 A number of biographical features may be identified as having a particular influence upon Popper’s thought. His teenage flirtation with Marxism left him thoroughly familiar with the Marxian dialectical view of economics, class-war, and history. But he was appalled by the failure of the democratic parties to stem the rising tide of fascism in Austria in the 1920s and 1930s, and the effective welcome extended to it by the Marxists, who regarded fascism as a necessary dialectical step towards the implosion of capitalism and the ultimate victory of communism. The Poverty of Historicism (1944; 1957) and The Open Society and Its Enemies (1945), Popper’s most impassioned and influential social works, are powerful defences of democratic liberalism, and strident critiques of philosophical presuppositions underpinning all forms of totalitarianism.