“The philosophers have only interpreted the world, in various ways. The point, however, is to change it.[These words are also inscribed upon his grave]”

“In a higher phase of communist society, after the enslaving subordination of the individual to the division of labor, and therewith also the antithesis between mental and physical labor, has vanished; after labor has become not only a means of life but life's prime want; after the productive forces have also increased with the all-around development of the individual, and all the springs of co-operative wealth flow more abundantly—only then can the narrow horizon of bourgeois right be crossed in its entirety and society inscribe on its banners: From each according to his ability, to each according to his needs!”

“The theoretical conclusions of the Communists are in no way based on ideas or principles that have been invented, or discovered, by this or that would -be universal reformer. They merely express, in general terms, actual relations springing from an existing class struggle, from a historical movement going on under our very eyes. The abolition of existing property relations is not at all a distinctive feature of communism. All property relations in the past have continually been subject to historical change consequent upon the change in historical conditions.”

“Merely quantitative differences, beyond a certain point, pass into qualitative changes.”

“The bourgeois period of history has to create the material basis of the new world — on the one hand universal intercourse founded upon the mutual dependency of mankind, and the means of that intercourse; on the other hand the development of the productive powers of man and the transformation of material production into a scientific domination of natural agencies. Bourgeois industry and commerce create these material conditions of a new world in the same way as geological revolutions have created the surface of the earth. When a great social revolution shall have mastered the results of the bourgeois epoch, the market of the world and the modern powers of production, and subjected them to the common control of the most advanced peoples, then only will human progress cease to resemble that hideous, pagan idol, who would not drink the nectar but from the skulls of the slain.”

“Both for the production on a mass scale of this communist consciousness, and for the success of the cause itself, the alteration of men on a mass scale is necessary, an alteration which can only take place in a practical movement, a revolution; this revolution is necessary, therefore, not only because the ruling class cannot be overthrown in any other way, but also because the class overthrowing it can only in a revolution succeed in ridding itself of all the muck of ages and become fitted to found society anew.”

“Language is as old as consciousness, language is practical, real consciousness that exists for other men as well, and only therefore does it also exist for me; language, like consciousness, only arises from the need, the necessity, of intercourse with other men.”