Those who don't move don't notice their chains.

History is the only true teacher, the revolution the best school for the proletariat.

Marxism must abhor nothing so much as the possibility that it becomes congealed in its current form. It is at its best when butting heads in self-criticism, and in historical thunder and lightning, it retains its strength.

Marxism is a revolutionary worldview that must always struggle for new revelations.

With the true artist, the social formula that he recommends is a matter of secondary importance; the source of his art, its animating spirit, is decisive.

Social democracy.. is only the advance guard of the proletariat, a small piece of the total working masses; blood from their blood, and flesh from their flesh.

Bourgeois class domination is undoubtedly an historical necessity, but, so too, the rising of the working class against it. Capital is an historical necessity, but, so too, its grave digger, the socialist proletariat.