ALBANY, New York—Can an animal who possesses the essential qualities of personhood ever be considered, in the eyes of the law, a person?

As of now, the answer is no. But a panel of New York state judges yesterday considered that question, which was posed by a group called the Nonhuman Rights Project on behalf of a 26-year-old chimpanzee named Tommy.

Tommy presently is kept alone in a cage in a warehouse in Gloversville, New York. Eventually, hope his advocates, he will be moved to a sanctuary and into the history books as the first nonhuman animal person, possessing rights previously restricted to Homo sapiens.

"Chimpanzees are autonomous, self-determining beings. Why shouldn't they be legal persons?" attorney Steven Wise, founder of the Nonhuman Rights Project, said to WIRED last week. "How is it that we can ignore the autonomy of a nonhuman, while making [autonomy] to be a supreme value of a human being?"

In December, Wise and the Nonhuman Rights Project filed so-called writs of habeas corpus—requests that a judge consider whether a person is being wrongfully imprisoned—on behalf of Tommy and, in separate cases, three other chimpanzees. Their briefs referenced several centuries of judicial precedents attesting to the importance of autonomy to legal definitions of personhood.

Also accompanying the briefs were affidavits from nine leading primatologists. According to exhaustive scientific evidence, testified the primatologists, chimpanzees are deeply self-aware and self-determined, capable not only of pleasure and suffering, but of anticipating the future, remembering the past and making conscious choices about their lives.

Tommy can't speak our language, but it can be assumed he doesn't want to spend his life alone in a cage, Wise argued. "Both as a matter of liberty and a matter of equality, you can't say that an autonomous person doesn't have any rights simply because he is a chimpanzee," he said. "He is remarkably like us, and he suffers like us."

Wise is quick to emphasize that the Nonhuman Rights Project isn't seeking full human rights for Tommy and other chimpanzees. Rather, they're seeking recognition of just one right: to not be imprisoned against one's will. After that, says Wise, other rights can be negotiated as society considers appropriate.

Yet just that single recognition would be a history-making decision, and animal law experts say convincing even a sympathetic judge to take that first, enormous step will be tremendously difficult. "You make a very strong argument," concluded Joseph Sise, the judge who heard Tommy's case in December, in his rejection of the claim. "I'm sorry I can't sign your order, but I hope you continue."

Yesterday's hearing, held in a spectator-packed state appeals courtroom, represents that continuation. If their appeal is granted, Wise and the Nonhuman Rights Project will argue Tommy's case again in a lower court.

Tommy's owner, Patrick Lavery, did not appear in court or appoint counsel to defend himself, leaving the argument to be held between the judges and Wise. The judges did not challenge the facts of Tommy's captivity or the scientific claims of chimpanzee abilities, but rather Wise's legal argument.

"There are no writs of habeas corpus that in this state have involved nonhumans. Would you agree?" asked Justice Karen Peters, who presided over the case.

"I do agree. This is a novel case in that way," answered Wise, but he likened it to 19th century cases involving slave children who were placed in the custody of a guardian after entering northern states and winning habeas corpus requests filed on their behalf by abolitionists.

"Tommy is the equivalent of a human child," said Wise. "He is a cognitive and extraordinarily complex being." Asked whether Tommy's cognitive abilities had specifically been assessed, Wise said they had not, but "there is no reason to think that Tommy is not that way."

Tommy, the 26-year-old chimpanzee plaintiff of the Nonhuman Rights Project’s first lawsuit, in his cage in Gloversville, New York. Pennebaker Hegedus Films

Justice Elizabeth Garry asked whether the lawsuit was, at its heart, about promoting Tommy's well-being. That line of questioning, said animal law attorney Kevin Schneider in an interview after the hearing, was a sort of legal trap: It would have moved the lawsuit away from personhood and onto grounds of animal cruelty.

"This is not a welfare issue," argued Wise, who says existing animal welfare statutes permit Tommy to be kept alone in a cage. "The question is whether there is an unlawful detention here." To which Peters rejoined: What is unlawful about the detention?

If Tommy is a legal person, said Wise, then keeping a person in solitary confinement in a cage is unlawful detention. But Peters noted that if a writ of habeas corpus is indeed granted, Tommy will not actually go free. Rather, he'll be moved to a chimpanzee sanctuary: from one cage, then, to a larger one. "How do we define cage?" she asked.

Wise described conditions at Save the Chimps, a sanctuary in Florida that could house Tommy: artificial lakes containing islands where Tommy, who was born in captivity and can't be put into the wild, can "live in a condition that is as close to the wild as is possible in North America."

Peters asked whether the Nonhuman Rights Project might be better served by asking legislatures rather than judges to change the law. Wise replied that similar arguments were made regarding the personhood of slaves. "I keep having a difficult time with your using slavery as an analogy," said Peters.

"We are in no way comparing Tommy to any human slaves," said Wise, but "Tommy has the autonomy and self-determination sufficient for him to be a legal person."

Justice Michael Lynch then read the definition of person according to Black's Law Dictionary, the most widely-used legal dictionary in the United States. "A human being," begins the entry.

"This is a novel case," acknowledged Wise again, but "a legal person is a legal concept. It is not a biological concept."

Though spectators at the hearing were largely supportive of Wise, not everyone agreed with his arguments. "I don't think you should ever give human rights to animals," said Bob Kohn, a technology attorney and artificial intelligence theorist. "If you're going to give a nonhuman animal rights for being autonomous, then why don't you give a robot rights for being autonomous as well?"

The appeals court's decision is expected in the coming weeks. In the meantime, few legal scholars think much of Tommy's chances. "At bottom, it's about how wide or narrow the courthouse doors are going to be in New York," said Jonathan Lovvorn, senior litigator at the Humane Society of the United States.

Lovvorn referenced their own difficulties having existing laws respected for cases involving cats and dogs. "The odds of letting in a chimp in are low, at least in my opinion," he said.

David Cassuto, an animal law scholar at Pace University, struck a similar note. Though he supports the Nonhuman Rights Project's efforts, and thinks their arguments have "significant potential," he said that judges are simply reluctant to transform laws in such profound ways.

Cassuto's preferred strategy is to pressure lawmakers to improve animal cruelty statutes, which are largely toothless and poorly enforced. Many animal advocates, he said, are also not convinced that autonomy is the basis of our ethical obligations to animals. "Is autonomy the legal basis for humane treatment?" Cassuto asked. "I'd say no. I'd say it's sentience and the ability to suffer."

Wise, who in his decades-long career has argued cruelty cases on behalf of dogs, deer and dolphins, is sensitive to those criticisms. Autonomy is not the end-all, he said, but "the head of the battering ram" that can break through the legal wall separating humans from all other animals.

Once the wall is breached, said Wise, the discussion can change. "Right now, the question is, 'What species are you?' And if you're not human, you continue to be a legal thing, not a person," he said. "We can change that to, 'What sort of being are you? What sort of being is your species? Are you the kind of being who ought to have the potential for any rights at all? And if so, what rights are appropriate for you?"

Later this year, the Nonhuman Rights Project will argue their other chimpanzee lawsuits, which were also denied in lower courts. After that, they plan to file a lawsuit on behalf of an elephant and—if an appropriate sanctuary can be found—a cetacean, perhaps a captive bottlenose dolphin or orca.

Even if they're not successful in the courtroom, said Cassuto, the lawsuits have been useful in focusing public attention on the plight of these animals, and showing that the argument for personhood is based on sound legal and ethical principles.

"It's great that the question is being asked, 'Why should we put a chimp in a cage?' They are perfectly capable of understanding what a horrible situation that is," said Cassuto. "Why shouldn't they be free? The Nonhuman Rights Project is doing a great job of getting that across."

"I think we've made this respectable," said Wise. "Whether we win or lose today, we've already won."