Educational Bureau of the Industrial Workers of the World, Historical Catechism of American Unionism (ca. 1923)
“ Craft unionism is insurance for the boss against very serious embarrasment. Contrariwise, it is a serious handicap and an embarrassment to the working group which it condemns to fight alone; for one set of union workers in an organized employment may strike to adjust a grievance, but the rest of the organized workers, bound by their agreements, remain at work and assist the employer—thus helping to defeat the strikers with whom they are in sympathy to the last heart beat. Nothing on earth, except the craft union system, could induce these workers to scab upon their fellows. ”
