Karl Marx developed a theory of history and society known as historical materialism or Marxism. He argued that history is defined by class struggle between economic classes, and that capitalist societies would inevitably give way to socialist ones due to internal contradictions like alienation of workers and tendency towards crisis. While capitalism created massive productive forces, it also created inequality and instability. Marx saw it as the precursor to socialism and eventually communism, without private ownership and class divisions. His theories were influential but faced criticisms around human nature and whether revolution was necessary. Debate continues around the ongoing relevance of Marx's critique of capitalism.