Marxism
The core of Marxist thinking is called Materialism. Materialism is a philosophical view that says that communities develop from the "ground up".  It says that the "higher" qualities of culture (like art, manners, customs, and religions) are actually founded on the "lower" or simpler qualities of life.  These qualities include having enough of what people need to survive, like food and shelter; who has money and what they have to do to get it; who is allowed to work, and who is forced to work.