In political science, a revolution (Latin: revolutio, 'a turn around') is a rapid, fundamental transformation of a society's class, state, ethnic, or religious structures. According to the sociologist Jack Goldstone, all revolutions contain "a common set of elements at their core: (a) efforts to change the political regime that draw on a competing vision (or visions) of a just order, (b) a notable degree of informal or formal mass mobilization, and (c) efforts to force change through noninstitutionalized actions such as mass demonstrations, protests, strikes, or violence."
Revolutions have occurred throughout human history and varied in their methods, durations and outcomes. Some revolutions started with peasant uprisings or guerrilla warfare on the periphery of a country; others started with urban insurrection aimed at seizing the country's capital city. Revolutions can be inspired by the rising popularity of certain political ideologies, moral principles, or models of governance such as nationalism, republicanism, egalitarianism, self-determination, human rights, democracy, liberalism, fascism, or socialism. A regime may become vulnerable to revolution due to a recent military defeat, or economic chaos, or an affront to national pride and identity, or persistent repression and corruption. Revolutions typically trigger counter-revolutions which seek to halt revolutionary momentum, or to reverse the course of an ongoing revolutionary transformation. Autocracies that take power during revolutions tend to be exceptionally durable and long-lasting.
Notable revolutions in recent centuries include the American Revolution (1765–1783), French Revolution (1789–1799), Haitian Revolution (1791–1804), Spanish American wars of independence (1808–1826), Revolutions of 1848 in Europe, Mexican Revolution (1910–1920), Xinhai Revolution in China in 1911, Revolutions of 1917–1923 in Europe (including the Russian Revolution and German Revolution), Chinese Communist Revolution (1927–1949), Indian independence movement (1885–1947), decolonization of Africa (mid-1950s to 1975), Algerian War of Independence (1954–1962), Cuban Revolution in 1959, Iranian Revolution and Nicaraguan Revolution in 1979, worldwide Revolutions of 1989, and Arab Spring in the early 2010s.
The French noun revolucion traces back to the 13th century, and the English equivalent "revolution" to the late 14th century. The word was limited then to mean the revolving motion of celestial bodies. "Revolution" in the sense of abrupt change in a social order was first recorded in the mid-15th century. By 1688, the political meaning of the word was familiar enough that the replacement of James II with William III was termed the "Glorious Revolution".
"Revolution" is now employed most often to denote a change in social and political institutions. Jeff Goodwin offers two definitions. First, a broad one, including "any and all instances in which a state or a political regime is overthrown and thereby transformed by a popular movement in an irregular, extraconstitutional or violent fashion". Second, a narrow one, in which "revolutions entail not only mass mobilization and regime change, but also more or less rapid and fundamental social, economic or cultural change, during or soon after the struggle for state power".
Jack Goldstone defines a revolution thusly:
[Revolution is] an effort to transform the political institutions and the justifications for political authority in society, accompanied by formal or informal mass mobilization and noninstitutionalized actions that undermine authorities. This definition is broad enough to encompass events ranging from the relatively peaceful revolutions that toppled communist regimes to the violent Islamic revolution in Afghanistan. At the same time, this definition is strong enough to exclude coups, revolts, civil wars, and rebellions that make no effort to transform institutions or the justification for authority.
Goldstone's definition excludes peaceful transitions to democracy through plebiscite or free elections, as occurred in Spain after the death of Francisco Franco, or in Argentina and Chile after the demise of their military juntas. Early scholars often debated the distinction between revolution and civil war. They also questioned whether a revolution is purely political (i.e., concerned with the restructuring of government) or whether "it is an extensive and inclusive social change affecting all the various aspects of the life of a society, including the economic, religious, industrial, and familial as well as the political".
There are numerous typologies of revolution in the social science literature. Alexis de Tocqueville differentiated between:
sudden and violent revolutions that seek not only to establish a new political system but to overhaul an entire society, and;
slow and relentless revolutions that involve sweeping transformations of the entire society and may take several generations to bring about (such as changes in religion).
One of the Marxist typologies divides revolutions into:
Charles Tilly, a modern scholar of revolutions, differentiated between:
coup d'état (a top-down seizure of power), e.g., Poland, 1926
"great revolution" (a revolution that transforms economic and social structures as well as political institutions, such as the French Revolution of 1789, Russian Revolution of 1917, or Islamic Revolution of Iran in 1979).
Mark Katz identified six forms of revolution:
coup d'état, e.g., Egypt, 1952
revolution from above, e.g., Mao Zedong's Great Leap Forward of 1958