INTRODUCTION.
The only possible definition of Socialism is the Socialist movement.
Karl Marx wrote in 1875 at the time of the Gotha Convention, where the present German party was founded, that "every step of the real movement is of more importance than a dozen programs," while Wilhelm Liebknecht said, "Marx is dear to me, but the party is dearer."[1] What was this movement that the great theorist put above theory and his leading disciple valued above his master?
What Marx and Liebknecht had in mind was a _social class_ which they saw springing up all over the world with common characteristics and common problems--a class which they felt must and would be organized into a movement to gain control of society.

Fifty years before it had been nothing, and they had seen it in their lifetime coming to preponderate numerically in Great Britain as it was sure to preponderate in other countries; and it seemed only a question of time before the practically propertyless employees of modern industry would dominate the world and build up a new society.

This class would be politically and economically organized, and when its organization and numbers were sufficient it would take governments out of the hands of the old aristocratic and plutocratic rulers and transform them into the instruments of a new civilization.

This is what Marx and Liebknecht meant by the "party" and the "movement." From the first the new class had been in conflict with employers and governments, and these struggles had been steadily growing in scope and intensity.

Marx was not so much interested in the immediate objects of such conflicts as in the struggle itself.