As I write this, Barney Clark is surviving. The heart inside his chest, a contraption of polyurethane that replaced his own devastated muscle, is still working.

But the bulletins from the hospital that told us how he spent his days--sleeping, listening to Handel's "Messiah," dangling his feet, breathing -- now tell us of seizures. On the seventh day of this vigil, his medical status was labeled critical.

Watching the life of this "first" from my seat in the national gallery, I think about the moment Monday when a reporter asked the nurse whether Dr. Clark thought of himself as a medical pioneer. The nurse said no. What her patient thought about was the daily business of his recovery. "He talks about, 'Am I going to sit up today?'"

I suppose this wasn't his time to be introspective. Maybe it's not ours, either. We have before us a dying man who was saved, at least for awhile. We have before us another, yet another, breakthrough for medical technology. Maybe it's the time for news magazine covers, toasts to life and huzzahs.

Yet I think we do need a moment for reflection. Once again we are surprised, caught unaware by some medical advance on our lives. A technology known only to the readers of medical journals jumps out at us from headlines. It happened before when the first kidney was transplanted, the first test-tube baby was born, and now as the first artificial heart is implanted.

Surprise seems to be a fallout of our own successful marketplace medicine. Our doctors are trained to respond to the orders of need, our scientists to manufacture cures. We receive handsome gifts of progress for our health-shelf.

Yet often the gifts come with strings attached. They come from decisions that should have been made in public, not just announced to the public. They come without warning tags about hidden costs.

Daniel Callahan, director of the Hastings Center Institute of Society, Ethics and Life Sciences, where they deal in trade-offs and hard choices, has studied each catalog of technologies and possibilities with a careful eye. "The fundamental philosophical issue," he says "is just how far do we want to go in extending and improving life."

There are costs even in cures. "The current crisis over Social Security," Callahan points out, "is one more consequence of the triumph of medical progress."

We have to concern ourselves with the allocation of resources. Not just money, but human as well. The early trade-offs of technology were simple. Vaccinations and antibiotics cost little and helped millions. Today, expensive advances help fewer people and add fewer years to the human life span.

We haven't devised a way to think about such high-ticket items as artificial hearts. How do we determine the relative costs and value of research that went into this device, rather than into, say, money for child nutrition or basic prenatal care? How do we determine the relative cost and value of dealing with heart disease versus lung disease?

If it's hard to decide what sicknesses deserve priority, it's even harder to decide what people deserve priority. Today we pay for any American who needs kidney dialysis to stay alive: $1.6 billion a year for 70,000 Americans. This way, we avoid choosing among kidney victims. But it's unlikely that any other disease will be voted a blank check.

On what basis will we distribute scarce high-tech medicine? Will a couple like Roger and Judith Carr get a test-tube baby only if they can afford the treatment? Will a girl like Jamie Fiske get a liver only if her parents are savvy enough to lobby medical meetings and talk shows? Will a man like Barney Clark get an artificial heart only if he has "a stable home situation" with a "reliable spouse" as well as a "stable psychological mechanism"?

"The traditional ethic of medicine," says Callahan, "is that you do everything possible for the patient. Doctors are not in the policy business of allocating medical research nationwide. We want doctors who are worried about us, doctors who are our advocates."

Dr. Clark was not introspective in his sick bed. None of us is. We don't chew over moral dilemmas when we're sick. We want to know, "Am I going to sit up today?" We want a cure, and damn the costs.

It would be unreasonable, unhealthy, to turn off medical technology. Yet we need a public dialogue, a sense that we are participating in the ethical decisions, the moral choices, the social trade-offs. We don't need any more surprises.