A promotional image for Man on Wire, the film about Philippe Petit’s quest to cross between the World Trade Center towers in 1974. Photograph: Shed Media Group Limited

When i was 21 years old, not too much older than you are now, I arrived in Boston from Dublin. I went out to Cape Cod and drove a taxicab in Hyannis. Later, I took off on a bicycle across the United States, and I entered that vast democracy of stories and storytelling.

People would talk to me, and I learned where I was, and I began to know who they were. And I realized that I was in a country of accumulating voices. All the voices I had met were meeting other voices in a sometimes graceful, sometime discordant way. A music.

I began realizing that I, too, was an amalgamation of so many voices. I grew up in Christian Brothers schools in Ireland. I got my voice from Brother Kelly, and from Mr. O’Connell, and from Mr. Hill, who rattled the school gates with his broken heart when he was forced into an early retirement. All my teachers voiced me in some way or other. I got a clip on the ear every now and then, too. I got my voice from that, as well.

Teachers gave to me the words of Gerard Manley Hopkins: “The world is charged with the grandeur of God. . . . There lives the dearest freshness deep down things.”

Hopkins was a man who, to me—reading him at the age of 15 and 16—was made even greater by his doubts. I found rapture in the moral, down-to-earth poetry of Patrick Kavanagh and Wilfred Owen (“foreheads of men have bled where no wounds were”). Much of what I was lucky to become came from the generosity of others—so many voices, my father, my mother, my brothers and sister. We all get our voices from others.

My faith allowed me to be open to the world. My family, my fellow students, and I, we were small radios looking for our antennae. And I feel today that I’m a small radio, looking for the music of what you are going to bring to the world.

You young people are perhaps the first 9/11 generation. The 10th anniversary of the twin towers’ destruction intersects with your first year of college. You and your generation will take what has happened in New York, in Baghdad, in London, in Madrid, in Kabul, and make of it, if not a peace, at least a pact. And if not stop it, at least push against it—if not to eradicate it, then at least to change it.

I walked around the labyrinth on the lawn of the Burns Library today, the path dedicated to the memory of Boston College alumni lost on 9/11. It’s one of the most beautiful symbols I’ve come across. It speaks to who we are and where we come from and how we learn from experience. The labyrinth constitutes the longest possible way to arrive at the center, and there’s no better way to talk about life. You can’t rush it. You must submit to it and learn from its intimate geography.

Much of what I wanted to do with my novel Let the Great World Spin was to find value and grace and meaning and, I hope, recovery, in the ongoing thrum of the world. While much of the book may seem to be about a tightrope walk across the space between the World Trade Center towers, the real core of the book is the intersection of the tiny tightropes that we all walk, sometimes a foot off the ground, sometimes a quarter of a mile in the sky. Eventually, the book is about the rescue of two small children in a housing complex in the Bronx, two tiny towers that are ultimately huge, the small, intimate towers of our lives.

I want to read a passage from the book, about the character Corrigan, an Irish monk who pledges his life to the intimate dramas of others. This is his brother talking:

Corrigan told me once that Christ was quite easy to understand. He went where He was supposed to go. He stayed where He was needed. He took little or nothing along, a pair of sandals, a bit of a shirt, a few odds and ends to stave off the loneliness. He never rejected the world. If He had rejected it, He would have been rejecting mystery. And if He rejected mystery, He would have been rejecting faith.

What Corrigan wanted was a fully believable God, one you could find in the grime of the everyday. The comfort he got from the hard, cold truth—the filth, the war, the poverty—was that life could be capable of small beauties. He wasn’t interested in the glorious tales of the afterlife or the notions of a honey-soaked heaven. To him that was a dressing room for hell. Rather, he consoled himself with the fact that, in the real world, when he looked closely into the darkness, he might find the presence of a light, damaged and bruised, but a little light all the same. He wanted, quite simply, for the world to be a better place, and he was in the habit of hoping for it. Out of that came some sort of triumph that went beyond theological proof, a cause for optimism against all the evidence.

“Someday the meek might actually want it,” he said.

There are times when we are called upon to engage with the darkness. This is relevant to all of you, and it’s relevant to your university education, which fits into a pattern of vision, justice, and charity. It’s very hard, as Yeats said, to “hold in a single thought reality and justice.” But every little corner is a world, and you are called upon to go into the smaller, darker, more anonymous corners. Your faith comes into play here. It’s only good when it’s truly being tested. I’ve sometimes had my faith tested. You go with it, and you gain from it, and you stay with the voices you trust. These things last. Hope lasts.

There’s a degraded discourse around the notion of optimism these days that says there is something soft about being an optimist—something wrong. It claims that optimism has no edge, as if it’s less than complete, less than the full deck of knowledge. The optimist is cartooned into the corner with an idiotic grin. I submit to you that none of that is true.

A good optimist never denies the reality of the dark. In fact, optimists are far more cynical than the best of cynics. They have to trump the cynic within. They have to examine the world. They have to go headfirst into the dark.

That is what learning is about. Cynics do not go forth. Cynics are trapped in their cynicism. It’s the end of the journey. They all fall down.

So much of good education is learning how to get to the other side of cynicism, how to cross that towering divide. This is not, I submit, sentimental. It’s full of sentiment, yes, but not sentimental. The best theologians, thinkers, philosophers, the best teachers, have always told us that we get to the light through the heart of the dark. You read, you engage. You become who you are by telling each other your stories. The bloodstream of the stories becomes the bloodstream of your life.

Still, our redemption doesn’t consist of words but of acts. The art of learning is the art of learning how to do, and the art of learning how to do is the art of learning how to change, not only yourself, but the things that are around you.

And let’s not fool ourselves. There’s a lot to change. You have heard the sound of those jetliners smashing into buildings, and listened to how it turned the word “justice” into “revenge.” You look at the robber barons who are back out on our streets, and at the destruction of our environment, the cheapening of our politics. There are more poor people in this country than at any time in the last 30 years.

I could become a good cynic and continue to rattle off what is wrong, but I’m a better cynic. I’m an optimist. I want to see the pressure that you will bring to bear on your government, the pressure that you’ll bring to bear on your Church, on yourself, on your University, on your teachers. You won’t do this by putting a smiley face on your Facebook page. Do I advocate rage? Yeah, a little bit of rage. But I advocate it as an act of hope.

I love the way that you lit those candles this evening, and everyone said to you, go forth and set the world aflame. But the fact of the matter is, it’s not going to be easy the whole time. Where you’re about to go is just about the most exciting place on the planet. I wish I were in your place. New challenges, new cultures, new ideas, new temptations—you’re about to go into doubt and joy and loss and learning and failure.

Failure? Did I say failure? So many times we are told how previous generations have failed us in some way. And they have failed us. The fact of the matter is I’ve failed you, your teachers have failed you, and the very best amongst you will fail, very well. And I’m happy about that, because failure is vivifying. Failure means you’ve tried something. Failure means that there’s something more to beat. The great Sam Beckett said, “No matter. Try again. Fail again. Fail better.” That’s the sort of failure that makes you and your folks proud.

If you can make the darkness visible, then you can make the light visible. So I call on you to practice resuscitation. Endure the rough weather. In fact, embrace it. Do not tread water. If you tread water, you might survive, but you won’t live. Swim in the waters that other people would drown in. Get ripped to pieces and learn to put yourself back together again.

Throw away the GPS. Read. Be like Job, and ask questions. Turn answers into more questions. Push the edge, become the edge. Expose your heart. Imagine yourself into the lives of those who do not have your advantages. Raise your voice on behalf of those who haven’t had a chance to raise their own. A long life isn’t good enough, but a good life is long enough.

Remind yourself every day how incredibly fortunate you are to be at this University. Bear your portion of the weight of the world. Embrace mystery. Call on difficulty for the sake of beauty. Have your mind work in tandem with your heart. And have a good time. Have a laugh. Fall in love. Fall too far. Turn the water into wine, and live your life out loud—put big, wide speakers in the windows of your head.

Be suspicious of that which gives you too much consolation. If I give you too much consolation, be suspicious of me. These are rough times.

The fact of the matter is that I’ve been waiting for you. We’ve been waiting for you. Your mothers, your fathers, your brothers and sisters, your grandparents, their grandparents, they’ve been waiting for you. Come along. Write a great poem. Find a great cure. We’ve been waiting for you to break open the arts, the sciences. We will, I hope, make great advances in your hands.

Novelist Colum McCann is the author most recently of Let the Great World Spin, for which he received the 2009 National Book Award. His essay is drawn from his keynote talk at First Year Academic Convocation on September 15 in Conte Forum, addressed to the University’s new class of freshmen.