The Bronx Zoo's star attraction lives all alone in a one acre cage. The zoo calls it "Wild Asia". But an animal rights group calls it "cramped and lonely". 

Now, the Nonhuman Rights Project (NhRP) has failed in a bid to set Happy the elephant free. On Tuesday, New York's highest court rejected the organisation's claim that Happy is illegally detained. 

It is the end of an epic saga. Four years ago, lawyers for the NhRP filed a claim of unlawful detention, called a habeas corpusHabeas corpus petitions are usually used for people detained in jails or mental health hospitals. It is Latin for "produce the body".  petition, on Happy's behalf. They argued that legally, Happy and other emotionally intelligent animals should be people. Now, the ruling is in: under US law, Happy is not a personTo possess personhood is to hold certain rights and legal protections against cruel and unfair treatment.. 

"Habeas corpus is intended to secure the liberty rights of human beings who are unlawfully restrained, not nonhuman animals," wrote chief judge Janet DiFiore.

Judges feared that granting Happy personhood "would have an enormous destabilising impact on modern society". Our interactions with farm animals, service animals and even pets would all be called into question. 

Some philosophers even worry that if we start to treat intelligent animals more like humans, we might also start to treat some humans more like animals. 

But the court's ruling was not unanimousAgreed upon by everybody. . "Happy's captivity is inherently unjust and inhumane," wrote judge Jenny Rivera in her dissent. "It is an affront to a civilised society, and every day she remains a captive - a spectacle for humans - we, too, are diminished."

Happy did not always live in a cage. She was born in Thailand in the 1970s, wild and free. But less than a year later, she was flown across the Pacific, put in a polka-dot dress and forced to give rides to children. 

The NhRP believes that one day, we will look back at Happy's life with horror. There is no doubt: elephants are extraordinary creatures. They live in families, grieve for the dead and can both suffer and understand suffering. In 2005, Happy herself became the first elephant to pass the mirror testHappy repeatedly touched an X painted on her forehead, a place she could not see without a mirror. The test is a key indicator of self-awareness. . 

The philosopher Gary Varner argues that if personhood is defined as conscious awareness of one's past, present and future, then elephants "might be persons - or at least near-persons". 

It is not just elephants that have extraordinary abilities. Pigs can play computer games and hippos can identify each other's voices. 

For the NhRP, Tuesday's ruling is a setback. But the group is not giving up on the idea of personhood for animals. This February, Ecuador ruled in favour of a chorongo monkey's rightsThe things that you should be able to do or have in law. . And in 2021, the UK government introduced legislation to formally recognise animals as sentient beings. 

Already, there are plans to use Jenny Rivera's arguments in another elephants rights case in California. 

But for Happy, the appeals process is over. She will not move to a sanctuary to live out her final days. Yet many believe that the battle to fundamentally change the place of animals in both law and society is far from over.

Yes: Elephants are incredible creatures. For years, they have faced suffering at the hands of humans. Granting elephants human rights would ensure they are given the respect they deserve.

No: This is a preposterous idea. Elephants may be intelligent, but they do not have the same capabilities and responsibilities as people. Human rights should be reserved for humans.

Or... Elephants are not people, but that does not mean they do not deserve dignity and respect. We should draw up new laws to protect the rights of emotionally complex animals.