The authoritarian, ultranationalist tradition that emerged in early twentieth-century Europe — first as Mussolini's Italian Fascism, then in its most radical form as German National Socialism — fusing nation, state and leader into a single organic whole and seeking national rebirth through will, discipline and violence.
Its intellectual roots run through Georges Sorel's myth of revolutionary violence, Giovanni Gentile's actual idealism, written to supply the Italian regime with a philosophy, and a wider anti-liberal current taking in Carl Schmitt's decisionism and Julius Evola's radical Traditionalism. Fascism rejected liberal individualism, parliamentary procedure and Marxist class analysis together, replacing them with hierarchy, myth, and the leader as the nation's embodied will. Mussolini took power in 1922; the German regime that followed added a biological racism that Italian Fascism had not originally contained and that culminated in industrialized extermination.
Scholars disagree about what fascism essentially was. Roger Griffin's influential definition centers on palingenetic ultranationalism — the myth of national rebirth from decadence. Robert Paxton argued instead that fascism had no stable doctrine to define, and must be understood through its mobilizing passions and its stages of development, since what it said varied with what it needed. The dispute is not academic: it determines what counts as an instance.
It is studied primarily as a historical tradition, its regimes defeated by 1945, and its themes recur in contemporary far-right and authoritarian-nationalist movements. Whether the word applies to those movements is genuinely contested among specialists — the case for is thematic continuity, the case against is that fascism was a product of mass mobilization, total war and a specific interwar crisis, and that using the term as a general insult has cost it most of its analytical precision.