FOR TOO LONG I have known doctors who work on$ dying patients but won't work with dying patients. They know modern medicine but they are unmodern healers. They see death as defeat and dying patients as losers. It isn't only lunkhead football coaches for whom winning is everything. This ravenous ethic pervades hospital corridors, too.

Occasionally a doctor walks through those corridors who has the soulfulness to understand the futility of mortal combat with mortality. One of these is Dr. Frances Sharkey, a pediatrician for some 20 years who is now in group practice in Sunnyvale, California.

She is not a professional writer, but her offering of direct and unclouded prose carries us deep into the nobility of the medical vocation as few doctors have ever explored it and few books have ever revealed it.

The superior passages of A Parting Gift are unaffectedly stark in portraying the wrongheadedness of those doctors who deny death. But the enduring superiority is the confrontation that this gifted doctor has with herself. Its telling is free of overbrooding, expressed with pith and in the end uplifting, as any story of self-liberation naturally is.

Dr. Sharkey begins in the late 1950s. As a second-year medical student, her first patient was a 92-year-old woman, in the last unpreventable agonies of heart failure. This first patient became Dr. Sharkey's first death.

She recalls other medical school encounters. On the daily rounds one morning, a professor wouldn't take the students in to see a man with advanced cancer. "Let's not disturb him," the professor said. "The patient is understandably depressed. There is no need for us to intrude on his privacy."

Recalling these flybys, Dr. Sharkey writes: "We sincerely thought we were being considerate by not intruding when there was nothing more we could do. This made me uneasy and sad, but it never occurred to me that dying people might want to hold onto anything that could temporarily interrupt their deepening estrangement from life. When death became unavoidable, it was always a relief to find that the dying patient was religious; we could turn the person over to a priest, who would fill a need that we knew we could not."

After her fourth year, Dr. Sharkey was accepted for a pediatric internship. Even though she had learned well how to be the prim and properly controlled doctor when death (defeat) loomed, "caring for dying patients was the part of medicine I hated. Life and nature were on the side of the pediatrician."

Taken for granted this way, nature threw something back at the young doctor: a few months of residency in a cancer ward for children. Following the death of a 15- year-old girl, the child's mother thanked Dr. Sharkey for her empathy. "What she said sounded nice," the doctor writes, "but as I heard her words, I felt like a hypocrite. True the sedation I ordered did prevent pain, but my main reason for sedating the children was that I did not want them to know they were dying. No one ever realized this. Many parents wrote me moving letters after their children died, but in spite of their thanks I knew something was wrong. I was robbing the children of their last days in the name of kindness. Was it really the right thing to do?"

As though a slave uprising was occurring in her soul-- so many bondages to professional aloofness demanding freedom--Dr. Sharkey tells of asking a hospital death- and-dying counselor for help. She was given it, along with a book of Elisabeth Kubler-Ross, the psychiatrist who examined the feelings of dying patients.

But the restraints didn't fall easily. When a cancer- ridden child was near death, the doctor reached over the bed to grasp the wasted body: "My God, I thought in a near panic, this isn't what you're supposed to be doing, holding a dying patient in your arms."

Nearly half of A Parting Gift explores the relationship between Dr. Sharkey and David, a 21/2-year-old boy brought to her with leukemia. After treatment with some of the standard drugs--Prednisone, Vincristine-- the anti-cancer therapy appeared to be working. To tell here of the eventual outcome of David's case would be to sap the drama found in the gripping final pages. David dies, but where, how, under what circumstances and what his parting does to his family and doctor, are details told artfully. If tears come to a reader's eye, they are ones of gratitude for Dr. Sharkey's medical wisdom and compassion, not tears jerked by the maudlin. Nothing of the latter is here.

Should she want a second career, or need a sabbatical, I suggest Dr. Sharkey become a traveling lecturer at the nation's medical schools. The young doctors coming on need to spend less time dissecting cats and cadavers and more of it cutting through the layered fears and denials of death that have lately taken over American medicine.

Dr. Sharkey's message may not be what the doctor ordered. It's better. It's what the patients are ordering.