Nelson Mandela's legacy to the world is the subject of a book launched in Johannesburg on Wednesday, the week before Mr Mandela's 88th birthday.
Veteran photographers Alf Khumalo (r) and Jurgen Schadeberg (l) were at the launch
The Meaning of Mandela brings together three lectures given last year by Nigerian Wole Soyinka, and US thinkers Henry Louis Gates and Cornel West.
The event also marked the launch of a photo exhibition on political resistance in 1950s South Africa.
As a young lawyer, Mr Mandela helped plan a campaign against racist laws.
Xolela Mangcu, who convened the lectures and edited the book, said part of the purpose of the exercise was to thank Mr Mandela for the gift of freedom.
"Speaking for those of the younger generation, I cannot imagine a greater gift than that."
Dr Mangcu said it had been a conscious decision not to include South African writers in the latest lecture series and book.
"I felt that we often get bogged down in our petty differences," he explained.
He added though that the project of defining the meaning of Mandela would continue, and that South Africans would be asked to participate in future.
The exhibition mounted by the Nelson Mandela Foundation in Johannesburg documents the 1952 defiance campaign, when the ANC led a campaign of resistance against racially discriminatory laws.
It features the work of veteran photographers Alf Khumalo and Jurgen Schadeberg.
Alf Khumalo recalled an incident when he was photographing Mr Mandela during a trip to the United States in the 1990s.
"He told some people, 'This is Alf Khumalo, my colleague, he was also in jail'.
"Then everybody wanted to pose with me," Mr Khumalo said. "Mandela didn't mention I'd been to jail several times but for very short stints."
Mr Schadeberg said that although in the 1950s Mr Mandela was one among many notable anti-apartheid leaders, it was his serenity that left an impression.
"At the time there were a lot of great people around - many of them would be come very agitated but he was always in control - even now, you can see that he is calm, a man of peace," Mr Schadeberg said.