powerful impetus by fall of the Kaiser and royal power. In response to the shortage of pre-war accommodation and housing, tenements were built not far from the Kaiser's Stadtschloss and other majestic structures erected in honor of former nobles. Average people began using their backyards and basements to run small shops, restaurants, and workshops. Commerce expanded rapidly, and included the establishment of Berlin's first department stores, prior to World War I. An "urban petty bourgeoisie" along with a growing middle class grew and flourished in wholesale commerce, retail trade, factories and crafts. Types of employment were becoming more modern, shifting gradually but noticeably towards industry and services. Before World War I, in 1907, 54.9% of German workers were manual labourers. This dropped to 50.1% by 1925. Office workers, managers, and bureaucrats increased their share of the labour market from 10.3% to 17% over the same period. Germany was slowly becoming more urban and middle class. Still, by 1925, only a third of Germans lived in large cities; the other two-thirds of the population lived in the smaller towns or in rural areas. The total population of Germany rose from 62.4 million in 1920 to 65.2 million in 1933. The Wilhelminian values were further discredited as a consequence of World War I and the subsequent inflation, since the new youth generation saw no point in saving for marriage in such conditions, and preferred instead to spend and enjoy. According to cultural historian Bruce Thompson, the Fritz Lang movie Dr. Mabuse the Gambler (1922) captures Berlin's postwar mood: Politically and economically, the nation was struggling with the terms and reparations imposed by the Treaty of Versailles (1919) that ended World War I and endured punishing levels of inflation. Sociology During the era of the Weimar Republic, Germany became a center of intellectual thought at its universities, and most notably social and political theory (especially Marxism) was combined with Freudian psychoanalysis to form the highly influential discipline of Critical Theory—with its development at the Institute for Social Research (also known as the Frankfurt School) founded at the University of Frankfurt am Main. The most prominent philosophers with which the so-called 'Frankfurt School' is associated were Erich Fromm, Herbert Marcuse, Theodor Adorno, Walter Benjamin, Jürgen Habermas and Max Horkheimer. Among the prominent philosophers not associated with the Frankfurt School were Martin Heidegger and Max Weber. The German philosophical anthropology movement also emerged at this