President Cyril Ramaphosa used the Raymond Mhlaba memorial lecture to issue a wake-up call to those who still believe apartheid was not a crime against humanity.
Delivering his speech at the lecture in Vryheid, KwaZulu-Natal, the president said: "The unity of the people of South Africa, black and white, is being undermined by those who perpetuate the false and backward notion of white supremacy which manifests itself in sporadic rants of racial bigotry."
"Also undermining the unity of South Africans are those who work hard to conceal, rather than confront,, their own racial prejudices. These often hide their racism under the guise of critical intellectual engagement and freedom of speech."
Ramaphosa said these people sought to manipulate memories of the apartheid past and present apartheid as having been less than what it was.
"Apartheid was a crime against humanity and against the people of SA."
The president's comments came after a public outcry in Parliament last week when apartheid president FW de Klerk was invited to the State of the Nation Address after he said in an interview that apartheid was not a crime against humanity.
The memorial lecture was held to honour "Oom Ray"- a struggle icon in the ANC who would have turned 100 this year.
Ramaphosa said Mhlaba Ray belonged to a special generation of leaders who charted the path to freedom.
Turning to the scourge of corruption, the president said: "Another affront to the vision and legacy of Mhlaba and his comrades is the issue of corruption."
He said corruption and the associated phenomenon of state capture were obstacles to the achievement of radical economic transformation.
Mentioning a few other struggle icons in his speech, including former president Nelson Mandela, Harry Gwala, Chief Albert Luthuli, Ramaphosa said gender-based violence (GBV) undermined Mhlaba's vision for a non-sexist society.
He called on men to change their behaviour and attitudes and to see women as equal human beings.
"Women of South Africa are not second-class citizens of the Republic of South Africa, nor are they children who need a guardian or father figure making decisions for them."
The president added that men in South Africa should treat women with the respect and honour that they deserve because they are mothers, sisters, aunts and grandmothers.
He thanked the Mhlaba family for allowing their son to be a part of the struggle.