The philosophy founded by Karl Marx (1818-83) and Friedrich Engels (1820-95), and condemned as such by the Catholic Church. It is materialism because it holds not only that matter is real but that matter is prior to mind both in time and in fact. Thus mind is said to appear only as an outgrowth of matter and must be explained accordingly. Space and time are viewed as forms of the existence of matter. It is dialectical in claiming that everything is in constant process of self-transformation. Everything is made up of opposing forces whose internal conflict keeps changing what the thing was into something else. Applied to society, the conflicts among people are essential to the progress of humanity, and to be fostered, as preconditions for the rise of the eventual classless society of perfect Communism.