Though courts sided with the parents, Dr. Koop spoke out against the parents’ decisions in both cases, saying that the medical and legal establishments had a duty to protect citizens against neglect and discrimination, no matter their age, and that a government’s authority to override the rights of parents had been established in truancy law and in child abuse and immunization laws. (Baby Doe died while the case was being appealed to the United States Supreme Court; Baby Jane Doe survived, though a delay in treatment was believed to have contributed to her severe retardation.)

Dr. Koop often said that his Presbyterian faith had helped him and his wife cope with the death of his 19-year-old son, David, who was killed in 1968 when a cliff gave way while he was climbing in New Hampshire. Dr. Koop and his wife wrote about the loss of a child in “Sometimes Mountains Move,” published in 1974.

Dr. Koop’s religion was also central to his opposition to abortion, which he considered a violation of divine principle. But once in public office, he said, he found it necessary to declare — to the disappointment of the White House — that evidence did not support the contention that abortions were essentially unsafe. In taking that position, he later said, he was being naïve. He had failed to realize that the Reagan administration expected him to oppose abortion zealously, he wrote in his 1991 autobiography, “Koop: The Memoirs of America’s Family Doctor.” And in an interview for this obituary in 1996, he said he had declined to speak out on abortion because he thought his job was to deal with factual health issues like the hazards of smoking, not to express opinions on moral issues.

Abortion presented little health hazard to women, he said, so it was a moral and religious matter, not a health issue.

Taking On Big Tobacco

Dr. Koop said he had begun campaigning against smoking after studying the research into its link to cancer, heart disease, stroke and other diseases. He was “dumbfounded,” he said, “and then plainly furious at the tobacco industry for attempting to obfuscate and trivialize this extraordinarily important public information.”

In taking on the tobacco lobby, he was also taking on powerful politicians from tobacco-growing states. After Dr. Koop accused the industry of directing advertising at children and threatening human lives, Gov. Jim Hunt of North Carolina, a Democrat, called for his impeachment, and Senator Jesse Helms, Republican of North Carolina, tried in vain to have Congress investigate him.