A nation that enslaves another forges its own chains.

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.

The product of mental labor - science - always stands far below its value, because the labor-time necessary to reproduce it has no relation at all to the labor-time required for its original production.

Constant labor of one uniform kind destroys the intensity and flow of a man's animal spirits, which find recreation and delight in mere change of activity.

Philosophy stands in the same relation to the study of the actual world as masturbation to sexual love.

The abolition of religion as the illusory happiness of the people is the demand for their real happiness. To call on them to give up their illusions about their condition is to call on them to give up a condition that requires illusions. The criticism of religion is, therefore, in embryo, the criticism of that vale of tears of which religion is the halo.

If the labourer consumes his disposable time for himself, he robs the capitalist.