Photo gallery: 17th Nelson Mandela Annual Lecture

"Injustice is unsustainable!" - South Africa's Chief Justice Mogoeng Mogoeng. (Image: Nelson Mandela Foundation)

Foundation Chairman Njabulo Ndebele arriving at the University of Johannesburg's Soweto campus for the lecture. (Image: Nelson Mandela Foundation)

Karin April and Hans Beuhler of the Hans Seidell Foundation, one of the sponsors of this year's Nelson Mandela Annual Lecture. (Image: Nelson Mandela Foundation)

Guests who attended the lecture. (Image: Nelson Mandela Foundation)

Guests at the lecture. (Image: Nelson Mandela Foundation)

Ndileka Mandela, Nelson Mandela's oldest grandchild. (Image: Nelson Mandela Foundation)

From left: Chair of the Nelson Mandela Foundation Professor Njabulo Ndebele, Chief Justice Mogoeng Mogoeng and Chief Executive of the Nelson Mandela Foundation Sello Hatang. (Image: Nelson Mandela Foundation)

From left: Former leader of the Inkatha Freedom Party and Member of Parliament Mangosuthu Buthelezi and chair of the Nelson Mandela Foundation, Professor Njabulo Ndebele. (Image: Nelson Mandela Foundation)

Foundation Chief Executive Sello Hatang, opening the lecture. (Image: Nelson Mandela Foundation)

Foundation Trustee Dr Ramphela Mamphele, on stage at the lecture. (Image: Nelson Mandela Foundation)

Phemelo Motene, the MC of the 17th Nelson Mandela Annual Lecture (right), with the sign language interpreter (left). (Image: Nelson Mandela Foundation)

The Soweto Gospel Choir performed at the event. (Image: Nelson Mandela Foundation)

South Africa's Chief Justice Mogoeng Mogoeng, delivering the 17th Nelson Mandela Annual Lecture. (Image: Nelson Mandela Foundation)