Internal resistance to the apartheid system in South Africa came from several sectors of society and saw the creation of organizations dedicated variously to peaceful protests, passive resistance and armed insurrection. It came from both black activists like Steve Biko and Desmond Tutu as well as white activists like Harry Schwarz, Joe Slovo and Trevor Huddleston. By the 1980s there was continuous interplay between violent and non-violent action, and this interplay was a notable feature of the rebellion against apartheid from 1983 until South Africa's transition to democracy in 1994.

Although its creation predated apartheid, the African National Congress (ANC) became the primary force in opposition to the government after its conservative leadership was superseded by the organisation's Youth League (ANCYL) in 1949. Led by Walter Sisulu, Nelson Mandela and Oliver Tambo, elected to the ANC's National Executive that year, the ANCYL advocated a radical black nationalist programme which combined the Africanist ideas of Anton Lembede with those of Marxism. They brought the notion that white authority could only be overthrown through mass campaigns.

Apartheid was a system of racial segregation enforced through legislation by the National Party governments, who were the ruling party from 1948 to 1994, of South Africa, under which the rights of the majority black inhabitants of South Africa were curtailed and white supremacy and Afrikaner minority rule was maintained. Apartheid was developed after World War II by the Afrikaner-dominated National Party and Broederbond organizations and was practiced also in South West Africa, which was administered by South Africa under a League of Nations mandate (revoked in 1966), until it gained independence as Namibia in 1990.

Racial segregation in South Africa began in colonial times under Dutch and British rule. However, apartheid as an official policy was introduced following the general election of 1948. New legislation classified inhabitants into four racial groups ("native", "white", "coloured", and "Asian"), and residential areas were segregated, sometimes by means of forced removals. Non-white political representation was completely abolished in 1970, and starting in that year black people were deprived of their citizenship, legally becoming citizens of one of ten tribally based self-governing homelands called bantustans, four of which became nominally independent states. The government segregated education, medical care, beaches, and other public services, and provided black people with services inferior to those of white people.

A practical electrical power source which is a linear electric circuit may, according to Thévenin's theorem, be represented as an ideal voltage source in series with an impedance. This resistance is termed the internal resistance of the source. When the power source delivers current, the measured e.m.f. (voltage output) is lower than the no-load voltage; the difference is the voltage (the product of current and resistance) drop caused by the internal resistance. The concept of internal resistance applies to all kinds of electrical sources and is useful for analyzing many types of electrical circuits.

Batteries can be approximately modeled as a voltage source in series with a resistance. Internal resistance of a battery is dependent on the specific battery's size, chemical properties, age, temperature and the discharge current. Measurement of the internal resistance of a battery is a guide to its condition, but may not apply at other than the test conditions. Internal resistance depends upon temperature; for example, a fresh Energizer E91 AA alkaline primary battery drops from about 0.9 ohms at -40 °C to about 0.1 ohms at 40 °C.

Christopher Eric Hitchens (13 April 1949 – 15 December 2011) was an English American author and journalist whose career spanned more than four decades. Hitchens, often referred to colloquially as "Hitch", was a columnist and literary critic for New Statesman, The Atlantic, The Nation, The Daily Mirror, The Times Literary Supplement and Vanity Fair. He was an author of twelve books and five collections of essays. As a staple of talk shows and lecture circuits, he was a prominent public intellectual, and his confrontational style of debate made him both a lauded and controversial figure.

Hitchens was known for his admiration of George Orwell, Thomas Paine and Thomas Jefferson, as well as for his excoriating critiques of various public figures including Mother Teresa, Bill Clinton, Henry Kissinger and Diana, Princess of Wales. Although he supported the Falklands War, his key split from the established political left began in 1989 after what he called the "tepid reaction" of the Western left to the Rushdie Affair. The September 11 attacks strengthened his internationalist embrace of an interventionist foreign policy, and his vociferous criticism of what he called "fascism with an Islamic face." His numerous editorials in support of the Iraq War caused some to label him a neoconservative, although Hitchens insisted he was not "a conservative of any kind", and his friend Ian McEwan describes him as representing the anti-totalitarian left.

Desmond Mpilo Tutu (born 7 October 1931) is a South African activist and retired Anglican bishop who rose to worldwide fame during the 1980s as an opponent of apartheid. He was the first black South African Archbishop of Cape Town, South Africa, and primate of the Church of the Province of Southern Africa (now the Anglican Church of Southern Africa).

Tutu has been active in the defense of human rights and uses his high profile to campaign for the oppressed. He has campaigned to fight AIDS, tuberculosis, poverty, racism, sexism, homophobia, and transphobia. Tutu received the Nobel Peace Prize in 1984; the Albert Schweitzer Prize for Humanitarianism in 1986; the Pacem in Terris Award in 1987; the Sydney Peace Prize in 1999; the Gandhi Peace Prize in 2005; and the Presidential Medal of Freedom in 2009. Tutu has also compiled several books of his speeches and sayings.

Desmond Mpilo Tutu was born in Klerksdorp, Transvaal, the second of the three children of Zacheriah Zililo Tutu and his wife, Aletta, and the only son. Tutu's family moved to Johannesburg when he was twelve. His father was a teacher and his mother was a cleaner and cook at a school for the blind. Here he met Trevor Huddleston who was a parish priest in the black slum of Sophiatown. "One day," said Tutu, "I was standing in the street with my mother when a white man in a priest's clothing walked past. As he passed us he took off his hat to my mother. I couldn't believe my eyes – a white man who greeted a black working class woman!"