There's a battle heating up in New York State courts, and it's a question over how we define "personhood."
Tommy the chimpanzee, alongside three other chimps, are suing their captors in order to prove that they are not things, but persons. As persons, these chimpanzees have the right not to be imprisoned without good reason.
It's a fight that's being led by Steven Wise, president of the Nonhuman Rights Project and the lawyer representing the chimps.
Wise says science proves that these apes, alongside elephants, cetaceans like dolphins and whales, and African grey parrots, are among a class of nonhuman animals that exhibit high cognitive ability. They're self-aware, they experience pain and joy and they suffer terribly from confinement.