Many members of today's graduating class reacted to the news that I would give this year's Commencement Address just as I did: with surprise. The Harvard Crimson recorded some undergraduate responses: "Who is he?" "Wow, that's boring. Everyone else got someone exciting." Editorials criticized the process by which "Dr. Who" was selected. I was featured in entertaining cartoons, something that hasn't happened during three years in Washington. I may never be this famous again.

There is an advantage to starting from low expectations. Agreed, I am not running for President, and I am not a prime minister or a general. But I speak for an element of our culture at least as important as politics or war. That element is science.

The products of science shape and pervade our lives. Sir Francis Bacon made this point in 1620. "Printing, gunpowder, and the magnet," he wrote, "have changed the whole face and state of things throughout the world...no empire, no sect, no star seems to have exerted greater power and influence in human affairs." Modern equivalents are legion: consider e-mail, nuclear weapons, biotechnology.

I will speak today about the effects of science on our lives. But I will emphasize science in its most fundamental form, the process by which we make discoveries about the world--like the atom or the gene--that precede practical inventions. At its core, science is a way of thinking--making judgments, often creative ones, that are based on evidence, not on desires, received beliefs, or hearsay. Thinking in this way is not unique to the natural sciences; it is important for many disciplines. But the pursuit of evidence, through experiment and observation, is the lifeblood of science.

Like many physician-scientists of my generations, I learned to do and to love research while working at the National Institutes of Health, the Federal agency that supports most of the basic medical research in this country. I arrived at the NIH as a 28-year-old doctor seeking two things: the credentials to become a medical school professor and an alternative to service in Vietnam. Then, one day some months later, I was abruptly transformed into a committed scientist when a method I was developing to detect expression of a gene suddenly worked. At that moment, I knew the intoxicating power of measurement and the sweet anticipation of my own results.

I enjoyed many measurements and many results. Despite the common myths about science, it was not lonely work. Much of the pleasure came from companionship. Most of our experiments lacked discernable practical goals. We followed our hunches, working with cancer viruses from chickens and mice, supported largely by grants from the NIH. Eventually, over many years, patterns emerged. We had learned that cancer genes in viruses are derived from normal cellular genes--some of the genes that guide our growth and development. These genes, now called oncogenes, undergo the mutations that are the defining events in cancer. Obscure viruses from experimental animals had in this way allowed us to touch directly the heart of human cancer. A path to understanding has been opened.

Like researchers in all fields, I have also known disappointment, boredom, surprise and even irony. One example was especially instructive. The painful reality of cancer has always loomed in the background of my work, because my mother and her mother died of breast cancer. For this reason, my lab studied for many years a virus that causes breast cancer in mice, in hopes of finding relatives of human breast cancer genes. Ultimately, we discovered interesting genes that guide formation of the brain and other organs. But, in this case, they don't appear to be involved in human cancer of any kind. There is no simple road map for this kind of research.

Every morning, on the way to my office, I cross the portico from which Franklin Roosevelt dedicated the first NIH buildings on a late fall day in 1940. His paralyzed legs braced with metal, his energies worn down by his third Presidential campaign, his mind focused on the World War already being waged in Europe, FDR made a powerful statement about medical research:

"The total defense, which this Nation seeks, involves a great deal more than building airplanes, ships, guns and bombs. We cannot be a strong Nation unless we are a healthy Nation. And so we must recruit not only men and materials but also knowledge and science in the service of national strength."

Roosevelt's optimism about medical research seems, in retrospect, amazing. Doctors could not prevent or treat the poliovirus infection that had paralyzed him nearly twenty years earlier. John Franklin Enders and vaccines were still in the future; the main therapies were iron lungs and warm baths. Most of the staples of modern medicine were also still unknown. Antibiotics. Hormone replacements. Effective drug therapies for psychotic illnesses. Pre-natal testing. Coronary bypass surgery and artifical joints. Also in the future were medications that could have lowered FDR's blood pressure and perhaps forestalled the stroke that killed him less than five years later, at the now relatively young age of sixty -three.

Still, FDR's optimism proved to be justified. Even before the War was over, the chemical synthesis of quinine improved treatment for malaria in the pacific theatre, and the manufacturing of Fleming's penicillin effectively controlled wound infections for the first time in the history of war-fare. Following the War, inspired by these successes, the Federal government made unprecedented investments in many fields of science, through the NIH and other agencies. These investments have been essential for the vitality of American science ever since.

The patient told us how he was rescued from death by a kidney transplant at the age of ten, gradually lost his vision, and has lived with chronic pain. Senator Kennedy asked whether he had brothers and sisters. The patient replied, quite matter-of-factly, that two older brothers had died from the disease when he was very young, because kidney transplants were not yet available. So he felt fortunate to have been born recently enough to benefit from a life-saving transplant. The patient was also glad that affected children born yet more recently could avoid the kidney disease altogether; a recently developed medication prevents formation of the crystals altogether. A few minutes later a normal looking, 11-year-old boy who had inherited the same disorder bounded into the room and spoke animatedly about sports, hobbies, school--and about the unpleasant taste of the medicine he had been taking nearly all his life.

This episode embodies many of my messages today: the message that science can improve lives in ways that are elegant in design and moving in practice; that the Federal government, much maligned in current politics, can be a powerful force for public benefit; that the government can work productively with universities, where the cellular defect in cystinosis was studied, and with industries, where the new drug was manufactured; and finally, that progress in medical science occurs at a pace that may seem slow at the time to desperate parents, but astoundingly rapid in retrospect. Just consider: in the space of a generation, this lethal disease was made survivable with transplants, then curable with drugs.

FDR knew what we needed: "All of us are grateful that we in the United States can still turn our thoughts and our attention to those institutions of our country which symbolize peace--institutions whose purpose is to save life and not to destroy it."

FDR's confidence then underscores the dilemmas that now plague us in the aftermath of the Cold War. The Federal government is broke and under attack by its own citizens. Universities and colleges are more strapped for funds than ever before. And many industries are turning away from research investments.

Dr. Who is not the person who can solve these problems. Instead I hope to recruit you to my passions: that our institutions must be fit to nurture talent., that new talent is essential to advance science and that science, a source of beauty and delight, is also our best hope of fighting the threats of Alzheimer's and many other diseases.

Several hundreds of you graduating today have already enlisted in these battles, as future scientists or physicians. But the battle does not engage only those on the front lines. It will affect all of you. As worried patients, parents, and caretakers of parents. As taxpayers and good citizens of the world. And as thoughtful Harvard graduates, who know that science--like "no empire, no sect, no star" --can eventually change "the whole face and state of things throughout the world."