Congratulations graduates. What a great day for you! And congratulations to all of the parents and grandparents, brothers and sisters, aunts and uncles and cousins, children and other family members, and friends and teachers who came to this wonderful celebration. All of you helped make this day happen through your support of these graduates. This day marks a huge accomplishment by all of you! Terrific!

So, what's next, graduates? What is post-college life—that is, life—all about?

I have come to think about life as an ongoing series of puzzles and problems that present themselves. All through college, we are asked to solve problems of various kinds. But what's different on the day after graduation is that there is no professor telling you "you got the right answer."

Some of life's puzzles will be fun and even simple, like jigsaws or ken-kens and crosswords. But most are much more complicated than that.

I chose this problem-solving image because of my own experience. When I graduated from college, I went directly on to graduate school, and I was actually surprised at first to realize that my thesis advisor had no idea how my immunology experiments would turn out. She was not like my college biology professors, who knew the answers to the experiments that we did in our labs.

So, it was then that I thought: Gosh: the questions and puzzles and problems in the lab are now all new, and it's up to me to figure out how to solve them. And, of course, the puzzles and issues that I faced outside the lab in my personal life were all new too.

As soon as I realized this, I was profoundly grateful—and have continued to be grateful—that a key component of my college experience—and I'm sure yours too—was learning how to learn. Facts and details and specifics are important, but what really has always served me the most was understanding creativity, the process of learning, ways to approach new situations, analyze puzzles, and solve problems.

I started out as a scientist. But, with time, I switched to being a science writer, because I wanted to describe scientific discoveries to scientists and to the public rather than make the discoveries myself.

Later, I became a bioethicist and a professor, because I wanted to teach and write about what scientific discoveries might mean in our lives, rather than just say what they were.

Bioethics did not even exist when I was in college, so there was absolutely no way that I could have studied specifically to be a bioethicist or predicted that I would be one.

My interests evolved with the times and the changes in the world, and I moved from one kind of work, one kind of problem solving, to another.

It wasn't that I didn't like what I was doing, but each time I made a switch it was because the next thing looked to me to be both more interesting and more important for me to do.

Let me explain what bioethics is and how it came about in the decade after I graduated from college. In those years, we were seeing dramatic advances in every kind of technology. The new technologies allowed us to do things that previously had been impossible.

In medicine, one of the first technologies that dramatically changed the landscape in the hospital was the respirator. That's the device that can keep injured and sick people breathing when their own lungs are not working.

That was the good news.

But, pretty soon, we began to see the down side of the respirator. Some people who got connected to respirators could not ever get off them. These people were alive but not really living. Many endured lengthy and painful struggles. I'm sure some of you know people who are or were trapped by respirators and how impossible the situation becomes, both for the person and for the person's family and friends.

The term "halfway technology" was coined: the respirator got people only halfway back to where they needed to be in order to go on living a substantive life. They were stuck, and this was not what any of us would call "living."

All of a sudden, people realized that we had to think about new technologies differently. We needed to slow down and say: We can do this, but SHOULD we?

Bioethics asks the "should" questions: should we do this, should we use this technology, simply because it exists?

Every time a new technology was developed in medicine or in any other field, more and more of the "should" ethical questions came up.

And while many new medical technologies are truly miraculous, some will always leave people in the half-way zone, sometimes doing more harm than good.

What we began to understand was that technologies are not inherently good or bad; it's how we use them that determines their value.

Grappling with these issues is what bioethics is all about.

The other day on the radio, I heard someone say that a knife can be used to butter your morning toast or stab someone. That's what I mean by saying that it is HOW we use the technology that determines whether it is good or bad, rather than the technology itself.

We bioethicists spend our time considering the implications of what we can now do with new technologies. We ask whether the benefits will outweigh the risks. We ask if the use of the technology is fair. We look for ways to draw public attention to the concerns and issues.

The puzzles and problems are complex and nuanced; the solutions are not always as good as we'd like. But, we can't just look away, because all of our lives are affected by not just the successful technologies but also the halfway and harmful ones.

Last week, I read two articles that will show you how people have chosen to use a technology, specifically, the internet, for good and for mischief.

The first article was in the New Yorker and it really disturbed me. It was a profile of a young guy who is a virtuoso computer hacker. Why did he get into hacking? He said he was bored. How sad, I thought, that instead of using his obviously prodigious computer skills and talents to do good in the world he had chosen to spend his time wreaking havoc. (What a jerk!)

The second article, which was in the New York Times, described how top executives at Facebook had decided to add a feature to Facebook that could help increase organ donations. Now here is an example of the exact opposite: someone sees a way to use the internet and its social media technology features to do something that could benefit—in fact, save the lives of—tens of thousands of people every year.

The Facebook CEO got the idea to do this because a college friend of hers, a transplant doctor, had written about the struggles he was facing not finding enough organs for his needy patients. She realized that Facebook would have a straightforward way to help with the mismatch of supply, which is currently small, and demand, which is currently huge. Facebook would add a feature that let people indicate on their pages whether they wanted to be organ donors or not.

The issues associated with organ shortages and organ transplantation are ones that I have thought about for many years as a bioethicist, discussed with my students, and written about.

Because the supply of available organs does not meet the demand, many ethical issues arise:

Who should get the scarce organs that are available: Should it be the sickest person? Or should it be the one most likely to do well? Or should it be the youngest one? Or should it be someone considered important in the community? Or should it be someone famous?

Another question: If a donor has three organs that can be transplanted, is it better to give them to someone who needs all three or give them to three people, each of whom needs just one organ?

Does the recipient of an organ owe anything to the family of the donor? If so, what?

What's fair and just in making these choices? What choices produce the most good?

Should we be setting up a marketplace in which organs can be bought and sold? (Currently, this is not allowed in our country.)

These are just a few of the complicated, troubling, and very interesting ethical quandaries that are associated with organ transplantation, and I'm sure you can see how each question gets even more complicated by political, social, legal, economic, religious, and cultural variables mixed into the underlying medical considerations.

In bioethics, we call such puzzles dilemmas. They are very complex, there often is no one right answer, there may be several equally good and equally bad solutions, but we still must grapple with them.

And, for every family and every person who faces one of these medical dilemmas, you can imagine how the best or the right solution will be different depending on the specific circumstances.

Even more concerning is the question: Who should be making all of these decisions? Are there specific people in our society who you would like to make them? If so, who? Or will you, as a thinking citizen, get into the conversation?

Bioethics is an expanding, actually a burgeoning, field, because complex ethical issues associated with healthcare are growing, not going away. While being troubling, these are also absolutely fascinating puzzles to work on.

Many bioethicists, including me, frame the bioethical problems in individual true stories, called case studies or case histories. We break down each case this way: What are the issues? What are the options? What people are involved? Who has a stake in the outcome? Who are the decision makers? How do the decision makers come to consensus? How can those who are not happy with the decision be made comfortable with the decision—the solution—and feel that they too were accommodated?

My first book, Baby at Risk, includes case histories of babies who were born either very sick or much too early. Some of these babies did really well, thanks to new technologies in the neonatal intensive care units of hospitals. But, for some, the rescue technologies proved to be halfway technologies, and the babies have gone on to live extremely difficult lives, often filled with intense suffering for the baby and huge, life-long struggles for the parents and siblings and others involved in the babies' care.

I had not intended to write that book, but began my research into babies because I was curious how decisions were made in the neonatal intensive care unit. I spent months interviewing the head of the unit at Georgetown University Medical Center and later interviewing other medical and nursing staff members and family members and others. But as I learned more and more, I saw that I could play an important role in the worlds of these babies and their families and the doctors and nurses who cared for them by raising awareness to issues in an honest way.

The media were always hyping stories about tiny babies "born the size of a coke can" or drawing giddy attention to the births of quintuplets and even the crazy "octomom." But they rarely went back to revisit the families and report on how these babies were doing later in their lives. Yet, more often than not, these babies were not doing well.

I wanted to correct this misperception and explain to the public that not every teeny tiny baby could go on to lead a healthy life. I wanted young women and men who were becoming parents to be aware that they had important rights in the decision-making processes that concerned their own babies. And I wanted hospital staff to realize that there were consequences to some of the heroic but sometimes foolish experimental things they were doing. I also wanted the public to become aware that they could be more proactive in helping families in their community and more compassionate toward them as they navigated the world of sick babies.

No one dreams of having a sick baby, but it happens, and awareness on all sides might help to make some of the outcomes better.

When that book was published, I did talks to nursing and medical groups, ethics committees in hospitals and at universities, community groups, at bookstores, and even for a business school. (Babies are big business.)

And what amazed and pleased me was that everyone understood that we, as a society, needed to discuss these issues and not just look away from these families.

We needed to start talking about the "should" questions in the context of sick babies, as painful as they are, and find ways to help the babies and their families more.

As I said, it was gratifying for me to have found this opportunity to start these discussions in a wide range of people, naming the problems and puzzles, enlisting people in the search for better solutions, and bringing the affected families out of the isolation that they felt.

So, what problems are you going to attack?

Each of you graduates will now begin to find your own distinctive way of choosing the puzzles that you want to address. You will bring to the task your unique brain, which includes everything you've learned so far about problem solving, what you've seen, what you've experienced, the skills you've developed for critical thinking.

I find it a miracle that all of our different brains—each with its sloshing chemicals and firing electrical signals—can actually communicate with other brains, but we know this happens.

Many of you will get into a particular groove professionally right after you leave here, and you'll stay there. And that's fine. Lots of people do that. They have an idea of what they want to do, they find the right job (and, by the way, all you need is one), and doing the work they always had in mind makes them happy.

Others of you will move around more, as I have done.

I know many of you were pinned as nurses last night. Many of you will be in health care in this or other capacities—in psychology, radiology. Many of you will be working in the criminal justice system. Many will be teachers and writers. Many will be doing policy work or service work or research.

I hope some of you will be interested in bioethics. And let me just add that all hospitals have ethics committees that grapple with medical dilemmas, and all of these committees include, not just medical and nursing staff members and lawyers and religious leaders, but also community representatives. The latter are people with no special expertise in medical ethics—just people who want to talk about and think seriously and critically about the "should" issues. So, graduates (and family members too), go for it ... get involved at your local hospital, if this interests you.

You will find as you enter the work world that there is no single path that you must take to get to a particular career. When I was a writer at Science magazine many years ago, half of the writers were former scientists who had decided to leave the lab and go into writing; the other half were writers first who had a special interest in the topics of science. And both trajectories had led people to the exact same place.

So, the task ahead of you is really to figure out what engages you the most and head in that direction. Keep your eyes open, keep your brain active, and find out what you love to do.

Spend your time doing work that is worth doing, that will make the world a lot better, or even just a little bit better, that will make it more fair and more just. And, if what you are doing turns out not to be right for you, move on. So much needs to be done, to be fixed, so just look around you and try again. I don't think I need to list all of the injustices that we know about in the world today that must be stopped.

A decade ago, at the college graduation of my older daughter, the speaker, who is the head of an international relief organization, said, "We cannot retreat to the convenience of being overwhelmed." What she meant was that the daunting problems in the world sometimes make us feel hopeless and powerless. And sometimes we question the value of our small, individual contributions. But, each of us can make a difference in the world, and we must.

I have been strongly influenced by the saying, "If you are not part of the solution you are part of the problem." If you just sit there and watch bad things happen or watch injustices go on, then you are part of the problem. Sometimes it's hard to step up, to face down a bully, or someone who is causing harm, or someone acting with prejudice, or someone who is lying, but you must. It's hard to blow the whistle on unjust or corrupt practices, but you must do it.

I believe that all people, that is, all sane people, want peace. But I know that we will only achieve peace when we have justice in the world.

Today, the injustices, the inequities, between people are too, too great. Not just between people in the developed world and the developing world, but also here in what is called the developed world.

Work for justice: that's the step we can all make toward peace.

It's never too late to right wrongs, to expose problems. Earlier this year, when I was working for President Obama's bioethics commission, the project was focused on addressing hideous experiments that researchers from the U.S. Public Health Service did in Guatemala in the late 1940s.

Why should we care about that now, sixty years after it happened? Because if we do not point out corruption, do not raise awareness to injustices, do not take responsibility and apologize for harms done to others, and do not make all of this public, then surely we will see more and more unethical practices of this sort occurring in the future.

We must always raise awareness to violations of human rights, violations of civil rights, and crimes committed against humanity.

Okay. Go register to vote. Have a say in who is making decisions that will affect your life and the lives of everyone you love. Or become a legislator yourself.

Find your niche. Go out there and do good work. Make sure that your life is engaging for you and meaningful to yourself and to others.

Find work to which you can make a fire-in-the-belly commitment. Such work will make you deeply happy and proud.

Stop tweeting and texting and updating your facebook page (unless you want to add in your organ donation status!).

Get your life going. And have a great one!

If I can help you, let me know.

And, sometime in the coming years, when you have a minute, come to my website www.RuthLevyGuyer.net and tell me how and what you're doing!

Best wishes to each of you! And thank you.