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

The high stage of world-industrial development in capitalistic production finds expression in the extraordinary technical development and destructiveness of the instruments of war.

Capitalism, as a result of its own inner contradictions, moves toward a point when it will be unbalanced, when it will simply become impossible.

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.

Freedom only for supporters of the government, only for the members of one party - however numerous they may be - is no freedom at all. Freedom is always and exclusively freedom for the one who thinks differently. Not because of any fanatical concept of 'justice' but because all that is instructive, wholesome and purifying in political freedom depends on this essential characteristic, and its effectiveness vanishes when 'freedom' becomes a special privilege.

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

Friedrich Engels once said: "Bourgeois society stands at the crossroads, either transition to socialism or regression into barbarism." What does "regression into barbarism" mean to our lofty European civilization? Until now, we have all probably read and repeated these words thoughtlessly, without suspecting their fearsome seriousness. A look around us at this moment shows what the regression of bourgeois society into barbarism means. This world war is a regression into barbarism. The triumph of imperialism leads to the annihilation of civilization.