Karl Marx - from "The Eleventh Thesis on Feuerbach"

The philosophers have already perceived the world in various ways; the point is to change it.
Karl Marx
Workers of the world unite, you have nothing to lose but your chains.
Karl Marx
From each according to their ability, to each according to their need.
Karl Marx
Philosophy is to the real world as masturbation is to sex.
Karl Marx
The oppressed are allowed once every few years to decide which particular representatives of the oppressing class are to represent and repress them.
Karl Marx
It is not the consciousness of men that determines their beeing, but on the contrary, it is their social being that determines their consciousness.
Karl Marx - The Eighteenth Brumaire of Louis Bonaparte (by Karl Marx)
The tradition of all the dead generations weighs like a nightmare on the brain of the living.
Karl Marx - Urban Dictionary, under "Religion."
Religion is the opiate of the masses.
Karl Marx
Reason has always existed, but not always in a reasonable form.

- Karl Marx - from "The Eleventh Thesis on Feuerbach"