Five months after Duma Kumalo's death sentence was commuted, he sat on a hard prison chair and laughed. That laughter, he believes, saved him from being consumed by hatred for his captors.
"There was a lot of anger in me. But then I started laughing at the terrible things that had happened to me. I realised that, if I could survive those, there wasn't anything in life I couldn't deal with."
In 1985, Mr Kumalo was sentenced to death in a South African jail, for a murder he did not commit. The sentence was commuted three hours before he was due to be hanged. Now his story is being told, along with those of 26 others, as part of a touring exhibition.
The F Word: Images of Forgiveness combines photographs and personal testimonies from people whose lives have been affected by violence or injustice. These include Berthe and Francis Climbie, whose seven-year-old daughter Victoria was murdered; Marian Partington, whose sister was murdered by Fred West; and Mariane Pearl, widow of Daniel Pearl, the journalist killed by Pakistani terrorists.
There are also testimonies from convicted murderers and terrorists, demonstrating how the perpetrators of violence can also be affected by their actions. Marina Cantacuzino, who developed the exhibition, hopes that the stories will emphasise the importance of dialogue, by offering the human face of violence.
"We're turning revenge on its head, and not accepting hatred," she said.
"It's an insight into human behaviour, giving an understanding of what makes people do what they do."
Brian Moody, the photographer who worked with Ms Cantacuzino, said: "These are people who have managed to come through introspection and hate, to move on to something more positive. You have to defer to their experience."
But forgiveness is not always a desirable, or even realistic goal. The exhibition therefore includes stories of those unable to come to terms with the wrongs they have suffered. The mother of an IRA victim talks of her desire to kill the children of her son's murderers, while a survivor of the Chernobyl nuclear disaster says: "I do not forgive those responsible. Would you?"
"Forgiveness is an incredibly complex thing, that you don't necessarily arrive or stay at," said Ms Cantacuzino. "I hope visitors to the exhibition will talk about how important rage and anger are, as well."
In particular, she hopes that the exhibition will be used by schools as a springboard for citizenship discussions, questioning the desirability of forgiveness, and whether some crimes are unforgivable.
Duma Kumalo believes that it is vital for children to learn about the suffering of others. "The past is contained in the present," he said. "If we don't talk about what happened, it will happen again. Talk can prevent wars."