BETHESDA, Md. – The pedigree of human beings, Lewis Thomas wrote, probably traces to a single cell fertilized by a lightning bolt as the Earth was cooling.

Fortunately, genetic “mistakes” — mutations — eventually made us. But they also have made illnesses.

Almost all diseases arise from some combination of environmental exposures and genetic blunders in the working of DNA. Breast cancer is a family of genetic mutations.

The great secret of doctors, wrote Thomas — who was a physician, philosopher and head of the Memorial Sloan-Kettering Cancer Center — “is that most things get better by themselves; most things, in fact, are better in the morning.” But many things require intelligent interventions — cures.

So, to see the federal government at its best, and sequester-driven spending cuts at their worst, visit the 322 acres where 25,000 people work for the National Institutes of Health.

This 60th anniversary of the Clinical Center, the NIH’s beating heart, is inspiriting and depressing: Public health is being enhanced by NIH-supported research here, and in institutions across the country, into new drugs, devices and treatments.

Yet, much research proposed by extraordinarily talented physicians and scientists cannot proceed because the required funding is prevented by the intentional irrationality by which the sequester is administered.

A 2 percent cut in federal spending would be easily manageable. It has, however, been made deliberately dumb by mandatory administrative rigidities intended to maximize pain in order to weaken resistance to any spending restraint.

Spending on basic medical research is being starved as the river of agriculture subsidies rolls on.

For Francis Collins, being the NIH’s director is a daily experience of exhilaration and dismay.

In the last 40 years, he says, heart attacks and strokes have declined 60 percent and 70 percent, respectively. Cancer deaths are down 15 percent in 15 years. An AIDS diagnosis is no longer a death sentence.

Researchers are on the trail of a universal flu vaccine. Chemotherapy was invented here and is being replaced by treatments developed here.

Yet the pace of public health advances is, Collins says, being slowed by the sequester.

He entered federal service to oversee decoding the human genome, which he describes as “reading out the instruction book for human beings.”

We are, he says, at the dawn of the era of “precision medicine,” of treatments personalized for patients’ genetic makeups.

Other countries have “read our playbook,” seeing how biomedical research can reduce health costs, produce jobs and enhance competitiveness.

Meanwhile, America’s great universities award advanced degrees to young scientists from abroad, and then irrational immigration policy compels them to leave.

And now the sequester discourages and disperses scientific talent.

NIH scientists know that the enchantment of science is in the phrase “You never know.” You never know where things might lead.

Sixty years ago, James Watson and Francis Crick published a paper in the journal Nature describing the double-helix structure of DNA and noting almost laconically that it “suggests a possible copying mechanism for the genetic material.”

They could not have known that this would lead to Collins’ career, which has led him here to days of dismay about exhilarations postponed.

George Will is a columnist for The Washington Post. He can be contacted at:

georgewill@washpost.com