On a cold, wintry, rainy day in London, Nelson Mandela rejected a suggestion by his wife Winnie to fetch his raincoat from his hotel room.

Mandela was in the hotel lobby, on his way to meet "The Iron Lady" Margaret Thatcher during his international tour after his release from prison.

Going back to his room would have delayed him. "I am a stickler about punctuality not only because I think it is a sign of respect to the person you are meeting but in order to combat the Western stereotype of Africans as being notoriously tardy," Mandela remarked in his autobiography Long Walk to Freedom.

Mandela's presidency would in part be driven by the need to demonstrate that, contrary to racist beliefs, Africans were capable of running a modern political system and a sophisticated economy. They were not "notoriously tardy", a metaphor for incompetence.

To harp on the cliché, Mandela was no saint. But he was politically mature enough to understand that mere ascendancy to the Union Buildings was a tiny step to the mission to prove Western notions of Africans wrong.

Failure to do so would have meant the betrayal of the core of the struggle for freedom - that Africans are equally capable to lead and govern.

The idea that blacks must prove that they are not tardy (read: incompetent) in relation to whites is very irritating. But it is a necessary irritation. The attainment of freedom did not mean that all ill-conceived myths about Africans miraculously disappeared.

With freedom came an opportunity and responsibility to debunk the stereotypes that for centuries formed the basis of racial discrimination against Africans. It would be foolish to leave them unchallenged.

But deeds, not mere talk, are a powerful instrument to confront such stereotypes. And it takes high-level political consciousness for an African leader to appreciate that beyond the legal duty to govern well there is a moral and historic obligation to prove that he is capable.

Not only to prove his own capability, but that his own race group is not what the colonisers and the architect of apartheid had in mind.

An African leader, therefore, would necessarily have the moral responsibility, in action and rhetoric, to represent his people to undermine racism and its vestiges.

Any sign of racial stereotypes against Africans needed to be dealt with. Thabo Mbeki's presidency was also in part driven by this. His battle to prove black excellence often got him into trouble with people who accused him of being obsessed with race.

But Mandela and Mbeki shared the same goal of confronting anything that might entrench racial stereotypes against Africans.

So conscious was Mbeki of racial stereotypes that he once reacted angrily to a suggestion in 1997 by Conrad Strauss, chairman of the South African Foundation, a business lobby group, for business to second senior executives to help the government beef up its capacity.

"Had Mbeki heard, in his offer of help, a criticism of his own ability to run things, and thus - once more - the arrogance of white people who could not let go of the belief that blacks were not up to the job [of governing]?" asks Mark Gevisser in Dream Deferred, a biography on Mbeki.

Like Mandela, Mbeki possessed a high level of political consciousness, which dictated that in action and rhetoric he needed to show that Africans were capable.

Mbeki took it further and launched a continent-wide campaign on the African renaissance - a partly black consciousness and pan-African project. The campaign was institutionalised in the New Partnership for Africa's Development, among other projects.

The need to fight racial stereotypes by proving others wrong with your own capabilities was not new. When the Afrikaners were still impoverished, the vice chancellor of the University of Cape Town Sir Robert Beattie suggested that there was something inherently wrong with them that made them intellectually backward.

In the early 1950s, Anton Rupert, a successful Afrikaner industrialist and founder of Rembrandt responded to the accusation, saying his success had defeated the illusion that Afrikaners could not compete with their English and Jewish compatriots.

"It was essential that someone broke down the illusion," he is quoted saying in his biography.

It is clear that the need to prove others wrong by doing the right thing and showing your true capabilities can bear fruit. Rupert was not the only Afrikaner to "break down" the race-related illusion.

In a way, Mandela and Mbeki were of the same mind in relation to their approach to political life and political office. They knew that the struggle was not about being ushered into higher office or the ululations that come with it; it was about what they could do with political office to pursue the moral essence of the struggle.

In spite of their mistakes, nothing they did revealed lack of appreciation of the need to show that Africans are capable. They were not notoriously incompetent. If anything, they notoriously defied racist stereotypes. It's important that this defiance continues and be seen to continue.