“What is it you don’t understand? She’s dead, dead, dead.” That is how David Durand, chief medical officer of the Children’s Hospital in Oakland, California, attempted to convince the family of Jahi McMath that the standard medical tests for brain death had shown that their teenage daughter was no longer alive.

The family stood firm in opposing this view and the hospital eventually allowed them to take her to New Jersey, the only U.S. state that requires hospitals to accommodate patients whose families object, on religious grounds, to regarding brain death as death. For more than four years, she remained a functioning (though radically disabled) member of the species Homo sapiens: fighting off infections, reacting to bodily trauma by increasing her heart rate and getting her first period.

McMath’s case revived interest in (and debate over) what it means to die. A few years earlier there appeared to be a consensus that brain death is death. But if such a consensus ever existed, it no longer does.