The Big Read: Over the next two weeks, South Africans from all walks of life will remember how former State President FW de Klerk took the world by surprise on February 2 1990, unbanning the liberation movements and announcing the release of Nelson Mandela.

On February 11 we will celebrate the 20th anniversary of the culmination of these events, that momentous day when Nelson Mandela was released and addressed a rally in Cape Town, as we took our first tentative steps towards freedom together as a nation.

These were momentous days, filled with both hope and fear as we sought to find our path.

In his first address after being released, Madiba saluted the ranks of all those who had made sacrifices, and paid tribute to all those leaders, both locally and abroad, who assisted in bringing that moment to fruition.

His preliminary remarks were tentative and careful, reflecting the tension between his own efforts and talks with the National Party government and his keen awareness that any leader needs to lead democratically, with full consultation.

Madiba made it clear then that only universal suffrage would be accepted as the basis for any changes.

"Our march to freedom is irreversible," he said.

"We must not allow fear to stand in our way. Universal suffrage on a common voters' roll in a united democratic and non-racial South Africa is the only way to peace and racial harmony."

And this condition was met - spectacularly - when millions of people patiently turned out to vote in non-racial queues on April 27 1994.

As we reflect on these times we need to ask ourselves how we can repay the significant debts we owe Mandela and how we thank him for his visionary leadership.

How do we thank this most remarkable human being for his values-driven leadership and his calming presence during the birth of our nation?

One of the most important debts we owe Mandela is to refuse to allow cynicism about the values we see in public life today to defile and scar the sanctity of the right to vote - a right won with the blood and sacrifice of so many that it must not be allowed to be denigrated by a few opportunistic political figures.

Last week, Winnie Mandela rightly reminded us all that it would sadden Madiba to know the extent to which our politicians, who once saw politics as a path of sacrifice and service and servant leadership, now appear all too keen to climb the greasy pole of careerism and self-aggrandisement.

The significant debt we owe Mandela requires that we reclaim that call to service in public life - a theme that often emerged in the first days of the Zuma administration but has been lost in the cacophony of competing voices that are already agitating for power in 2012.

Our leaders in public and political life owe it to Mandela to reclaim his values, lead in the service of the people and to bring to fruition the constitutional vision of a unified country free of the ghosts of deprivation and abuse that haunt our past and present.

Similarly, our public servants owe a daily debt to Mandela to stop the ethical drift and corruption that appears to have become endemic and, if they are unable to place the people before themselves, will forever defer the dreams of our people.

Our teachers owe Mandela a daily debt to be present for their students - to be in their classes and in their lives in meaningful ways that help them discover talents and find niches in society with which they might effectively contribute to the building of the country they will inherit.

The custodians of government's education policies owe it to Mandela to place the children of our country before unionised interests, policy experiments and self-serving behaviour.

Our born-free generations owe Mandela a special debt to lead us all away from racialised politics, socialisation habits and the trust deficits that hinder our progress as a country.

All South Africans owe Madiba the debt of working towards the vision of a constitutional state, where we strive for a better future under the rubric of the very founding document Mandela signed as president on December 10 1996.

As our Constitution states: "We therefore, through our freely elected representatives, adopt this Constitution as the supreme law of the Republic so as to heal the divisions of that past and establish a society based on democratic values, social justice and fundamental human rights; lay the foundations for a democratic and open society in which government is based on the will of the people and every citizen is equally protected by law; improve the quality of life of all citizens and free the potential of each person; and build a united and democratic South Africa able to take its rightful place as a sovereign state in the family of nations."

And as Ralph Waldo Emerson said about debt: "The whole of what we know is a system of compensations. Each suffering is rewarded; each sacrifice is made up; every debt is paid."

We must work every day to ensure that we pay our debts as a society, ensuring that the legacy of our past is replaced by a legacy of the vision and values of Nelson Mandela.

That will be the only real tribute worthy of the man whose stature and forgiveness sheltered us from the hatred and demons of our past; the man who allowed us to dream that we all belong together, and can build an enduring non-racial and non-sexist democracy out of the ashes of the past.

This is the ultimate debt we need to repay for the gift of his life that he has given so selflessly to us all.

> In The Times on Tuesday, FW de Klerk thinks back on his momentous speech to Parliament twenty years ago.