Long live international socialism! - 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 supreme importance of tactics and the necessity of maintaining its class struggle character, is something the party has been well conscious of from the beginning. ... We find that in all questions of tactics the thought was continually kept in the foreground that the party must be kept clean from all mixture with all other parties, every one of which, no matter how much they differed from each other or how furiously they fought among themselves, stood upon the ground of bourgeois society as a common basis. This separation of the Social Democracy from all other parties, this essential difference, which silly opponents take as a reason or pretext for declaring us political outlaws, is our pride and our strength.

This is not an end, but only a means to an end.