Update, 21 April: Science has learned that the court order referred to in this story has been amended. The words “writ of habeas corpus” have been struck out, suggesting that the court has made no decision on whether Hercules and Leo—two research chimpanzees at Stony Brook University in New York—deserve to be treated as legal persons. The Nonhuman Rights Project has responded to the amendment, stating, “This case is one of a trio of cases that the Nonhuman Rights Project has brought in an attempt to free chimpanzees imprisoned within the State of New York through an ‘Article 70-Habeas Corpus’ proceeding. These cases are novel and this is the first time that an Order to Show Cause has issued. We are grateful for an opportunity to litigate the issue of the freedom of the chimpanzees, Hercules and Leo, at the ordered May hearing.” Stony Brook has also issued a statement about the case: “The University does not comment on the specifics of litigation, and awaits the court's full consideration on this matter.” 
 
 Update, 22 April: The court hearing has been moved back from 6 May to 27 May. At that time, the judge will hear legal arguments regarding whether Hercules and Leo should remain at Stony Brook. 
 
 In a decision that seems to recognize chimpanzees as legal persons for the first time, a New York judge today granted a pair of Stony Brook University lab animals the right to have their day in court. The ruling marks the first time in U.S. history that an animal has been covered by a writ of habeas corpus, which typically allows human prisoners to challenge their detention. The judicial action could force the university, which is believed to be holding the chimps, to release the primates, and could sway additional judges to do the same with other research animals. 
 
 “This is a big step forward to getting what we are ultimately seeking: the right to bodily liberty for chimpanzees and other cognitively complex animals,” says Natalie Prosin, the executive director of the animal rights organization, the Nonhuman Rights Project (NhRP), that filed the case. “We got our foot in the door. And no matter what happens, that door can never be completely shut again.” 
 
 Richard Cupp, a law professor at Pepperdine University in Malibu, California, and a noted opponent of personhood for animals, cautions against reading too much into the ruling, however. “The judge may merely want more information to make a decision on the legal personhood claim, and may have ordered a hearing simply as a vehicle for hearing out both parties in more depth,” he writes in an e-mail to Science. “It would be quite surprising if the judge intended to make a momentous substantive finding that chimpanzees are legal persons if the judge has not yet heard the other side’s arguments.” 
 
 The case began as a salvo of lawsuits filed by NhRP in December 2013. The group claimed that four New York chimpanzees—Hercules and Leo at Stony Brook, and two others on private property—were too cognitively and emotionally complex to be held in captivity and should be relocated to an established chimpanzee sanctuary. NhRP petitioned three lower court judges with a writ of habeas corpus, which is traditionally used to prevent people from being unlawfully imprisoned. By granting the writ, the judges would have implicitly acknowledged that chimpanzees were legal people, too—a first step in freeing them. 
 
 The judges quickly struck down each case, however, and NhRP has been appealing ever since. Today’s decision is the group’s first major victory. In her ruling, New York Supreme Court Justice Barbara Jaffe orders a representative of Stony Brook University to appear in court on 6 May to respond to NhRP’s petition that Hercules and Leo “are being unlawfully detained” and should be immediately moved to a chimp sanctuary in Florida. Both animals have been used to understand the evolution of human bipedalism. (Stony Brook did not immediately respond to a request for comment.) 
 
 Prosin says that even if NhRP loses the case, it will use the habeas corpus ruling to sway judges in other jurisdictions. “It strengthens our argument that these nonhuman animals are not property,” she says. The group plans to file another case—this one involving a captive elephant—by the end of the year and has set its sights on other animals, including research animals, across the country. “We have the scientific evidence to prove in a court of law that elephants, great apes, and whales and dolphins are autonomous beings and deserve the right to bodily liberty,” she says. 
 
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 Perhaps history will not remember me kindly. Perhaps I will be a reminder of an oppressive era, a warning to future generations of small-mindedness in a grainy photograph. Perhaps I'm a dinosaur. Why? 
 
 Recently, an animal rights group, the Nonhuman Rights Project (NhRP) filed a habeas corpus petition on behalf of a oppressed chimpanzee ... and my reaction was: Are. You. Kidding. Me? 
 
 Since that time, three habeas petitions the group filed have been thrown out by their respective courts, but not before they sparked a nationwide debate about whether animals are entitled to the elusive status of "personhood." 
 
 Animals are chattels. That's what is drilled into the heads of law students, at least. Chattels are personal property, and personal property can be living or nonliving, like livestock or a potted plant. Chattels do not have rights. Or do they? 
 
 When the story first surfaced, like many doubters, I tracked down one of the petitions, ready to level some harsh criticism. 
 
 Danny Cevallos 
 
 I read the petition . And, I have to grudgingly admit: Their arguments are persuasive. 
 
 The NhRP, which claims to be the only group fighting for actual legal rights for animals, filed this petition on behalf of Tommy, a chimpanzee being "held" in a cage by his owners who run a reindeer farm in Gloversville, New York. 
 
 First, some background: 
 
 A writ of habeas corpus requires a person under arrest to be brought before a judge or into court. The idea behind habeas corpus is to provide a mechanism to seek the release of an unlawfully detained prisoner who is being held without sufficient cause or evidence. 
 
 Habeas petitions presumptively only apply to persons. So, if law enforcement seizes my Grandpa Vito's 1971 Ford Pinto because of his suspected drug dealing, he can't bring a habeas petition to release the unlawfully detained car. He could possibly get it back from the government, but not with a habeas petition. 
 
 JUST WATCHED Wildfires a close call for chimps Replay More Videos ... MUST WATCH Wildfires a close call for chimps 02:29 
 
 If you scoffed at the idea of property having rights, what would you say to the fact that successful habeas petitions have been brought on behalf of property in the past? There is precedent, found in the more scandalous annals of American history: slavery. 
 
 The most famous habeas corpus case in pre-Civil War America was that of the slave Dred Scott, who attempted to sue for his freedom. The U.S. federal court granted this petition for a writ of habeas corpus, which was upheld by the court of appeals. Once it got to the Supreme Court, however, things went badly for Scott. The court held that Scott, as property, was not a "person" within the purview of the Constitution. 
 
 Even though the Dred Scott decision is rightly cited as an example of racial injustice, it was also viewed as an example of a habeas petitions brought by "property" lacking "personhood." In light of this regrettable history, the Nonhuman Rights Project makes a creative historical argument: there is legal precedent for habeas petitions filed by beings considered both nonpersons, and property. 
 
 There's more. 
 
 In a way, the law does recognize animals as persons already. If your Aunt Edna left her fortune to her cat, then that's an example of recognizing animals as beneficiaries of trusts. Not surprisingly, the Nonhuman Rights Project has strategically set up a trust with Tommy the Chimp as a beneficiary, which they argue bolsters their position that he is a person within the law. 
 
 If you're still skeptical, would you be more inclined to believe that a chimp should be considered a person if I told you that the law already recognizes as persons things that are not even living? 
 
 The Supreme Court's holding in Citizens United paved the way for corporate "personhood" and the idea that corporations are free to exercise the First Amendment rights historically held only by humans. 
 
 So there appears to be some legal support for the position that a chimpanzee can bring a habeas petition, but the question remains: Are chimpanzees enough like humans that they qualify for personhood? In fact, how do we even define a person? It's a deep philosophical question as well as a scientific one. 
 
 According to the petition, the most important cognitive ability in determining personhood is autonomy, which appears to be the establishment of an independent set of values, opinions and beliefs. This is supported by a laundry list of specific cognitive abilities, including empathy, self-knowing, imagination, sequential learning and a host of other sophisticated attributes that I'm quite certain some members of my own family do not exhibit. Leading primatologists, whose affidavits are attached to the petition, assert that chimpanzees demonstrate substantial cognitive abilities. 
 
 Of course, the obvious "slippery slope" argument against the petition is "where does it end"? Could this lead to habeas petitions for hedgehogs? Goldfish? iPads? 
 
 Yet another problem not even raised by the petition is this: however you define autonomy, it appears that an adult chimpanzee possesses more cognitive abilities as described in the petition than certain humans, such as a newborn baby, or an adult in a persistent vegetative state. In the case of a newborn human baby, while she may be less autonomous than an adult primate, she will, in time, overtake a primate in cerebral sophistication. So, it seems we define humanity not just by the then-attributes of an infant, but in that infant's potential. 
 
 But defining personhood by cognitive ability presents a problem in the case of the adult person in a coma, or a persistent vegetative state. If we define personhood by autonomy and cognition, are unfortunate humans such as Terri Schiavo somehow stripped of their personhood because they no longer exhibit sufficient brain activity? Our society and law appears to answer that question with a resounding no. 
 
 As for the Nonhuman Rights Project, their next step is the appellate courts. They may fare better there; the appellate courts may be more likely to consider completely the supporting science of the proffered primatologists. If the appellate court does so, and reviews the issues of law anew, all hope is not lost for Tommy and his brethren. 
 
 Where do you draw the line for personhood? 
 
 Is it reserved for the human race only? Or will viewpoints like these be viewed as old-fashioned in the future? Will Tommy be remembered as the face of a new rights movement? 
 
 Or, is he just property?
– The writ of habeas corpus lets prisoners appear in court to make their captors justify why they're being held. Until now in the US, those who've used this legal tactic have been human. But a New York judge yesterday ruled that the writ may be used by two lab chimpanzees at Stony Brook University, Science magazine reports. NY Supreme Court Justice Barbara Jaffe ordered a university rep to address a suit filed by the Nonhuman Rights Project by appearing in court May 6 to argue why the college is holding Hercules and Leo. The group, which says the animals are being detained for biomedical experiments, says its ultimate goal is to have the animals released to the Save the Chimps sanctuary in Fort Pierce, Fla., per the NhRP's website. "This is a big step forward to getting what we are ultimately seeking: the right to bodily liberty for chimpanzees and other cognitively complex animals," Natalie Prosin, the project's executive director, tells Science. The case kicked off in December 2013 with lawsuits that also included two chimps held on private property; each case was struck down, sending the NhRP down the appeals path. Not everyone's convinced the upcoming hearing will mean liberation for the chimps. A Pepperdine University law professor tells Science that the judge likely just wants to hear both sides of the story: "It would be quite surprising if the judge intended to make a momentous substantive finding that chimpanzees are legal persons" without doing so, he notes. Prosin, meanwhile, says her group isn't stopping with the chimps and will also target the release of other animals. (Click to read about what chimps talk to each other about.)