Karl Marx was a Jewish, German-born philosopher, economist, political theorist, historian, sociologist, journalist, and revolutionary socialist
Upton Sinclair was a muckraking author whose influential works exposed industrial and socio-political injustices.
Jean-Paul Sartre was a renowned French philosopher, famed for his existentialist thoughts and contributions to 20th-century literature and philosophy.
Friedrich Engels was a German philosopher, historian, and social scientist who co-founded Marxism with Karl Marx, shaping the course of modern socialism.
Antonie Pannekoek was a Dutch astronomer and socialist theorist who made significant contributions to the understanding of the cosmos and the development of Marxist thought.