The events of the first half of the twentieth century are seen quite differently today from the way they were seen at the time. Historians describe the period between 1914 and 1945 as a birth of mass culture, resulting in fresh forms of popular expression. During World War I and II, the making of masses into a historically powerful force was the most significant event of this time period. The rise of masses heralded the onset of a new phase of culture in which ordinary men and women from the lower middle class and the working class challenged bourgeois dominance in such the same way that the bourgeoisie had earlier challenged and eventually overcome the aristocracy. Mass culture triggered negative responses in most serious artists, writers, and musicians, who preferred the difficult and somewhat remote style of Modernism. The leaders of Modernism, partly because of the extreme popularity of mass culture, now fashioned works that grew more and more revolutionary in form, constantly testing the limits of the arts. Modernism is a reflection of the fast paced modern world whose foundations and boundaries seemed to constantly shifting. The period between 1914 and 1945 thus saw both the rise of mass culture and the zenith of Modernism. Before World War I, liberal values guided most people's expectations. However, between the outbreak of World War I and World War II the values of liberalism were severely tested and in some cases overthrown. To those who clung to liberal ideas, the world had seemed to go mad. In a painting by Pablo Picasso titled Guernica, Picasso paints a vivid symbol of the violent twenty years between World War I and World War II. Depicting the bombing of the unarmed town of Guernica by Nazi planes during the Spanish Civil War, the painting transforms the local struggle into an international battle between totalitarianism and human freedom-the issue that also dominated the age's ideological debates.