Ernst Simon Bloch (ɛʁnst ˈblɔx; July 8, 1885 – August 4, 1977; pseudonyms: Karl Jahraus, Jakob Knerz) was a German Marxist philosopher. Bloch was influenced by Georg Wilhelm Friedrich Hegel and Karl Marx, as well as by apocalyptic and religious thinkers such as Thomas Müntzer, Paracelsus, and Jacob Böhme. He established friendships with György Lukács, Bertolt Brecht, Kurt Weill, Walter Benjamin, and Theodor W. Adorno. Bloch's work focuses on an optimistic teleology of the history of mankind.
Bloch was born in Ludwigshafen, the son of a Jewish railway employee. After studying philosophy, he married Else von Stritzky, daughter of a Baltic brewer in 1913, who died in 1921. His second marriage with Linda Oppenheimer lasted only a few years. His third wife was Karola Piotrowska, a Polish architect, whom he married in 1934 in Vienna. When the Nazis came to power, the couple had to flee, first into Switzerland, then to Austria, France, Czechoslovakia, and finally the United States. He lived briefly in New Hampshire before settling in Cambridge, Massachusetts. It was there, in the reading room of Harvard's Widener Library, that Bloch wrote the lengthy three-volume work The Principle of Hope. He originally planned to publish it there under the title Dreams of a Better Life.
In 1948, Bloch was offered the chair of philosophy at the University of Leipzig, and he returned to East Germany to take up the position. In 1955 he was awarded the National Prize of the GDR. In addition, he became a member of the German Academy of Sciences at Berlin (AdW). He had more or less become the political philosopher of the GDR. Among his many academic students from this period was his assistant Manfred Buhr, who earned his doctorate with him in 1957, and was later a professor in Greifswald, then director of the Central Institute of Philosophy of the Academy of Sciences (ADC) in Berlin and who became a critic of Bloch.
However, the Hungarian uprising in 1956 led Bloch to revise his view of the SED (Socialist Unity Party) regime, whilst retaining his Marxist orientation.