In February 2005, wrapped up against the cold in London's Trafalgar Square and wearing a magnificent fur hat, Nelson Mandela -- who had supposedly retired from public life -- gave one of the greatest speeches of this century or any other, a challenge that over the next month, as a new development agenda is adopted by the nations of the world, should motivate and inspire leaders and the millions who hold them to account.
"Sometimes," Mandela said, "it falls upon a generation to be great. You can be that great generation."
The way to do so? By making poverty history, Mandela said, by recognizing that "Millions of people remain trapped in the prison of poverty. It is time to set them free."
In all the words that will be said in the next few weeks as we prepare for the U.N. to adopt a set of Global Goals for Sustainable Development, during all the demonstrations and concerts, the world will have failed if it does not take Mandela's charge to heart.
The 17 Global Goals amount to a set of organizing principles for a world hungry to act with courage and vision. They are a plan -- a strategy to rally around and a blueprint with which to build a world where kids don't go to bed hungry, where girls get the same opportunity to thrive as boys, and where people don't die of preventable diseases.
All of these issues -- of health, and inequality, and gender opportunity, and many more -- are ones on which those who dream of a better world should campaign. But the Global Goals start with one overarching imperative, and are right to do so: This year, says the first goal, we will commit to ending poverty in all its forms everywhere.
The gobsmacking audacity of such an ambition prompts two questions. First: can it be done? And second: why would one want to commit oneself to such a thing?
The good news is, yes, it can be done. We know what works. The last quarter of a century -- a period I've dubbed The Age of Miracles -- has seen the greatest reduction in absolute poverty that humanity has ever known. Much of that, everyone understands, has been because of the extraordinary development of the Asian economies and societies, and anyone who has lived in east Asia -- as I have -- knows the sense of wonder that comes from the almost palpable improvement of families' lives as economies grow.
But it isn't just Asia. As we increasingly understand the key investments needed to end poverty and encourage economic growth -- in health, in agriculture and nutrition, in education, in improving the life chances of women and girls, in vital infrastructure -- so one can see poverty in retreat from favelas in Brazil to villages in Burundi.
Getting to zero, to be sure, will be hard. The last billion of those living in extreme poverty will disproportionately live in places where conflict, violence, and everyday insecurity blight progress. War zones are poor zones. To answer the old song's question: There's nothing funny about peace, love and understanding. They make for a better life. But here, too, there are grounds for optimism. Despite the horrors and the headlines with which we are all familiar, war and violence are in retreat as a defining characteristic of our world.
So if we can eliminate poverty -- and we can -- why should we bind ourselves to do so?
The conventional reasons are familiar. Because a more prosperous world is a safer world, one where young men and women don't have to go off and fight to protect their families, where the turmoil of tough regions doesn't spill over into the lives of those of us lucky enough to live in more placid climes. Because ending poverty is a self-perpetuating cycle: it creates more opportunity not just where it has happened, but everywhere else, as trade and investment grow.
But Mandela, as so often, got to the real answer of why we should seek to eliminate poverty.
We should do so because its continued existence is a stain on our shared sense of what it means to be human. Looking the other way while millions live in avoidable poverty means that we are acquiescing in something that diminishes ourselves; it means accepting that nothing other than an accident of geography -- the place where your mother gave birth -- determines how (and whether) you live.
Mandela knew better. "Like slavery and apartheid," said Mandela in Trafalgar Square, "poverty is not natural. It is man-made and it can be overcome and eradicated by the actions of human beings. Overcoming poverty is not a gesture of charity. It is an act of justice."
We should heed Mandela's lesson.
This fall we should -- as we can -- commit to ending poverty. And we should do so for the sake of justice.
Michael Elliott is President and CEO of ONE, the global advocacy organization working to end poverty and preventable disease.
This post is part of a series produced by The Huffington Post, "What's Working: Sustainable Development Goals," in conjunction with the United Nations' Sustainable Development Goals (SDGs). The proposed set of milestones will be the subject of discussion at the UN General Assembly meeting on Sept. 25-27, 2015 in New York. The goals, which will replace the UN's Millennium Development Goals (2000-2015), cover 17 key areas of development -- including poverty, hunger, health, education, and gender equality, among many others. As part of The Huffington Post's commitment to solutions-oriented journalism, this What's Working SDG blog series will focus on one goal every weekday in September. This post addresses Goal 1.