Update (July 28, 2026): Made minor editorial revisions for clarity and readability. No material changes were made to the reporting or analysis.
The Michigan Supreme Court declined on Friday, July 17, 2026, to hear an appeal seeking a writ of habeas corpus on behalf of seven chimpanzees confined at the DeYoung Family Zoo, leaving intact a published Court of Appeals decision holding that chimpanzees are not legal persons entitled to invoke one of the oldest protections of the common law. The Court denied review without further explanation, stating only that it was “not persuaded that the questions presented should be reviewed by this Court.”
Justice Elizabeth M. Welch, a member of the species Homo sapiens and the same great ape family, Hominidae, as the chimpanzees at the center of the case, was among the primates dissenting.
In seven pages of carefully ordered visual symbols on paper, a form of symbolic communication nonexclusive to Homo sapiens, she argued that the Court should have taken the case to consider whether modern scientific understanding of chimpanzees warrants reconsidering who may seek habeas corpus under Michigan common law.
The distinction is important because the lawsuit never argued that chimpanzees are human beings. Instead, the Nonhuman Rights Project argued that chimpanzees possess a common law right to bodily liberty and asked a court to determine whether their confinement is lawful. The organization sought an order requiring the zoo to show cause why the chimpanzees' confinement was lawful. Ultimately, it asked the court to order the animals transferred to an accredited chimpanzee sanctuary where they could live, to the greatest extent possible, as autonomous beings.
The legal vehicle for that request was a writ of habeas corpus, a Latin command meaning "you shall have the body." For centuries, habeas corpus has allowed someone held in custody to ask a court whether that confinement is lawful. It does not guarantee release. It guarantees that one member of a community may require the community to justify a confinement.
Justice Welch begins not with constitutional theory but with science. She summarizes evidence presented by the parties and supporting friend of the court filings that chimpanzees possess autonomy, self-awareness, empathy, foresight, compassion, and the capacity to grieve. She recounts the story of Bruno, a chimpanzee whose interaction with a researcher has become a widely discussed passage of the case.
Bruno is not one of the chimpanzees housed at the DeYoung Family Zoo. According to court filings, before entering a laboratory, Bruno had learned signs. When Bodamer met him 16 years later, he had gone all that time without any sign-language communication, recognizing none of the laboratory staff were able to read basic signs. Justice Welch recounts an encounter between Bruno and researcher Dr. Mark Bodamer that has become one of the most discussed passages of the opinion.
Bodamer asked Bruno a seemingly simple question.
“What is your name?”
Bruno answered a different question.
Instead, he signed, “KEY OUT.”
Believing he had misunderstood, Bodamer asked him to repeat himself. Bruno turned toward him, lifted his hands so they could be seen more clearly, and signed again, “OUT. KEY. OUT.”
There was no ambiguity about the subject he wished to discuss.
He then crouched beside the door of his cage and repeatedly signed “OUT,” growing visibly more excited each time.
Bodamer later recalled his response.
“I signed back CAN’T SORRY CAN’T. Bruno’s shoulders dropped, and he walked to the back of his cage, crestfallen.”
Justice Welch does not present the episode as sentiment.
“Based on the evidence presented,” she writes, “chimpanzees appear unsuited for confinement.”
The Court of Appeals viewed the case differently.
Its published opinion concluded that chimpanzees are not legal persons because they cannot participate in the reciprocal obligations of the social contract. In reaching that conclusion, the court relied upon William Blackstone’s description of humanity’s “despotic dominion” over animals and upon the political philosophy of Thomas Hobbes. Because chimpanzees are not voluntarily and consciously surrendering part of their natural liberty in exchange for the protections of the human-centric form of civil society, the court concluded that they cannot invoke habeas corpus.
Justice Welch challenges both the history and the logic of that reasoning, arguing that rather than merely aping inherited assumptions, courts should confront the facts and evidence before them, both scientific and human.
The dissent examines the historical foundations of the Court of Appeals’ reasoning. Standing behind much of that reasoning was the English jurist who wrote under a monarchy that elevated one human above millions of others through the superstition of inherited authority. Precisely the species of elaborate political charade that the ongoing 259-year-and-counting American Revolution forcefully declares incompatible with the equal dignity of mankind since its beginnings in response to British Parliament’s 1766 Declaratory Act, which asserted illegitimate authority to legislate for the colonies “in all cases whatsoever,” effectively claiming that one population of a primate species could acquire a moral right to command another without their consent.
Consistent with that historical foundation, the Court of Appeals relied on Blackstone’s description of “despotic dominion,” a phrase he used in discussing the Abrahamic account of creation, to support its conclusion that nonhumans are property rather than legal persons. The opinion thus turned, in part, on words written before the discovery of DNA, before slavery was abolished, before Darwin, before women could vote, before modern primatology, before electricity, before the moon landings, before Stonewall, before the internet, and before anyone had observed a chimpanzee intelligibly ask a human for a key using another species’ symbolic language. A significant demonstration of intentional interspecies intelligence that Homo sapiens has yet to answer with comparable competence.
Justice Welch questions whether this centuries-old conception of dominion should continue to guide Michigan common law. She notes that many theologians reject that understanding of biblical dominion, arguing that it describes stewardship rather than domination, and cautions that courts should not rely on the concept of dominion to justify the subjugation of living beings. She also observes that similar reasoning has historically appeared in legal doctrines used to justify a denial of the rights of Native American nations.
As a matter of her dissent, she concludes that the Court of Appeals’ social contract analysis proves too much. If the ability to assume legal duties determines who may seek habeas corpus, then the principle excludes not only chimpanzees but many human beings incapable of recognizably entering a social contract. Human infants arrive with no greater appreciation of Hobbes than chimpanzees, yet no court would conclude that such individuals are therefore excluded from the protection of the writ of habeas corpus. For Justice Welch, the difficulty is not merely philosophical. It is practical. “That logic must, of course, fail,” she signs.
Whether chimpanzees should ultimately prevail remains an open question because the Michigan Supreme Court declined to answer it. Justice Welch did not argue that the seven chimpanzees must be released. She argued that the Court should have heard the appeal and considered whether the common law understanding of habeas corpus should evolve in light of much more modern understandings.
Her concluding observation places the case within a broader historical tradition. Quoting both earlier precedent and the United States Supreme Court, she notes that history has repeatedly expanded humanity’s circle of moral concern and reminds readers that “times can blind us to certain truths and later generations can see that laws once thought necessary and proper in fact serve only to oppress.”
For now, the seven chimpanzees at the DeYoung Family Zoo remain where they are, and the Court of Appeals’ decision remains controlling law in Michigan.
The constitutional question raised by the case, however, has not disappeared. Justice Welch’s dissent leaves behind a question. If a consensus establishes that another living being understands a loss of liberty, should communities refuse even to ask why that liberty is being taken away?
Not often (well, since starting SSRIs) am I moved to tears by a piece of writing, but this one really got me. Excellent framing and analysis, but also incredibly incisive and powerful work to highlight this story that I think everyone should read. Thank you for the great work!!