We may not do as other parties, because we are not like the others. We are – and this cannot be too often repeated – separated from all other parties… - Wilhelm Liebknecht

Our program was a scientific one it must be constantly changed at minor points to meet the continuous advance of science. And I maintain that no man – Marx, in spite of his comprehensive and deep intellect, as little as any other – can bring science to final perfection; and this position is for everyone who understands the nature of science a foregone conclusion. No socialist, therefore, has the right to condemn attacks on the theoretical ideas of the Marxian teachings or to excommunicate any one from the party because of such attacks. But it is wholly different when such attacks imply a complete overturning of our whole conception of society, as, for example, is the case with Bernstein. Then vigorous defense is in order. Far more dangerous than theoretical assaults are practical disavowals of our principles. Theoretical discussions interest only a comparatively small portion of our membership; whereas practical disavowal of principles and tactical offenses against the party program touch every party comrade and arouse the attention of every party comrade; and when they are not quickly checked and corrected they bring confusion into the whole party.

The correctness of the so-called materialistic conception of history, which considers the political development as dependent on the economic, cannot be brought more strikingly and convincingly to the mind than by the change which in the course of the Nineteenth century has been wrought in the bourgeoisie. It can be demonstrated with the greatest precision how with the change in the productive relations a change of political view and attitude has taken place in the bourgeoisie. Every step forward in economic development has been a step forward in the development of class antagonisms and a step in the approach of the bourgeoisie towards its old enemies, the landlords and priests, and a step in drawing away from the rising proletariat, which in order to effect its emancipation, must advocate equal rights for all men and the democratic principles formerly supported by the bourgeoisie. The moment the proletariat steps forth as a class separate from the bourgeoisie and having interests opposed to it, from that moment the bourgeoisie ceased to be democratic.

The purity of our principles, the idealism of our struggle, these are factors of strengthening and drawing power that have given to us courage for all our battles, and have given to our doctrines an irresistible attraction for all who feel themselves oppressed and have a sense of honor.