Radical politics denotes the intent to transform or replace thefundamental principles of asociety orpolitical system, often throughsocial change,structural change,revolution or radicalreform.^[1] The process of adopting radical views is termedradicalisation.

The wordradical derives from theLatinradix ("root") andLate Latinradicalis ("of or pertaining to the root, radical"). Historically, political use of the term referred exclusively to a form ofprogressiveelectoral reformism, known asRadicalism, that had developed in Europe during the 18th and 19th centuries. However, the denotation has changed since its 18th century coinage to comprehend the entirepolitical spectrum, though retaining the connotation of "change at the root".^[1]

TheOxford English Dictionary traces usage of 'radical' in a political context to 1783.^[2] TheEncyclopædia Britannica records the first political usage of 'radical' as ascribed toCharles James Fox, aBritish Whig Partyparliamentarian who in 1797 proposed a 'radical reform' of theelectoral system to provideuniversal manhood suffrage, thereby idiomatically establishing the term 'Radicals' as a label denoting supporters of the reformation of British Parliament.^[3]

Throughout the 19th century, the concept of radical politics broadened into a variety of political notions and doctrines.Party politics in England began to favour moderate positions, marginalising other movements into more politically aggressive factions.^{[citation needed]} As open advocacy ofrepublicanism was illegal inFrance following theNapoleonic Wars, Radicals emerged under similar reformist ideals as their British counterparts, though they later branched out to form theRadical-Socialist movement with a focus on proletarian solidarity.^[3][4] With the rise ofMarxism, the notion of radical politics shifted away from reformism and became more associated with revolutionary politics.^[3] InUnited States politics, the term is usedpejoratively amongconservatives andmoderates to denote politicalextremism,^[3][5] with the 19th-centuryCyclopaedia of Political Science describing it as "characterized less by its principles than by the manner of their application".^[6]

During the 20th century, radical politicians took power in many countries across the world. Such radicalleaders includedVladimir Lenin andJoseph Stalin in Russia,Mao Zedong in China,Ruhollah Khomeini in Iran,Adolf Hitler in Germany, as well as more mainstream radicals such asRonald Reagan in the United States andMargaret Thatcher in the United Kingdom.^[1][7]

The common feature to all radical political forms is a view that some fundamental change is required of thestatus quo. For an array ofanti-capitalist forms, this manifests inanti-establishment reactions to modernneoliberal regimes.^[1]

TheStanford Encyclopedia of Philosophy describes the radical concept ofideology to be that:

• Whilesocial conditions exist "that are vulnerable to criticism and protest; ideology exists to protect these social conditions from attack by those who aredisadvantaged by them."^[8]
• "Ideology conserves by camouflaging flawed social conditions, giving an illusory account of their rationale or function, in order tolegitimate and win acceptance of them."^[8]

This view reflects "a consensus among radicals of all stripes on the role of law as adissembling force to safeguard the unjust relations of the status quo."^[8] This radical critique of ideology is especially prominent withinpost-leftism.^[9] In addressing specific issues, some radical politics may completely forgo any overarching ideological plan.^[1]

Astrid Bötticher identifies several differences between radicalism andextremism, among them in goals (idealistic vs.restorative, emancipatory vs. anti-democratic), morals (particular vs. universal), approach towards diversity (acceptance vs. disdain), and use of violence (pragmatic and selective vs. legitimate and acceptable).^[10]

• The M and S Collection at theLibrary of Congress contains materials on radical movements.