Final answer:
Karl Marx developed the concept of communism and the theory of the class struggle, as well as critiquing capitalism and describing false consciousness and alienation in a capitalist society.
Step-by-step explanation:
Karl Marx, a German philosopher and economist, developed the concept of communism along with the related theories of socialism, class struggle, and the critique of capitalism. He believed in the proletariat's inevitable overthrow of the ruling class, or bourgeoisie, leading to a socialist state and eventually a classless, communist society. Marx's ideas also included the concept of false consciousness, where the working class's perspective is manipulated to align with the interests of the ruling class. He considered this to be an obstacle to class consciousness, which he saw as essential for the proletariat to recognize its role in the revolution. Furthermore, Marx addressed the issue of alienation in capitalism, where individuals become estranged from their human essence and collective identity.