Plechanov was not blind to the dangers of compromise which must be faced in basing the policy of a movement of the masses upon this reasoning. He argued, however, that there was no choice in the matter at all; that the iron law of historical inevitability and necessity determined the matter. He pointed out that the bourgeoisie, represented by the Constitutional Democrats in the political struggle, were compelled to wage relentless war upon Absolutism, the abolition of which was as absolutely essential to the realization of their class aims as it was to the realization of the class aims of the proletariat. Hence, in this struggle, the capitalist class, as yet too weak to accomplish the overthrow of autocracy and Czarism, and the proletariat, equally dependent for success upon the overthrow of autocracy and Czarism, and equally too weak to accomplish it unaided, had to face the fact that historical development had given the two classes which were destined to wage a long conflict an immediate unity of interest. Their imperative needs at the moment were not conflicting needs, but identical ones. To divide their forces, to refuse to co-operate with each other, was to play the game of the Czar and his associates, argued Plechanov. The Mensheviki favored participation in the Duma elections and co-operation with the liberal and radical bourgeoisie parties, in so far as might be necessary to overthrow the autocracy, and without sacrificing Socialist principles. They pointed out that this position was evidently feared by the bureaucracy far more than the position of the extremists among the Social Democrats and the Socialist-Revolutionists, who refused to consider such co-operation, and pointed to the fact that provocateurs in large numbers associated themselves with the latter in their organizations and preached the same doctrine of absolute isolation and exclusiveness. It will be seen that the position of the Mensheviki was one of practical political opportunism, an opportunism, however, that must be sharply distinguished from what Wilhelm Liebknecht used to call "political cow-trading." No man in the whole history of international Socialism ever more thoroughly despised this species of political opportunism than George Plechanov. To those who are familiar with the literature of international Socialism it will be unnecessary to say that Plechanov was not the man to deprecate the importance of sound theory as a guide to the formulation of party policies. For many years he was rightly regarded as one of the greatest theoreticians of the movement. Certainly there was only one other writer in the whole international movement who could be named as having an equal title to be considered the greatest Socialist theorist since Marx--Karl Kautsky.