(D) “How do you justify this distinction between science and philosophy in Marxist theory?”. (R) “I shall answer you by formulating a number of provisional and schematic theses. 1. The fusion of Marxist theory and the Workers’ Movement is the most important event in the whole history of the class struggle, i.e., in practically the whole of human ‘history’ (first effects: the socialist revolutions). 2. Marxist theory (science and philosophy) represents an unprecedented revolution in the history of human knowledge. 3. Marx founded a new science: the science of history. Let me use an image. The sciences we are familiar with have been installed in a number of great ‘continents’. Before Marx, two such continents had been opened up to scientific knowledge: the continent of Mathematics and the continent of Physics. The first by the Greeks (Thales), the second by Galileo. Marx opened up a third continent to scientific knowledge: the continent of History. 4. The opening up of this new continent had induced a revolution in philosophy. That is a law: philosophy is always linked to the sciences. Philosophy was born (with Plato) at the opening up of the continent of Mathematics. It was transformed (with Descartes) by the opening up of the continent of Physics. Today it is being revolutionized by the opening up of the continent of History by Marx. This revolution is called dialectical materialism” [Louis Althusser, Philosophy as a Revolutionary Weapons. (Interview with Louis Althusser) (in) New Left Review N° 64 November-December 1970] [Interview with Louis Althusser by Maria Antonietta Macciocchi, 1968]