The very least you can do in your life is to figure out what you hope for. The most you can do is live inside that hope, running down its hallways, touching the walls on both sides.

Let me begin that way: with an invocation of your own best hopes, thrown like a handful of rice over this celebration. Congratulations, graduates. Congratulations, parents, on the best Mother's Day gift ever. Better than all those burnt-toast breakfasts: these, your children grown tall and competent, educated to within an inch of their lives.

What can I say to people who know almost everything? There was a time when I surely knew, because I'd just graduated from college myself, after writing down the sum of all human knowledge on exams and research papers. But that great pedagogical swilling-out must have depleted my reserves, because decades have passed and now I can't believe how much I don't know. Looking back, I can discern a kind of gaseous exchange in which I exuded cleverness and gradually absorbed better judgment. Wisdom is like frequent-flyer miles and scar tissue; if it does accumulate, that happens by accident while you're trying to do something else. And wisdom is what people will start wanting from you, after your last exam. I know it's true for writers - -- when people love a book, whatever they say about it, what they really mean is: it was wise. It helped explain their pickle. My favorites are the canny old codgers: Neruda, Garcia Marquez, Doris Lessing. Honestly, it is harrowing for me to try to teach 20-year-old students, who earnestly want to improve their writing. The best I can think to tell them is: Quit smoking, and observe posted speed limits. This will improve your odds of getting old enough to be wise.

[...]

The world shifts under our feet. The rules change. Not the Bill of Rights, or the rules of tenting, but the big unspoken truths of a generation. Exhaled by culture, taken in like oxygen, we hold these truths to be self-evident: You get what you pay for. Success is everything. Work is what you do for money, and that's what counts. How could it be otherwise? And the converse of that last rule, of course, is that if you're not paid to do a thing, it can't be important. If a child writes a poem and proudly reads it, adults may wink and ask, "Think there's a lot of money in that?" You may also hear this when you declare a major in English. Being a good neighbor, raising children: the road to success is not paved with the likes of these. Some workplaces actually quantify your likelihood of being distracted by family or volunteerism. It's called your coefficient of Drag. The ideal number is zero. This is the Rule of Perfect Efficiency.

Now, the rule of "Success" has traditionally meant having boatloads of money. But we are not really supposed to put it in a boat. A house would the customary thing. Ideally it should be large, with a lot of bathrooms and so forth, but no more than four people. If two friends come over during approved visiting hours, the two children have to leave. The bathroom-to-resident ratio should at all times remain greater than one. I'm not making this up, I'm just observing, it's more or less my profession. As Yogi Berra told us, you can observe a lot just by watching. I see our dream-houses standing alone, the idealized life taking place in a kind of bubble. So you need another bubble, with rubber tires, to convey yourself to places you must visit, such as an office. If you're successful, it will be a large, empty-ish office you don't have to share. If you need anything, you can get it delivered. Play your cards right and you may never have to come face to face with another person. This is the Rule of Escalating Isolation.

And so we find ourselves in the chapter of history I would entitle: Isolation and Efficiency, and How They Came Around to Bite Us in the Backside. Because it's looking that way. We're a world at war, ravaged by disagreements, a bizarrely globalized people in which the extravagant excesses of one culture wash up as famine or flood on the shores of another. Even the architecture of our planet is collapsing under the weight of our efficient productivity. Our climate, our oceans, migratory paths, things we believed were independent of human affairs. Twenty years ago, climate scientists first told Congress that unlimited carbon emissions were building toward a disastrous instability. Congress said, we need to think about that. About ten years later, nations of the world wrote the Kyoto Protocol, a set of legally binding controls on our carbon emissions. The US said, we still need to think about it. Now we can watch as glaciers disappear, the lights of biodiversity go out, the oceans reverse their ancient orders. A few degrees looked so small on the thermometer. We are so good at measuring things and declaring them under control. How could our weather turn murderous, pummel our coasts and push new diseases like denge fever onto our doorsteps? It's an emergency on a scale we've never known. We've responded by following the rules we know: Efficiency, Isolation. We can't slow down our productivity and consumption, that's unthinkable. Can't we just go home and put a really big lock on the door?

Not this time. Our paradigm has met its match. The world will save itself, don't get me wrong. The term "fossil fuels" is not a metaphor or a simile. In the geological sense, it's over. The internal combustion engine is so 20th Century. Now we can either shift away from a carbon-based economy, or find another place to live. Imagine it: we raised you on a lie. Everything you plug in, turn on or drive, the out-of-season foods you eat, the music in your ears. We gave you this world and promised you could keep it running on: a fossil substance. Dinosaur slime, and it's running out. The geologists only disagree on how much is left, and the climate scientists are now saying they're sorry but that's not even the point. We won't get time to use it all. To stabilize the floods and firestorms, we'll have to reduce our carbon emissions by 80 percent, within a decade.

[...]

How can we get from here to there, without burning up our ship? That will be central question of your adult life: to escape the wild rumpus of carbon-fuel dependency, in the nick of time. You'll make rules that were previously unthinkable, imposing limits on what we can use and possess. You will radically reconsider the power relationship between humans and our habitat. In the words of my esteemed colleague and friend, Wendell Berry, the new Emancipation Proclamation will not be for a specific race or species, but for life itself. Imagine it. Nations have already joined together to rein in global consumption. Faith communities have found a new point of agreement with student activists, organizing around the conviction that caring for our planet is a moral obligation. Before the last UN Climate Conference in Bali, thousands of U.S. citizens contacted the State Department to press for binding limits on carbon emissions. We're the five percent of humans who have made 50 percent of all the greenhouse gases up there. But our government is reluctant to address it, for one reason: it might hurt our economy.

For a lot of history, many nations said exactly the same thing about abolishing slavery. We can't grant humanity to all people, it would hurt our cotton plantations, our sugar crop, our balance of trade. Until the daughters and sons of a new wisdom declared: We don't care. You have to find another way. Enough of this shame.

[...]

A lot of people, in fact, are rethinking the money answer. Looking behind the cash-price of everything, to see what it cost us elsewhere: to mine and manufacture, to transport, to burn, to bury. What did it harm on its way here? Could I get it closer to home? Previous generations rarely asked about the hidden costs. We put them on layaway. You don't get to do that. The bill has come due. Some European countries already are calculating the "climate cost" on consumer goods and adding it to the price. The future is here. We're examining the moralities of possession, inventing renewable technologies, recovering sustainable food systems. We're even warming up to the idea that the wealthy nations will have to help the poorer ones, for the sake of a reconstructed world. We've done it before. That was the Marshall Plan. Generosity is not out of the question. It will grind some gears in the machine of Efficiency. But we can retool.

We can also rethink the big, lonely house as a metaphor for success. You are in a perfect position to do that. You've probably spent very little of your recent life in a free-standing unit with a bathroom-to-resident ratio of greater than one. (Maybe more like 1:200.) You've been living so close to your friends, you didn't have to ask about their problems, you had to step over them to get into the room. As you moved from dormitory to apartment to whatever (and by whatever I think I mean Central Campus) you've had such a full life, surrounded by people, in all kinds of social and physical structures, none of which belonged entirely to you. You're told that's all about to change. That growing up means leaving the herd, starting up the long escalator to isolation.

Not necessarily. As you leave here, remember what you loved most in this place. Not Orgo 2, I'm guessing, or the crazed squirrels or even the bulk cereal in the Freshman Marketplace. I mean the way you lived, in close and continuous contact. This is an ancient human social construct that once was common in this land. We called it a community. We lived among our villagers, depending on them for what we needed. If we had a problem, we did not discuss it over the phone with someone in Bubaneshwar. We went to a neighbor. We acquired food from farmers. We listened to music in groups, in churches or on front porches. We danced. We participated. Even when there was no money in it. Community is our native state. You play hardest for a hometown crowd. You become your best self. You know joy. This is not a guess, there is evidence. The scholars who study social well-being can put it on charts and graphs. In the last 30 years our material wealth has increased in this country, but our self-described happiness has steadily declined. Elsewhere, the people who consider themselves very happy are not in the very poorest nations, as you might guess, nor in the very richest. The winners are Mexico, Ireland, Puerto Rico, the kinds of places we identify with extended family, noisy villages, a lot of dancing. The happiest people are the ones with the most community.

You can take that to the bank. I'm not sure what they'll do with it down there, but you could try. You could walk out of here with an unconventionally communal sense of how your life may be. This could be your key to a new order: you don't need so much stuff to fill your life, when you have people in it. You don't need jet fuel to get food from a farmer's market. You could invent a new kind of Success that includes children's poetry, butterfly migrations, butterfly kisses, the Grand Canyon, eternity. If somebody says "Your money or your life," you could say: Life. And mean it. You'll see things collapse in your time, the big houses, the empires of glass. The new green things that sprout up through the wreck -- - those will be yours.

The arc of history is longer than human vision. It bends. We abolished slavery, we granted universal suffrage. We have done hard things before. And every time it took a terrible fight between people who could not imagine changing the rules, and those who said, "We already did. We have made the world new." The hardest part will be to convince yourself of the possibilities, and hang on. If you run out of hope at the end of the day, to rise in the morning and put it on again with your shoes. Hope is the only reason you won't give in, burn what's left of the ship and go down with it. The ship of your natural life and your children's only shot. You have to love that so earnestly -- - you, who were born into the Age of Irony. Imagine getting caught with your Optimism hanging out. It feels so risky. Like showing up at the bus stop as the village idiot. You may be asked to stand behind the barn. You may feel you're not up to the task.

But think of this: what if someone had dared you, three years ago, to show up to some public event wearing a big, flappy dress with sleeves down to your knees. And on your head, oh, let's say, a beanie with a square board on top. And a tassel! Look at you. You are beautiful. The magic is community. The time has come for the square beanie, and you are rocked in the bosom of the people who get what you're going for. You can be as earnest and ridiculous as you need to be, if you don't attempt it in isolation. The ridiculously earnest are known to travel in groups. And they are known to change the world. Look at you. That could be you.

I'll close with a poem:

Hope; An Owner's Manual

Look, you might as well know, this thing is going to take endless repair: rubber bands, crazy glue, tapioca, the square of the hypotenuse. Nineteenth century novels. Heartstrings, sunrise: all of these are useful. Also, feathers.

To keep it humming, sometimes you have to stand on an incline, where everything looks possible; on the line you drew yourself. Or in the grocery line, making faces at a toddler secretly, over his mother's shoulder.

You might have to pop the clutch and run past all the evidence. Past everyone who is laughing or praying for you. Definitely you don't want to go directly to jail, but still, here you go, passing time, passing strange. Don't pass this up.

In the worst of times, you will have to pass it off. Park it and fly by the seat of your pants. With nothing in the bank, you'll still want to take the express. Tiptoe past the dogs of the apocalypse that are sleeping in the shade of your future. Pay at the window. Pass your hope like a bad check. You might still have just enough time. To make a deposit.

Congratulations, graduates.

Excerpted from "How to be Hopeful," the title of the speech Barbara Kingsolver delivered at Duke's 2008 commencement ceremony May 11 at Wallace Wade Stadium. You can read the full address here.