The development of Czech sociology was forcibly interrupted by the Communist coup d'etat of 1948. During the 1950s, the study of sociology, officially branded as a "petit bourgeois pseudoscience," was prohibited. In its place, the Marxist-Leninist doctrine of historical materialism was proclaimed to be the only true social science. Due to a more liberal cultural policy in the 1960s, sociological study again became possible. Most Czech sociologists appeared highly critical, albeit covertly, of dialectical materialism. After the Soviet invasion of 1968, the liberalism came to an end. By 1970, the "ideological purity" of Czech sociology, ie, dialectical materialism, had already been reestablished. The persecution of key sociologists was an essential part of restoring Marxist-Leninist sociology. Modified HA
