"There is nothing that does not contain contradiction; without contradiction nothing would exist."
On Contradiction, Mao Zedong
"The society which organizes production anew on the basis of free and equal association of the producers will put the whole state machinery where it will then belong—into the museum of antiquities, next to the spinning wheel and the bronze axe."
The Origin of the Family, Private Property, and the State, Friedrich Engels
"We understand that wars cannot be abolished unless classes are abolished and Socialism is created...we fully regard civil wars, i.e., wars waged by the oppressed class against the oppressing class, slaves against slave-owners, serfs against land-owners, and wage-workers against the bourgeoisie, as legitimate, progressive and necessary."
Socialism and War, V.I. Lenin
"We have no compassion and we ask no compassion from you. When our turn comes, we shall not make excuses for the terror."
Suppression of the Neue Rheinische Zeitung, Karl Marx
"They demand that the first act of the social revolution shall be the abolition of authority. Have these gentlemen ever seen a revolution?"
On Authority, Friedrich Engels
"We must display determination, endurance, firmness and unanimity. We must stop at nothing. Everybody and everything must be used to save the rule of the workers and peasants, to save communism."
Speech to Third All-Russia Congress of Textile Workers, V.I. Lenin