, that would consider the effect of government action on any sentient animal.

"Although the immediate question before Justice Tuitt was the future of a solitary elephant, the case raised the broader question of whether animals represent the latest frontier in the expansion of rights in America—a progression marked by the end of slavery and by the adoption of women’s suffrage and gay marriage. 

...

"Having lost the chimpanzee cases in New York, Wise and his team armed themselves with dozens of friend-of-the-court briefs in support of personhood for Happy. One of them came from Laurence Tribe, the Harvard legal scholar. “It cannot pass notice that African Americans who had been enslaved famously used the common law writ of habeas corpus in New York to challenge their bondage and to proclaim their humanity, even when the law otherwise treated them as mere things,” Tribe wrote. “Women in England were once considered the property of their husbands and had no legal recourse against abuse until the Court of King’s Bench began in the 17th century to permit women and their children to utilize habeas corpus to escape abusive men. Indeed, the overdue transition from thinghood to personhood through the legal vehicle of habeas corpus must be deemed among the proudest elements of the heritage of that great writ of liberation.”

"A precedent that Wise particularly favors is a 1772 case in England concerning James Somerset, a Black man enslaved to Charles Stewart, a customs officer in Boston. When Stewart brought him to England, Somerset briefly escaped, and upon his recapture Stewart had him imprisoned on a ship bound for Jamaica, where he was to be sold on the slave market. English supporters of Somerset filed for a writ of habeas corpus to gain his freedom. The case came before Lord Mansfield, a consequential figure in the British legal tradition. Although slavery had not been legally endorsed in Britain, an estimated fifteen thousand enslaved people lived there, and hundreds of thousands lived in British territories. Recognizing Somerset as a legal person would not just liberate a single individual but set a precedent that could be financially ruinous for slaveholders. Mansfield declared, “Let justice be done, though the heavens may fall.” He ruled that slavery was “so odious” that common law could not support it.

“That was the beginning of the end of slavery, first in England, then at least in the northern part of the U.S.,” Wise said in Tuitt’s court.

“Did they actually say the person who was enslaved was a person?” the Justice asked.

“No, they said he was free, he had rights,” Wise responded. “A person is an entity who has the capacity for rights, any entity who has a right was automatically a person.”