Suppose that you had an opportunity to save somebody else’s life. Suppose that your own brother had been sentenced to death and you had the power to grant a reprieve. What would you do? Most of us like to think we’d do the right thing. If we could save another person’s life, especially a family member’s, we like to think that wouldn’t hesitate.

But the choice wasn’t so easy fifty years ago for Ronald Herrick. On December 23, 1954, he became the first person in history to donate one of his kidneys to save his brother Richard. Back in those days, removing a kidney was an untried procedure. Now it’s all done laproscopically, but then doctors actually had to break a rib to take the organ from the body. Many physicians were opposed to the idea of inflicting injury on a healthy patient even if it promised a second chance for someone else who was dying. The precept "do no harm" is central to the Hippocratic Oath. And in the popular press, Dr. Joseph Murray, the physician who performed the surgery at Boston’s Peter Bent Brigham Hospital and who eventually won a Nobel Prize for his work, was compared to a Dr. Frankenstein. The whole idea of organ transplantation struck many folk as unnatural and maybe even a bit ghoulish. And even Dr. Murray considered the operation something of a longshot. Transplantation appeared to hold out hope only in the rarest of circumstances–for the tiny number of cases like Ronald’s and Richard’s, who just happened to be identical twins. Anti-rejection drugs were still a thing of the future at that point, so it was by no means clear to Ronald, a healthy 23 year-old who’d just been discharged from the Army, or to his spitting image Richard, who’d recently been released from the Coast Guard but was then in a hospital dying of kidney disease, that their rather unusual case would help doctors learn how to benefit others down the road. Ronald, who is still alive at the age of 73 and who was interviewed recently on National Public Radio, says it was a hard decision to make, but when Richard tried to call off the operation the night before the surgery, he held firm. His brother went on to live another eight years, and together the two ushered in a medical revolution that would save another 400,000 lives over the next few decades. Was it worth it? In retrospect, there’s little doubt that Ronald made the right decision, medically and morally speaking. But at the time no one would have blamed him if he’d decided not to donate a kidney, and many would have praised him for his caution and good sense.

Suppose that you had the opportunity to save someone else’s life. Suppose that with very little sacrifice on your part you could prevent another person from experiencing a premature death. Would you be willing to give a kidney to save the life of your brother, or your sister, or your child? And how about saving the life of a total stranger? Most doctors consider the first entirely commendable and normal. When my mother gave me a kidney twenty years ago, no one blinked an eye, and certainly no one questioned her motives. Transplants by that time had become almost routine. The success rate for the recipient was very high and the risks for the donor practically nil. At the same time, there were tens of thousands of people on waiting lists, condemned to spend a good chunk of every week hooked up a dialysis machines. Many of them die waiting. Helping a family member get off dialysis has become commonplace now. And yet the notion of donating an organ to save the life of someone unrelated was and is still considered peculiar to say the least. A paper published in Seminars in Psychiatry in 1971 said that most doctors looked on the idea as "impulsive, suspect, and repugnant." And so it was not until five years ago that the first "non-directed" kidney donations took place. One of the first was Joyce Roush, herself a nurse with the Indiana Organ Procurement Program who understood the risks (or lack of them) quite well. She proposed herself to Dr. Lloyd Ratner, a leading transplant surgeon at Johns Hopkins, who was initially reluctant to discuss it. "Give me a call and we’ll consider," he told her, thinking he’d never hear from her again, only to find that she called and called, and was not to be put off. A deeply spiritual person, Joyce said she felt tapped on the shoulder by God. It was something practical and relatively easy she could do to make a big difference in the life of another person. So after a battery of psychological tests and bioethical consultations, she was finally allowed to donate one of her healthy kidneys to a thirteen-year-old boy. Joyce and Christopher both are alive and kicking today, and although a few people have followed in her footsteps, the number of "non-directed" donations remains relatively small. Just a few dozen are performed each year in the United States.

One of those was from Zell Kravinsky, whose story was written up in the New Yorker last summer. Kravinsky had already given away a fortune. After amassing a forty-five million dollar real estate empire–a million square feet of commercial property along with lofts, houses and condos–he began to be troubled by his own wealth and the disparity of so many who had little or nothing. He had to talk his wife into it, but in fairly short order, they were able to give away almost everything they owned. In 2002, they gave over $6 million to the Centers for Disease Control, and that same year they donated an 87,000 square foot apartment building to a school for the disabled in Philadelphia. The next year Zell and Emily donated properties worth around $30 million to support a School for Public Health at Ohio State University. Kravinsky had to compromise on his goal of total divestment. His wife insisted that he set up a small trust as security for her and their two children. But in the space of a couple of years Kravinsky took his own personal assets down to a quite modest level–a small home with a large mortgage, two old minivans and about $80,000 in stocks and cash. He’d gone from being a tycoon to a rather grungy existence in the lower middle class, meanwhile setting records for philanthropy. But for Zell Kravinsky, it wasn’t enough. He knew that if he wanted, he could give away much, much more.

Kravinsky wasn’t tapped on the shoulder by God so much as driven by a mathematical calculus. Raised in a Jewish family committed to socialism and left wing politics, he worked as a teacher in a Philadelphia ghetto before he discovered his inborn aptitude for making money. Interest rates, amortizations, and depreciation tables came naturally to him. Numbers and ratios were things he intuitively understood. So when he read an article in the Wall Street Journal explaining that a kidney donor had only a one-in-four-thousand chance of dying from giving up an organ, Kravinsky understood that this was like buying a U.S. government bond. The risk involved was almost zero. But unlike government bonds, the dividend or pay-out in this case was fabulous. Some lucky person would get a whole new life. The logic of it was irresistable.

It was the same irrefutable logic that had convinced Kravinsky to give away his money, to help as many people as possible. The right thing to do in any circumstance, according to the moral philosophy known as utilitarianism, is whatever will produce the greatest good for the greatest number. "Maximize happiness" ought to be our guiding principle–not just our own personal happiness, or the happiness of our close family and friends, but the felicity of people in general. And though many dispute this, utilitarians do have some powerful arguments on their side. Peter Singer, an Australian philosopher who now teaches at Princeton, is perhaps the most prominent spokesman for this view. In an essay titled "Famine, Affluence, and Morality," he set up a puzzle called the Shallow Pond and the Envelope. Imagine, he asks, a child who has fallen into a shallow pond and is in danger of drowning. Most of us would agree that we have an obligation to rescue the youngster, even if it means getting our clothes muddy or ruining our shoes. It would be callous to put a higher price on our footwear than on the life of an innocent child. But now imagine receiving an envelope from Oxfam or UNICEF, the kind of fundraising plea that arrives in our mailboxes regularly every month. Ignoring the envelope would be morally equivalent to ignoring the drowning child, Singer claims. In either case, we’d be permitting a harm that’s easily in our power to prevent.

To sharpen the dilemma, Singer proposes the hypothetical case of Bob, who is close to retirement. He has invested most of his savings in a very rare and valuable old car, a Bugatti, which he has not been able to insure. The Bugatti is his pride and joy. In addition to the pleasure he gets from driving and caring for his car, Bob knows that its rising market value means that he will always be able to sell it and live comfortably after retirement. One day when Bob is out for a drive, he parks the Bugatti near the end of a railway siding and goes for a walk up the track. As he does so, he sees that a runaway train, with no one aboard, is running down the line. Looking farther down the track, he sees the small figure of a child very likely to be killed by the runaway train. He can't stop the train and the child is too far away to warn of the danger, but he can throw a switch that will divert the train down the siding where his Bugatti is parked. Then nobody will be killed--but the train will destroy his beloved Bugatti. Thinking of his joy in owning the car and the financial security it represents, Bob hesitates. Should he protect the child or to guard his own retirement nest egg?

Suppose you had the opportunity to save someone’s life. What should you do? To Singer the answer is obvious. Whatever we possess above and beyond the bare necessities ought to be given to save those in desperate need. And so he has suggested that the solution to world poverty is simple. If all of us living in North America gave away any income in excess of $30,000 a year, the 40,000 children who die each day from hunger could all be fed. More than most, Mr. Singer actually practices what he preaches, donating twenty percent of his professor’s salary to charity every year. But Singer does spend more on his elderly mother, who has Alzheimer’s and needs specialized nursing care, than he does on total strangers. And generous though he is, he hasn’t cut his expenses down to the level he recommends to others. Nor has he volunteered up to this point to give away a kidney.

There is more to life than logic, after all. Zell Kravinsky has considered giving all his organs away. With a liver, two kidneys, and a perfectly good heart, he could save several lives in exchange for his one. The arithmetic makes perfect sense. But he knows the other children at school would tease his kids because their father was a freak, and he doesn’t want to be a bad Dad. He’d like to give away his clothes, too, but knows that if he went naked, investment bankers wouldn’t let him in the front door anymore. Kravinsky’s parents are furious with him, and his marriage is under enough strain as it is. Moral decisions can’t be analyzed mathematically anymore than relationships or families can.

Still, a young black woman named Donnell Reid who was trapped on a dialysis machine for eight years before Kravinsky gave her back her health and freedom is convinced her benefactor is a hero. But that’s not how Zell Kravinsky sees himself. He thinks of himself as just an ordinary guy trying hard to do the right thing. No one should have two houses while there are people who are homeless, he argues. Why should he have two kidneys while there are thousands of people who are dying to get just one? He’s been criticized in the press by journalists who have questioned his motives, accused him of grandstanding, and called him a lunatic. But Ronald Herrick, the very first kidney donor, was criticized by the papers, too, along with the surgeon who did the operation. So is Zell Kravinsky a first class crank, or simply ahead of his time? You tell me. How good do we have to be?