Friedrich Engels

"Wisdom comes from studying how material conditions shape human behavior."

"Faith in humanity is justified only by examining historical progress."

"The oppressor's laws are tools of their own continued oppression."

"Economic base determines the cultural and intellectual superstructure of society."

"Revolution is not a sudden event but the culmination of historical forces."

"The first historical fact is therefore the production of the means to satisfy these needs, the production of material life itself."

"All that is solid melts into air, all that is holy is profaned."

"The state is nothing but an instrument of oppression of one class by another."

"Without revolutionary theory, there can be no revolutionary practice."

"The working class is revolutionary or it is nothing."

"Religion is the opium of the people."

"In the eyes of the law, a man is either free or not free; the middle state does not exist."

"History repeats itself, first as tragedy, second as farce."

"The more a society develops, the more it perfects the means of warfare."

"Education is the most powerful weapon which you can use to change the world."

"Nature is not something separate from humanity; humans are part of nature."

"The division of labor is the silent war of all against all."

"Under capitalism, art becomes a commodity like any other."

"Knowledge is power, but only when applied to action."

"The real difference is not between those who work and those who don't, but between those who exploit and those who are exploited."

"Technology amplifies human capacity but does not change human nature."

"To be radical is to grasp things by the root."

"The conditions of bourgeois society are too narrow to comprise the wealth created by them."

"Freedom is not a given; it is something that must be constantly fought for."

"In the moment of danger, all classes unite against their common enemy."

"The world will not change if we merely interpret it; we must act to transform it."

"Money is crystallized social relations."

"A spectre is haunting Europe—the spectre of communism."

"The working man has no country."

"Science and reason are the only true guides to understanding reality."