Extremist in the context of "Fundamentalism"

The Nazi Party, officially the National Socialist German Workers' Party (German: Nationalsozialistische Deutsche Arbeiterpartei  or NSDAP), was a far-right political party in Germany active between 1920 and 1945 that created and supported the ideology of Nazism. Its precursor, the German Workers' Party (Deutsche Arbeiterpartei; DAP), existed from 1919 to 1920. The Nazi Party emerged from the extremist German nationalist ("Völkisch nationalist"), racist, and populist Freikorps paramilitary culture, which fought against communist uprisings in post–World War I Germany. The party was created to draw workers away from communism and into völkisch nationalism. Initially, Nazi political strategy focused on anti-big business, anti-bourgeoisie, and anti-capitalism, disingenuously using socialist rhetoric to gain the support of the lower middle class; that was later downplayed to gain the support of business leaders. By the 1930s, the party's main focus shifted to antisemitic and anti-Marxist themes. The party had little popular support until the Great Depression, when worsening living standards and widespread unemployment drove Germans into political extremism.

Central to Nazism were themes of racial segregation expressed in the idea of a "people's community" (Volksgemeinschaft). The party aimed to unite "racially desirable" Germans as national comrades while excluding those deemed to be either political dissidents, physically or intellectually inferior, or of a foreign race (Fremdvölkische). The Nazis sought to strengthen the Germanic people, the "Aryan master race", through racial purity and eugenics, broad social welfare programs, and a collective subordination of individual rights, which could be sacrificed for the good of the state on behalf of the people. To protect the supposed purity and strength of the Aryan race, the Nazis sought to disenfranchise, segregate, and eventually exterminate Jews, Romani, Slavs, the physically and mentally disabled, homosexuals, Jehovah's Witnesses, and political opponents. The persecution reached its climax when the party-controlled German state set in motion the Final Solution – an industrial system of genocide that carried out mass murders of around 6 million Jews and millions of other targeted victims in what has become known as the Holocaust.

Essentialism is the view that objects have a set of attributes that are necessary to their identity. In early Western thought, Platonic idealism held that all things have such an "essence"—an "idea" or "form". In Categories, Aristotle similarly proposed that all objects have a substance that, as George Lakoff put it, "make the thing what it is, and without which it would be not that kind of thing". The contrary view—non-essentialism—denies the need to posit such an "essence". Essentialism has been controversial from its beginning. In the Parmenides dialogue, Plato depicts Socrates questioning the notion, suggesting that if we accept the idea that every beautiful thing or just action partakes of an essence to be beautiful or just, we must also accept the "existence of separate essences for hair, mud, and dirt".

Older social theories were often conceptually essentialist. In biology and other natural sciences, essentialism provided the rationale for taxonomy at least until the time of Charles Darwin. The role and importance of essentialism in modern biology is still a matter of debate. Beliefs which posit that social identities such as race, ethnicity, nationality, or gender are essential characteristics have been central to many discriminatory or extremist ideologies. For instance, psychological essentialism is correlated with racial prejudice. Essentialist views about race have also been shown to diminish empathy when dealing with members of another racial group. In medical sciences, essentialism can lead to a reified view of identities, leading to fallacious conclusions and potentially unequal treatment.

Ultranationalism, or extreme nationalism, is an extremist form of nationalism in which a country asserts or maintains hegemony, supremacy, or other forms of control over other nations (usually through violent coercion) to pursue its specific interests. Ultranationalist entities have been associated with the engagement of political violence even during peacetime.

In ideological terms the British political theorist Roger Griffin said that ultranationalism arises from seeing modern nation states as living organisms, and that in stark mythological ways, political campaigners have divided societies into those that are perceived as being degenerately inferior and those perceived as having great cultural destinies. Ultranationalism has been an aspect of fascism, with historic governments such as the regimes of Fascist Italy and Nazi Germany building on ultranationalist foundations by using specific plans for supposed widespread national renewal. Another major example was the Khmer Rouge regime in Democratic Kampuchea (Cambodia) that promoted ultranationalism.

Far-left politics are politics further to the left on the political spectrum than the standard political left. In certain instances—especially in the news media—far left has been associated with various forms of authoritarianism, anarchism, communism, and Marxism, or are characterised as groups that advocate for revolutionary socialism and related communist ideologies, or anti-capitalism and anti-globalisation. Far-left terrorism consists of extremist, militant, or insurgent groups that attempt to realise their ideals through political violence rather than using democratic processes.