Revolutions are the locomotives of history.
History repeats itself, first as tragedy, second as farce.
The first requisite for the happiness of the people is the abolition of religion.
The country that is more developed industrially only shows, to the less developed, the image of its own future.
Workers of the world unite; you have nothing to lose but your chains.
It is absolutely impossible to transcend the laws of nature. What can change in historically different circumstances is only the form in which these laws expose themselves.
Nothing can have value without being an object of utility.
The ideas of the ruling class are in every epoch the ruling ideas, i.e., the class which is the ruling material force of society, is at the same time its ruling intellectual force.
The only antidote to mental suffering is physical pain.
In a higher phase of communist society... only then can the narrow horizon of bourgeois right be fully left behind and society inscribe on its banners: from each according to his ability, to each according to his needs.