The victory of socialism will not descend like fate from heaven.

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.

The more that social democracy develops, grows, and becomes stronger, the more the enlightened masses of workers will take their own destinies, the leadership of their movement, and the determination of its direction into their own hands.

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.

The working classes in every country only learn to fight in the course of their struggles.

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

Those who do not move, do not notice their chains.