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.

Natural science will in time incorporate into itself the science of man, just as the science of man will incorporate into itself natural science: there will be one science.

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.

In bourgeois society capital is independent and has individuality, while the living person is dependent and has no individuality.

Society does not consist of individuals but expresses the sum of interrelations, the relations within which these individuals stand.