About 100 heads of state and other world leaders mourned the death of Nelson Mandela at a memorial service for the former South African president in Johannesburg on Tuesday, showing how Mandela was revered all around the world.

Mandela, a Nobel Peace Prize laureate honored for his strenuous fight against apartheid and eventual success in ending his country's system of racial segregation, died last Thursday. He was 95.

The global dignitaries at the national memorial service held for Mandela at a stadium in South Africa's largest city included Crown Prince Naruhito and former Prime Minister Yasuo Fukuda. In a memorial address, President Barack Obama praised the anti-apartheid icon's achievements, describing him as "a giant of history, who moved a nation toward justice and in the process moved billions around the world."

During the second half of the 20th century, Afrikaner whites, the South African minority that ruled the country, repressed the black majority under legislation based on apartheid. Black members of the population did not possess the right to vote and were even restricted in where they could live.

A lawyer, Mandela fought racial discrimination in his country after joining the anti-apartheid activities of the African National Congress, then a political party struggling for the freedom of black South Africans. Mandela's adherence to his cause despite 27 years in prison for treason provokes amazement.

The true worth of Mandela's political leadership was demonstrated when and after he was asked by his nation's white government to help end apartheid. By that time, the South African government could no longer endure the international sanctions imposed on the country.

Mandela ended the ANC's pursuit of an armed struggle and negotiated with the white government, which resulted in an end to apartheid and a national election open to all races. This enabled the ANC to take the reins of government, with Mandela becoming South Africa's first black president. However, he urged the black majority not to retaliate against whites.

In his inaugural address as South African president in 1994, Mandela pledged to "build the society in which all South Africans, both black and white, will be able to walk tall, without any fear in their hearts." In fact, the position of vice president was assumed by Mandela's predecessor, a white president.

Mandela's spirit of tolerance — with which he sought to transform South Africa into a nation in which all ethnic groups could live in harmony — deeply affected people around the world.

In 1995, South Africa hosted the rugby World Cup. Mandela cheered for his country's national team, which comprised mostly white players — an episode that helped create a sense of unity among South Africans. The story was later made into an American film that became known to many people around the world.

Mandela's achievements also included his successful post-apartheid economic policies, which included efforts to skillfully utilize the vitality of white industrialists instead of depriving them of management rights. He did not persist in his own view that his country's mines should be placed under state control. All this contributed to economic growth.

However, today South Africa seems to be experiencing what may be regarded as the adverse effects of the ANC's prolonged rule, including corruption within its administration and abuse of privilege. Little progress has been made in narrowing economic disparities between the white minority and the black majority.

Ethnic conflicts and bloodshed attributable to religious differences continue to rage in many parts of the world. Not only South Africans but also people around the world must remind themselves of the precious lessons taught by Mandela.