Dr. C. Everett Koop, who served as the U.S. Surgeon General under President Ronald Reagan in the 1980s, died today at 96 years old.

Dr. Koop was a true hero and a great American, and it is hardly disputable that many Americans alive today owe their lives and their health to him. In fact, the nearly ubiquitous expectation of condom use today, in order to prevent the spread of disease, can be traced directly to Dr. Koop and his extremely visible advocacy of safe sex.

Safe sex may seem like a no-brainer today, but in the 1980s, when social conservatives were feeling their oats—with one of their own in the White House and the so-called “Moral Majority” becoming a political force—it took real courage for Dr. Koop to lead a public crusade for the usage of condoms.

It was a real surprise to just about everybody that Dr. Koop would lead this crusade. A deeply religious, devout, conservative Christian, he considered homosexuality, non-marital sex and abortion to be morally wrong. I could not disagree more with his point of view on these issues. And yet, the fact that he was able to put his views, and the pressure of his ideological peers, aside and go where the facts led him—that is what elevated Dr. Koop to a true national treasure.

Confronted with the AIDS epidemic, which at that time was largely seen as a “gay plague,” those who supported Dr. Koop’s appointment expected him to condemn homosexuality and advocate sexual abstinence. Dr. Koop instead launched his public crusade in which he worked tirelessly to educate the public that the safest way to have sex was to use a condom every time.

Dr. Koop did not simply issue a report and leave it at that. He all but shouted it from the rooftops, using his office as a very public, very visible platform to spread the word across the country and the world. And it worked. When the 1980s began, condom use in non-marital, sexual relationships was by no means a given, particularly among gay couples, or among straight couples in which the female was on the pill. By the time I graduated high school in 1990, it was well understood that if you planned to have sex, you needed to use a condom. In terms of public health, there are probably two things anybody alive at the time remembers: “Just say no (to drugs),” as Nancy Reagan told us; and “Use a condom every time,” courtesy of Dr. Koop.

Additionally, Dr. Koop suggested that children receive comprehensive sex education starting in elementary school, which is still—unfortunately—a controversial issue today, nearly 30 years later. And, in another service to public health, he took on Big Tobacco and promoted the idea of a smoke-free society. We are not there yet, but every year, fewer and fewer Americans are engaging in this risky behavior.

And while Dr. Koop never veered from his belief that abortion was murder, he also refused to cave in to pressure from the right and endorse errant, pseudo-scientific theories that abortion would cause lasting harm to women who underwent one. It is a pity that there are those today who do not have the courage or the wisdom to follow his example.

In a time when it has become increasingly unlikely for those with strong viewpoints to overlook those views, and do what is necessary to save lives and improve public health, Dr. Koop stands as a beacon of reason, courage, and rectitude. Dr. Koop did the right thing for his country and his fellow human beings, even though he undoubtedly disapproved of the actions that made his condom crusade necessary. Despite his beliefs, he was right in his actions. I believe history will record that Dr. C. Everett Koop was one of the most influential and consequential human beings of the 20th century.

In matters of religion, I am an agnostic. I don’t know if a god exists, and frankly, I don’t care. But if the God in which Dr. Koop believed devoutly all his life does exist, and the good doctor has, in fact, met his maker today, I am confident that this divine being has welcomed Dr. Koop warmly, and congratulated him on a job well done.

Godspeed, Dr. Koop. Thank you for a life of service unmatched by almost anyone alive today.