Social democracy is simply the embodiment of the modern proletariat's class struggle, a struggle which is driven by a consciousness of its own historic consequences. The masses are in reality their own leaders, dialectically creating their own development process. 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. And as the entire social democracy movement is only the conscious advance guard of the proletarian class movement, which in the words of the Communist Manifesto represent in every single moment of the struggle the permanent interests of liberation and the partial group interests of the workforce vis à vis the interests of the movement as whole, so within the social democracy its leaders are the more powerful, the more influential, the more clearly and consciously they make themselves merely the mouthpiece of the will and striving of the enlightened masses, merely the agents of the objective laws of the class movement. (The Political Leader of the German Working Classes, Collected Works 2, p.280)