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.

Capital is reckless of the health or length of life of the laborer, unless under compulsion from society.

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 human being is in the most literal sense a political animal, not merely a gregarious animal, but an animal which can individuate itself only in the midst of society.

Capitalist production, therefore, develops technology, and the combining together of various processes into a social whole, only by sapping the original sources of all wealth - the soil and the labourer.

Art is always and everywhere the secret confession, and at the same time the immortal movement of its time.