There was no mistaking the diagnostic significance of that little red stick inside a deep blue cell: The Auer rod meant the mystery patient had acute myelogenous leukemia. As slide after slide went by, her bone marrow told a story: treatment, remission, relapse, treatment, remission, remission, remission.
I was reading these marrows in 1987, but the samples had been drawn in 1978 and 1979. Median survival of that lethal disease with treatment was about 18 months; however, given that she had already relapsed once, I knew that she had to be dead. Probably someone was being sued, and that was why my hematology colleagues had asked for a blind reading.
Imagining an aggressive cross-examination in court, I emphasized in my report that I knew neither the history nor why I was reading the marrows. After the work was submitted, I asked the treating physician what was going on. She smiled and said that my report had been sent to the Vatican.
This leukemia case was being considered as the final miracle in the dossier of Marie-Marguerite d'Youville, the founder of the Order of Sisters of Charity of Montreal and a candidate to become the first Canadian-born saint.
As in the case of Mother Teresa, who was canonized Sunday by Pope Francis, miracles are still used as evidence that the candidate is in heaven and had interceded with God in response to a petition. Two miracles, usually cures that defy natural explanation, are generally required.
The "miracle" involving d'Youville had already been overturned once by the Vatican's medical committee, unconvinced by the story of a first remission, a relapse, and a much longer second remission. The clerics argued that she had never relapsed and that her survival in first remission was rare but not impossibly so. But the panel and her advocates agreed that a "blind" reading of the evidence by another expert might provoke reconsideration. When my report confirmed what the Ottawa doctors found, that she had indeed had a short remission and then relapsed, the patient, who had prayed to d'Youville for help and, against all odds, was still alive, wanted me to testify.
The tribunal that questioned me was not juridical, but ecclesiastical. I was not asked about my faith. (For the record, I'm an atheist.) I was not asked if it was a miracle. I was asked if I could explain it scientifically. I could not, though I had come armed for my testimony with the most up-to-date hematological literature, which showed that long survivals following relapses were not seen.
When, at the end, the Vatican committee asked if I had anything more to say, I blurted out that as much as her survival, thus far, was remarkable, I fully expected her to relapse some day sooner or later. What would the Vatican do then, revoke the canonization? The clerics recorded my doubts. But the case went forward and d'Youville was canonized on Dec. 9, 1990.
That experience, as a hematologist, led me to a research project that I conducted in my other role, as a historian of medicine. Over hundreds of hours in the Vatican archives, I examined the files of more than 1,400 miracle investigations — at least one from every canonization between 1588 and 1999. A vast majority, 93 percent, were stories of recovery from illness or injury, detailing treatment and testimony from baffled physicians.
If a sick person recovers through prayer and without medicine, that's nice, but not a miracle. She had to be sick or dying despite receiving the best of care. The church finds no incompatibility between scientific medicine and religious faith; for believers, medicine is just one more manifestation of God's work on Earth.
Perversely then, this ancient religious process, intended to celebrate exemplary lives, is hostage to the relativistic wisdom and temporal opinions of modern science. Physicians, as nonpartisan witnesses and unaligned third parties, are necessary to corroborate the claims of hopeful postulants. For that reason alone, illness stories top miracle claims. I never expected such reverse skepticism and emphasis on science within the church.
I also learned more about medicine and its parallels with religion. Both are elaborate, evolving systems of belief. Medicine is rooted in natural explanations and causes, even in the absence of definitive evidence. Religion is defined by the supernatural and the possibility of transcendence. Both address our plight as mortals who suffer — one to postpone death and relieve symptoms, the other to console us and reconcile us to pain and loss.
Respect for our religious patients demands understanding and tolerance; their beliefs are as true for them as the "facts" may be for physicians. Now almost 40 years later, that mystery woman is still alive and I still cannot explain why. Along with the Vatican, she calls it a miracle. Why should my inability to offer an explanation trump her belief? However they are interpreted, miracles exist, because that is how they are lived in our world.
Jacalyn Duffin, a hematologist and historian at Queen's University in Canada, is the author of "Medical Miracles" and "Medical Saints." © 2016 New York Times