The contemporary proletariat is heterogeneous, consisting of the working class of the socialist countries, the capitalist countries and the countries that have shaken off the yoke of colonialism. In this huge army of labour an important place is occupied by the numerically large working class of the capitalist countries, which still has to fulfil its great liberating mission. In this chapter we shall deal primarily with this contingent of workers, with its aims and tasks and with the conditions and difficulties of its selfless struggle against capitalism. Inasmuch as this struggle is being waged under conditions of contemporary capitalism, let us start with an analysis of these conditions and show the essence of contemporary capitalism.