Editor's note: Danny Cevallos, a CNN legal analyst, is a criminal defense attorney practicing in Philadelphia, St. Thomas and St. Croix.  (CNN) -- 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.  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.  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.  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.  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?  Follow us on Twitter @CNNOpinion.  The opinions expressed in this commentary are solely those of Danny Cevallos.
Danny Cevallos says judges and lawyers are wary of the claim, but lawsuits make a plausible claim that nonhuman creatures can legally be considered persons