I don’t know who President George W. Bush will miss more, Tom DeLay or Leon Kass, who stepped down from their official jobs in Washington within days of each other last month.

But I do have a belief about which of the two Bush allies made a more lasting and edifying contribution to a proper understanding of U.S. politics. And it’s not DeLay.

Maybe this judgment isn’t fair, and by most practical measures it’s certainly perverse. DeLay, after all, is a thoroughly political creature, the kind that official Washington is used to, and Leon Kass is not.

Kass is an intellectual, and his sojourn through the federal bureaucracy as chairman of the President’s Council on Bioethics has been political in the broadest and best sense of the word. It was less a matter of allocating the spoils of power than an experiment in how a democracy might treat the intersection of government and the big human questions of living and procreating, aging and dying.

In this sense of politics – if I’d finished graduate school I might dare to call it “Aristotelian” – Kass’s four-year tenure in Washington was a rare and noble exercise. He deserves a tip of the hat as he steps aside.

Kass’s last public act as chairman was true to form. Bush created the bioethics council in 2001 to “undertake fundamental inquiry into the human and moral significance of developments in biomedical and behavioral science and technology.”

In keeping with this mandate, the council has issued seven reports as well as millions of words of background research and hearing transcripts. Last month came “Taking Care: Ethical Caregiving in Our Aging Society.” Like its predecessors, it was beautifully written, filled with solid information and vigorous argument and capped with conclusions uncontaminated by conventional wisdom.

The report examined the social difficulties, daily becoming harder to ignore, raised by a “mass geriatric society.” People over 85 constitute the most rapidly growing segment of the population. This splendid news comes with a shadow: Many of them – many of us – are or will be in the throes of advanced dementia, requiring caregiving resources that Western societies, for all their vast wealth, seem ill-prepared to provide.

In Washington, this looming crisis is thought of purely in fiscal terms: How will Medicare pay the bills? Kass and the council worry that the number-crunching approach, left to itself, threatens to turn human beings into liabilities and assets on a balance sheet.

Instead, they begin their discussion with more fundamental questions, such as what constitutes humane care of the senescent, who should provide it and how the task can ennoble both the giver and receiver of care.

“We were striving to emphasize the largest ethical dimensions of the question,” Kass said in an interview, “and not simply the economic or institutional ones.”

The emphasis on the long view was strange for Washington but typical for the council and, as it has before, it yielded surprising conclusions.

For example, the council considered the new enthusiasm for living wills. In the wake of the horrifying Terri Schiavo case, these and other advanced directives were glibly offered as a panacea by every talk-show chin-puller and newsmagazine deep-thinker.

The council arrived at a different view.

Living wills, the report concluded, “address, at most, but a small fraction of the decisions caregivers must make for incapacitated persons. There are too many situations in which following orders is not the best way to give care, and giving care always requires more in terms of resources, character, support and judgment than any legal instrument can possibly provide.”

By trying to move beyond the purely political and pragmatic, the council has sometimes left itself open to criticism or, what’s worse, shrugs of bewilderment.

“Taking Care” closes, for instance, with a call for a presidential commission on aging, dementia and long-term care – leaving us with the specter of one presidential commission issuing a report calling for another presidential commission, which will then doubtless issue reports of its own, perhaps including a call for still another commission. Only rabbits should breed with such wild abandon.

This is a rare lapse and an understandable one. Over the past four years, Kass says, he has tried “to find a way, in an operational sense, to be really helpful to the people who actually make the decisions in government. But the difficulties of combining the world of thought and the world of action make for an old, old story.”

He freely admits he’s not sure he succeeded in resolving the difficulty.

Neither am I. But that’s setting the threshold of success rather high. What Kass has done as chairman is to provide policy makers with an unprecedented repository of careful analysis and argument that they can consult with profit for years to come.

The issues the council has considered – cloning, stem cell research and the new uses of biotechnology in therapy and human reproduction – are political in both the practical and philosophical senses of the word. They won’t go away – and neither, we should hope, will the contributions made by Kass and his council.

Mr. Ferguson is a columnist for Bloomberg News.