The working classes in every country only learn to fight in the course of their struggles.
The existing legal constitution is nothing but the product of a revolution. Revolution is the act of political creation in the history of classes, while constitutional legislation is the expression of the continual political vegetation of a society.
Social democracy seeks and finds the ways, and particular slogans, of the workers' struggle only in the course of the development of this struggle, and gains directions for the way forward through this struggle alone.
Between social reforms and revolution there exists for the social democracy an indissoluble tie. The struggle for reforms is its means; the social revolution, its aim.
History is the only true teacher, the revolution the best school for the proletariat.
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.