A generous and principled giant has died.

Nelson Mandela stood for half a century as a unique example of a selfless leader capable of driving through tough but fair and pragmatic change.

He oppressed no one, forgave much and reached out to all. He helped to bring peace where most had been convinced there would be only conflict. He made possible cooperation and tolerance in a tortured land that had known too much hate and bloodshed.

I was lucky enough to have known and worked with Mandela.

I met him in the early 1990s when he had been released from prison and I was running the Rockefeller Foundation. We worked together on a proposal for a national development bank for South Africa that would have harnessed some of the immense wealth of that country to the task of nation-building and personal opportunity for the majority of South Africans who, for 300 years, had access to neither.

It almost came to pass.

Under the plan, the four giant companies whose combined wealth at that time constituted 80 percent of the value of the Johannesburg Stock Exchange would each “voluntarily” transfer 10 percent of their stock to the new bank, in return for a government commitment of no forced nationalization.

The bank would use the assets to match the savings of any South Africans earning less than a designated amount, allowing them to borrow against those savings for a home mortgage, for the capital to start a new business or to finance higher education for themselves or their children.

Mandela, I learned, focused on you as an individual. It was as if he put his arm around your shoulder and said: “I am walking toward those mountains over there on the horizon.” Even when he was looking you right in the eyes, part of his soul seemed focused on the horizon. Somehow, 27 years of imprisonment had driven out of him all petty emotions. There was no envy, selfishness, annoyance or self-reference. Among the qualities remaining were humility and tenacity.

“If you would like to walk with me, you are welcome to do so for as long or as short a period as you like. I will welcome your company, and we will talk and travel together.”

Mandela accepted you without judgment, as he accepted and befriended his jailers on Robben Island. “But you must know that when you leave me I shall go on. I shall continue on my path toward those far mountains, one step at a time – for as many steps and as long a time as may be required.”

We lost the proposal for the National Development Bank in the end because of a very human incident.

Mandela was to meet with the first President George Bush in Washington. We had done the preparatory work to ensure the Bush team was aware of the proposal and saw it as a useful way the international community could contribute to broad and fair investment in the new, multi-racial South Africa. The plan was for Mandela to ask Bush to lead the G7 in helping to capitalize the bank.

Bush and Mandela had not met before, so their meeting began with chit-chat about their backgrounds. At some point – I never learned exactly what it was – Bush said something that set Mandela off on a long discourse about racism and the problems of South Africa. It was so long, in fact, that it took up the entire meeting. The White House staffer who was present called me afterward and said, “Peter, we were ready to catch the ball, but your man never threw it.”

By such unplanned turns in the chemistry of two individuals is history sometimes formed.

Mandela’s generosity of spirit and his capacity to transcend rancor and racism were the powerful and virtually miraculous tools that helped South Africa stagger onto the road of cooperation and co-existence between people who had hated, demonized and fought each other. That, and the remarkable partner he had in Frederik De Klerk, the Afrikaans prime minister who freed Mandela and met him halfway in their bold experiment in reconciliation.

Mandela did not “have greatness thrust upon him,” as is said so often of other leaders who emerge at key turning points in history. He could well have come away from Robben Island a broken, insignificant man whom history had passed by. Consider the resilience, the persistence and the openness of spirit it required for him to grow stronger and wiser and more effective over those 27 years.

Mandela found greatness within himself and was able to nurture it, to temper it, to humanize it so that when he was invited at last to walk out of prison onto the wide, noisy stage of history he could stand as one of the most remarkable leaders of his period – indeed, of any period in human history.

Now he goes to his grave in peace, with dignity, with the affection of all his countrymen and the respect of the entire world.

And the rest of us lose one of the great figures of our age and one of the most powerfully inspiring examples of what principle and leadership can mean.