Antonio Negri is best known as one of the authors of Empire, a terrible tome that became popular for a minute among trendy First Worldists. However, Negri is also known for his theory of the social factory. According to Antonio Negri, there are three distinct phases of capitalist development. And, along with these phases, three distinct types of working class. The “professional worker” is the first type. The “professional worker” is the main form from the middle of the nineteenth century to the outbreak of the World Wars. The second type is the “mass worker.” The “mass worker” is the main type from 1918 to the late 1960s. The third, contemporary type is the “socialized worker.”