Reflecting on the legacy of French geneticist Jérôme Lejeune, Pope Leo XIV said no physician should be permitted to decide whether an embryo or elderly person lives or dies based on calculations of utility or efficiency.
The Holy Father made the remarks during a June 22 audience with members of the Jérôme Lejeune Foundation, gathered at the Vatican to mark the centenary of the scientist's birth.
Pope Leo's address focused on the life and legacy of Venerable Jérôme Lejeune, a Catholic French geneticist who discovered the chromosomal abnormality responsible for Down syndrome and later became a prominent advocate for unborn children and those with disabilities. He denounced the use of his discovery to identify and eliminate children with Down syndrome before birth as a "new eugenics" and "chromosomal racism.”
"He did not hesitate,” Pope Leo said, “to become their defender.”
Reflecting on Lejeune's example, the Pope emphasized that the value of a human person does not depend on achievement, autonomy, or social usefulness.
"For this reason,” the Holy Father said, “a physician should never be allowed to decide of the life of a particular embryo or a particular elderly person, on the basis of laboratory algorithms!”
The Pontiff also warned that technology, while capable of assisting medicine, should never replace the ethical responsibility to protect human life and dignity.
"Medicine,” he said, “must never become the servant of programmed death!”
The Pope also recalled Lejeune's conviction that medicine is rooted not only in combating disease but also in caring for the person who suffers from it, describing the physician as a man who devotes himself to the “poorest of the poor.”
Concluding his remarks, Pope Leo encouraged the foundation to continue its work in research, patient care, and the defense of human dignity, urging its members to be "committed witnesses in society" in service of the common good.